MICROSCOPY and THE DISCOVERY OF THE CELL.pptx

MICROSCOPY

1. MICROSCOPY and THE DISCOVERY OF THE CELL

2. Robert Hooke – a 30 year old English botanist at that time (1665), examined a thin slice dried cork tissue using a very simple microscope. It was this memorable event that gave birth to the science of cell biology which also paralleled the invention and improvement of microscope. Other scientist that followed him confirmed that all living things are made up of cells. Since cells are extremely small, it is not surprising that the discovery of these tiny units came after the invention of the microscope .

3. Timeline of the Microscope

4. 1590 – HANS JANSSEN and HIS SON, ZACHARIAS JANSSEN , placed multiple lenses in a tube and found out that objects seen through the tube appear greatly enlarged.

5. 1609- GALILEO GALILEI invented a compound microscope using convex and concave lenses

6. 1625 - this was the first time the term microscope was used by GIOVANNI FABER to refer to the compound microscope of GALLEO.

7. 1665 – ROBERT HOOKE , ENGLISH physicist coined the term “CELL”. He was the first to see a plant cell under a single lens simple microscope.

8. 1676 – ANTONIE VAN LEEWENHOEK – first to see living cells using his own single lens microscope. He examined blood cells, yeast and insects.

9. 1830 – JOSEPH LISTER reduced spherical aberrations by using several weal lenses together at certain distances to get a good magnification without blurring the image.

10. 1874 – ERNST ABBE introduced a mathematical formula that correlates resolving power to the wavelength of light. It made the calculation of the theoretical maximum resolution of a microscope possible.

11. 1931 – ERNST RUSKA and MAX KNOLL designed and built the first transmission electron microscope. It can visualize objects as small as the diameter of an atom

12. 1932 – FRITS ZERNIKE invented the first phase contrast illumination which allows the imaging of transparent samples. Objects can be seen even without staining.

13. 1942 – ERNST RUSKA invented the first scanning electron microscope. It transmits a beam of electrons across the surface of a specimen.

14. 1957 – MARVIN MINSKY introduced the principle of confocal imaging, which gives a resolution that is higher than that of conventional light.

15. 1972 – GODFREY HOUNSFIELD and ALLAN CORMACK developed the COMPUTERIZEDAXIAL TOMOGRAPHY SCANNER (CAT). It can generate cross-sectional views and three-dimensional images of internal organs and structures.

16. 1978 – THOMAS and CHRISTOPH CREMER developed the first practical confocal laser scanning microscope. This instrument uses focused laser beams to scan objects.

17. 1981 – GERD BINNIG and HEINRICH ROHRER invented the scanning tunnelling microscope (STM). It can visualize individual atoms within materials.

18. 1986 – ERNST RUSKA won the NOBLE PRIZE for his contributions to the study of microscopy. A noble prize was also awarded to GERD BINNIG and HEINRICH ROHRER.

19. 1992 – DOUGLAS PRASHER cloned the green fluorescent protein that he used in fluorescence microscopy.

20. 1993 – 1996 STEFAN HELL pioneered the first super-resolution microscopy.

21. 2010 – RESEARCHERS at the university of California, Los Angeles used a cryoelectron microscope to see the atoms of a virus.

22. 2014 – ERIC BETZIG, STEFFAN HELL and WILLIAM MOERNER got the NOBLE PRIZE in CHEMISTRY for the super microscopes the invented. It can see matter smaller than 0.2 um.

23. PARTS OF A LIGHT MICROSCOPE

24. 1. MECHANICAL PART – Parts of the microscope that are involved i9n giving support or strength to the instrument. These are also the parts that are movable and can be adjusted.

25. BODY TUBE - a hollow tube through which light passes from the objective to the eyepiece REVOLVING NOSEPIECE – holds the objectives. It can be rotated to select the appropriate objective. The lenses must be CLICKED into place to successfully view a specimen. ARM – connects the base and the body tube together. It serves as a handle for carrying the microscope. STAGE - the platform where the slide or specimen to be examined is placed. It has an opening at the center that allows light to pass from below to the specimen. STAGE CLIPS – holds the slide in place BASE – the part where the microscope is firmly anchored. It gives support to the whole microscope and is the part where the illuminators are attached. INCLINATION JOINT – a joint found in some microscopes at which the arm is attached to the pillar of the microscope. It is used for tilting the microscope.

26. 2. ILLUMINATING PARTS MIRROR – Reflects light from the surroundings to the specimen on the stage. CONDENSER – concentrates the light from the light source or mirror onto the object of specimen being studied. It is located below the stage, and it is held in place by a rack. IRIS DIAPHRAGM – regulates the amount of light that reaches the specimen. It is attached beneath the condenser.

27. 3. MAGNIFYING PARTS EYEPIECE or OCULAR – the part through which an observer looks to view a specimen. OBJECTIVES – the main lenses that magnify the specimen being observed.

28. KEY POINTS in CELL THEORY CELLS ARE THE SMALLEST UNIT OF LIFE. ALL LIVING THINGS ARE COMPOSED OF ONE OR MORE CELLS. CELLS ARE THE BASIC UNIT OF ORGANIZATION OF ALL ORGANISMS. CELLS COME ONLY FROM PREEXISTING CELLS. CELLS CARRY AND PASS ON TO THE OFFSPRING HEREDITARY UNITS DURING CELL DIVISION. ALL CELLS ARE RELATIVELY THE SAME IN TERMS OF CHEMICAL COMPOSITION AND METABOLIC ACTIVITY.

29. CELL SHAPE

30. INTERNAL ORGANIZATION OF CELLS Cells vary in terms of internal organization. PLANT CELL and ANIMAL CELL THERE CELLS SHOW GREAT VARIATIONS IN PARTS BECAUSE THEY FUNCTION DIFFERENTLY TO PERFORM SPECIFIC TASK. HUMAN BODY CARRIES DIFFERENT KINDS OFF CELLS. EACH IN THE HUMAN BODY IS SPECIALIZED AND ADAPTED FOR PARTICULAR JOB.

31. QUIZ: 1. WHO IS CONSIDERED THE ENGLISH FATHER OF MICROSCOPY? A. ROBERT HOOKE C. ROBERT BROWN B. HANS JANSSEN RUDOLF VIRCHOW 2. WHICH OF THE FOLLOWINGIS NOT A TENENT OF THE CELL THEORY? A.ALL LIVING THINGS ARE MADE UP OF CELLS B. ALL LIVING THINGS ARE COMPOSED OF ATOMS C.ALL CELLS COME FROM PREEXIXTING CELLS D. CELLS ARE THE BASIC FUNCTIONAL UNIT OF LIFE.

32. 3. WHAT PART OF THE MICROSCOPE FOCUSES LIGHT ON THE SPECIMEN BEING OBSERVED? A. MIRROR C. CONDENSER B. OBJECTIVE LENS D. OCULAR 4. WHO WAS THE DUTCH MICROSCOPE MAKER WHO PIONEERED THE STUDY OF PROTOZOA? A. LOUIS PASTEUR C. GALILEO GALILEI B. ROBERT HOOKE D. ANTONIE VAN LEEUWENHOEK 5. WHICH OF THE FOLLOWING IS MEASURED IN CUBIC CENTIMETERS? A. AREA C. WEIGHT B. VOLUME D. HEIGHT

33. CELL STRUCTURE AND THEIR FUNCTIONS IMPROVEMENTS IN MICROSCOPY AND THE STUDY OF CELLS LED TO THE CLASSIFICATION OF ORGANISMS ACCORDING TO CELLULAR ARGANIZATION AND ARCHITECTURE. WHEN SCIENTIST STARTED USING MICROSCOPE, TWO BASIC CELLULAR ACHITECTURES WERE DISCOVERED: PROKARYOTIC CELLS EUKARYOTIC CELLS

34. PROKARYOTIC CELLS HAVE RELATIVELY SIMPLE ORGANIZATION THEY ARE MOST MICROSCOPIC MEASURING FROM 1 TO 10 um IN DIAMETERS, AND EXIST IN UNICELLULAR FORM. PROKARYOTE IS DERIVED FROM THE WORD “PRO” and “KRAYON” MEANING “BEFORE” and “KERNEL”. THIS TERM DESCRIBES CELLS NUCLEUS. DO NOT HAVE CELL MEMBRANE-BOUND NUCLEUS. TWO GROUPS OF BACTERIA ARCHAEBACTERIA EUBACTERIA

35. PARTS OF PROKARYOTIC CELLS GLYCOCALYX – AN OUTER LAYER THAT PROVIDES PROTECTION. IT IS AN IMPORTANT VIRULENCE FACTOR SINCE IT PROTECTS DISEASE CAUSING BACTERIA. IT HELPS BACTERIA HOLD ON TO SURFACES AND PROTECTS THEM FROM BEING ENGULFED BY MACROPHAGES. CELL WALL – A STRUCTURE THAT CONFERS RIGIDITY AND SHAPE TO THE CELL. IT IS FOUND OUTSIDE OF THE PLASMA MEMBRANE AND IS COMPOSED OF PEPTIDOGLYCAN. PLASMA MEMBRANE – A STRUCTURES THAT PREVENTS THE LOSS OF WATER AND ELECTROLYTES INSIDE THE CELL. PLASMID – A SMALL, CIRCULAR, EXTRACHROMOSOMAL DNA MOLECULE FOUND IN THE CYTOPLASM.

36. NUCLEOID – THE REGION WHERE DNA IS CONCENTRATED. CYTOPLASM - THE WHOLE INSIDE REGION OF THE CELL WHERE CHROMOSOMES, RIBOSOMES, and OTHER CELLULAR INCLUSIONS ARE SUSPECTED. RIBOSOMES – THE SITE WHERE PROTEINS ARE SYNTHESIZED PILUS ( PLURAL,PILLI) – A SHORT, HAIRLIKE APPENDAGE ON THE SURFACE OF SOME BACTERIA. IT HEPLS BACTERIA ADHERE TO THE SURFACES OF HOST CELLS. FLAGELLUM (FLAGELLA) – A LONG THREADLIKE STRUCTURE THAT FACILITATES MOVEMENT IN BACTERIA. FIMBRIAE – BRISTLE-LIKE FIBERS THAT ARE SHORTER THAN PILI. IT IS PRIMARILY USED FOR BACTERIAL ATTACHMENT TO TISSUE SURFACES.

37. 38 Cytoplasm Cytosol = water Organelles = solids Cytoplasm is really like a Jello fruit salad where the Jello is the cytosol and the fruits (oranges, grapes, bananas, maybe walnuts, etc.) are the organelles.

38. 39 Cell Adhesion Molecules (CAMs) Guide cells on the move Selectin – allows white blood cells to “anchor” Integrin – guides white blood cells through capillary walls Important for growth of embryonic tissue Important for growth of nerve cells Adhesion White blood cell Integrin Selectin Exit Splinter Attachment (rolling) Blood vessel lining cell Carbohydrates on capillary wall Adhesion receptor proteins Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

39. 40 Organelles Endoplasmic Reticulum (ER) Connected, membrane-bound sacs, canals, and vesicles Transport system Rough ER Studded with ribosomes Smooth ER Lipid synthesis Added to proteins arriving from rough ER Break down of drugs Ribosomes Free floating or connected to ER Provide structural support and enzyme activity to amino acids to form protein Membranes Ribosomes Membranes (b) (c) Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

40. 41 Organelles Cilia Short hair-like projections Propel substances on cell surface Flagellum Long tail-like projection Provides motility to sperm Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. a: © Oliver Meckes/Photo Researchers, Inc. © Colin Anderson/Brand X/CORBIS

41. 42 Organelles Golgi apparatus Stack of flattened, membranous sacs Modifies, packages and delivers proteins Vesicles Membranous sacs Store substances Inner membrane Outer membrane Cristae (a) (b) Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. a: © Bill Longcore/Photo Researchers, Inc. Mitochondria Membranous sacs with inner partitions Generate energy

42. 43 Organelles Lysosomes Enzyme-containing sacs Digest worn out cell parts or unwanted substances Peroxisomes Enzyme-containing sacs Break down organic molecules Centrosome Two rod-like centrioles Used to produce cilia and flagella Distributes chromosomes during cell division (a) (b) Centriole (cross-section) Centriole (longitudinal section) Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. a: © Don W. Fawcett/Visuals Unlimited

43. 44 Microfilaments and microtubules Thin rods and tubules Support cytoplasm Allows for movement of organelles Organelles Inclusions Temporary nutrients and pigments Microtubules Microfilaments Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. © M. Schliwa/Visuals Unlimited

44. 45 Cell Nucleus Control center of the cell Nuclear envelope Porous double membrane Separates nucleoplasm from cytoplasm Nucleolus Dense collection of RNA and proteins Site of ribosome production Chromatin Fibers of DNA and proteins Stores information for synthesis of proteins Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Nucleus Nucleolus Chromatin (a) Nuclear pores Nuclear envelope

45. EUKARYOTIC CELLS ARE MORE COMPLEX THAN PROKARYOTIC CELLS MEASURES 10 TO 100um IN DIAMETER BIGER THAN PROKARYOTIC CELLS. THIS CELLS HAVE COMPONENTS THAT ARE SURROUNDED BY MEMBRANES WHICH ARE CALLED ORGANELLS.

46. THE NUCLEUS, THE LARGEST CELL ORGANELLE, ENCLOSES THE GENETIC MATERIAL AND IS SUSPENDED IN THE CYTOPLASM. THE MOST DISTINGUISH FEATURE OF THIS TYPE OF CELL IS COMPARTMENTALIZATION, WHICH IS ACHIVED BY THE ENDOMEMBRANE OF THE SYSTEM THAT OCCUPIES THE INTERIOR OF THE CELL INCLUDING THE MEMBRANE BOUND ORGANELLES. MOST OF THIS ORGANELLES DEPENDENTLY PERFORM THERE MULTIPLE BIOCHEMICAL JOBS, WHICH CAN PROCEED IDEPENDENTLY OR SIMULTANEOUSLY. EXAMPLE : ANIMAL CELLS PLANT CELLS FUNGI

47. CELL STRUCTURE ANS THEIR FUNCTION CELLS VARRY IN MANY ASPECTS. THEY VARY IN SIZE, SHAPE AND COMPLEXITY 3 MAIN PARTS OF CELLS NUCLEUS CYTOPLASM CELL MEMBRANE

48. CELL MEMBRANE SOMETIMES CALLED THE PLASMA MEMBRANE A THIN LAYER THAT SEPARATES THE CELL FROM ITS EXTERNAL ENVIRONMENT. OUTERMOST COVERING OF ANIMAL CELLS AND FUNCTIONS AS SELECTIVE BARRIER THAT REGULATES THE ENTRANCE AND EXIT OF SUBSTANCES INTO AND OUT OF THE CELLS. PERMEABLE MEMBRANE PROVIDE SHAPE AND FLEXIBILITY OF THE CELL

49. 1930 – BRITISH BIOLOGIST HUGH DAVSON and JAMES DANIELLI HYPOTHESIZED THAT THE CELL IS COVERED BY A THIN FLEXIBLE ENVELOPE MADE UP OF PHOSPOLIPID BILAYER PROTIENS. THIS WAS THE CLASSICAL PLASMA MODEL

50. 1972 – JONATHAN SINGER and GARTH NICHOLSON PROPOSED OF THE FLUID MOSAIC MODEL OF THE PLASMA MEMBRANE WHICH REVOLUTIONIZED OUR UNDERSTANDING OF THE NATURE OF THE MEMBRANE. MORE POPULAR THAN THE MODEL OF DAVSON AND DANIELLI MADE POSIBLE BY THE HELP OF MODERN MISCROSCOPE WHICH IS MORE PRESICE IN NATURE.

51. IT STATES THAT AT NORMAL TEMPERATURE, THE PLASMA MEMBRANE BEHAVES LIKE A THIN LAYER OF FLUID COVERING THE SURFACE OF THE CELL AND THAT INDIVIDUAL PHOSPOLIPIDS DIFFUSE RAPIDLY THROUGHOUT THE SURFACE OF A MEMBRANE. IT IS TERMED MOSAIC BECAUSE IT INCLUDES IT INCLUDES INTEGRAL PROTIENS THAT PROTRUDE ABOVE OR BELOW THE LIPID BILAYER, PERIPHERAL PROTIENS, GLYCOLIPID, CHOLESTEROL AND OTHER MOLECULES.

52. GLYOCALYX IS THE EXTERNAL COATING OF THE CELL MEMBRANE AND IS MADE UPO OF GLYCOPROTIENS AND POLYSACCHARIDES. IT SERVE DIFFERENT FUNCTIONS AS SUMMARIZED BELOW. IT PROVIDES PROTECTION IT ENABLES CELL-TO-CELL RECOGNITION IT CONTAINS RECEPTOR OR CONTRACT SITES FOR ENZYMES AND HORMONES IT ALLOWS THE CELL TO RESPOND TO CHANGES IN ELECTRICAL POTENTIALS IT ACTS AS A FILTRATION

53. CYTOPLASM THE REGION OF THE CELL THAT SURROUNDS THE NUCLEUS IS THE CYTOPLASM. A SEMI-FLUID MATRIX AND IT IS THE LARGEST INTERIOR PART OF THE CELL WHERE ORGANELLES AND CELLULAR INCLUSIONS ARE SUSPENDED.

54. 1. CYTOPLASMIC ORGANELLES ENDOPLASMIC RETICULUM (ER) IS A NETWORK INTERCOMMUNICATING CHANNELS COMPOSED OF MEMBRANE-ENCLOSED SACS AND TUBULES IT SERVES AS AN INTRACELLULAR HIGHWAY THROUGH WHICH THE MOLECULES CAN BE TRANSPORTED FROM ONE PART OF THE CELL TO ANOTHER.

55. TWO FORMS OF ENDOPLASMIC RETICULUM: ROUGH ENDOPLASMIC RETICULUM (RER) – LOOKS ROUGH DUE TO THE PRESENCE OF RIBOSOMES ON ITS MEMBRANE SURFACE. SMOOTH ENDPLASTIC RETICULUM (SER) – IS MORE TUBULAR AND NONGRANULAR DUE TO THE ABSENCE OF RIBOSOMES. IS USUALLY INVOLED IN THE SYNTHESIS OF STEROIDS IN GLAND CELLS, BREAKDOWN OF TOXIC SUBSTANCES BY LIVER CELLS, AND REGULATION OF CALCIUM LEVELS IN THE MUSCLE CELLS.

56. 2. GOLGI APPARATUS A SYSTEM OF MEMBRANE, SIMILAR TO ENDOPLASMIC RETICULUM APPEARS AS A SERIES OF FLATTENED SACS WITH A CHARACTERISTICS CONVEX SHAPE. IT IS SORROUNDED BY WITH UMEROUS VESICLES FILLED WITH FLUID AND SUSPENDED AS SUBSTANCES. IT WORKS IN CLOSE ASSOCIATION WITH THE ENDOPLASMIC RETICULUM. IT IS RESPONSIBLE FOR THE PROCESSING, PACKAGING, AND SORTING OF SECRETORY MATERIAL, FOR USE WITHIN THE CELL OR FOR EXOCYTOSIS (CELL SECRETION).

57. 3. MITOCHONDRIO N PLURAL – MITOCHONRIA IS THE POWER PLANT OF THE CELL IT VARIES IN SIZE, SHAPE, AND NUMBER DEPENDING ON THE DEGREE OF CELLULAR ACTIVITY. CONTAINS ENZYMES THAT HELP IN THE CHEMICAL OXIDATION OF FOOD MOLECULES AND PRODUCESS ENERGY IN THE FORM OF ATP. LIVER CELLS HAVE MORE MITOCHONDRIA (2,500) SKIN CELL ONLY HAVE FEW HUNDRED MITOCHONDRIA HAVE THEIR OWN RIBOSOMES AND DNA MEANING NEW MITOCHONDRIA ARAISE ONLY WHEN EXISTING ONES DIVIDE.

58. 4. LYSOSOMES ARE SMALL, SPHERICAL, MEMBRANE BOUND ORGANELLES WHICH CONTAIN VARIOUS KINDS OF ENZYMES. ENZYMES ARE MOLECULES THAT DIGEST PROTIENS, NUCLEIC ACIDS, POLYSACCHARIDES AND LIPIDS. THEY PROTECT A CELL FROM INVADING BACTERIA AND OTHER PATHOGENS. THEY BREAKDOWN DAMAGED OR WORN OUT CELL PARTS. THEY CAN ENGULF AND DIGEST TARGETED MOLECULES. WHEN A MOLECULE IS BROKEN DOWN, THE PRODUCTS PASS THROUGH THE LYSOSOME MEMBRANE AND RETURNED BACK INTO THE CYTOPLASM TO BE RECYCLED.

59. 5. SECRETORY GRANULES ARE LARGE, DENSE GRANULES WITH MEMBRANES. THESE FUSE WITH THE CELL MEMBRANE TO SECRETE SUBSTANCES SUCH AS ENZYMES, PROTIENS AND SIGNALING MOLECULES OUT OF THE CELL. 6. LIPID DROPETS STORE FATTY ACIDS AND STEROLS. THEY TAKE UP MUCH SPACE AND VOLUME IN ADIPOCYTES OR FAT CELLS. THEY APPEAR AS BLACK SPHERICAL BODIES OF VARIYING SIZES WHEN STAINED

60. CELLULAR MACROMOLECULES CELLULAR MACROMOLECULES ARE SUBSTANCES SUSPENDED IN THE CYTOPLASM WITH VARIYING FUNCTIONS AND ARE NOT MEMBRANE-BOUND STRUCTURES. THEIR QUANTITY IS DEPENDENT ON THE CELL TYPE.

61. 1. RIBOSOMES ARE NOT CONSIDERED ORGANELLES BECAUSE THEY ARE NOT SOROUNDED BY MEMBRANES. EACH RIBOSOMES IS AN ASSEMBLAGE OF TWO ORGANIC COMPOUNDS NAMELY PROTIENS AND RNA. THEY ARE THE MOLECULES THAT SYNTHESIZED PROTIENS PROTIENS THAT ARE NEEDED BY THE CELL ITSELF ARE PRODUCED BY THE FREE RIBOSOMES, WHILE PROTIENS THAT WILL BE INSERTED INTO THE CELL MEMBRANES ARE EXPORTED OUTSIDE OF THE CELL ARE PRODUCED BY THOSE ATTACHED TO THE ENDOPLASMIC RETICULUM.

62. 2. CENTROSOMES IS THE PART OPF THE CYTOPLASM THAT PRODUCES MICROTUBULES. IN ANIMAL CELLS, IT FORMS TWO SMALL PARTS CALLED CENTRIOLES. THE CENTRIOLES ARE SMALL CYLINDRICAL STRUCTURES MADE OF SHORT MICROTUBULES ARRANGED IN A CIRCLE. THROUGH THEIR MAIN FUNCTION IS TO ASSIST IN THE CELL DIVISION, STUDIES HAVE SHOWN THAT CERTAIN CELLS CONTINUE TO DIVIDE EVEN WITHOUT THE.

63. 3. CYTOSKELETON PROVIDES MOTILITY AND STRENGHT FOR THE CELL.IT IS A COLLECTIVE TERM FOR THE NETWORK OF FILAMENTS AND TUBULES THAT EXTENDS THROUGHOUT THE CELL.

64. TYPE OF FIBERS COMPRISING THE CYTOSKELETON: A. MICROTUBULES ARE LONG SLENDER, PROTIEN TUBES TOGETHER WITH THE MICROFILAMENTS, THEY FORM THE CYTOSKELETON OR THE FRAMEWORK OF THE CELL. A NETWORK OF MICROTUBULES FORMS THE SPINDLE APPARATUS THAT APPEARS DURING CELL DIVISION. THESE ALSO FORM THE CORES OF THE CILIA AND FLAGELLA OF SPERM CELLS AND PLAYS A ROLE IN MAINTAINING THE CELL SHAPE

65. B. MICROFILAMENTS SUPPORT THE CELL TO MAINTAIN ITS STRUCTURE AND SHAPE, AS IT PROVIDES RESILIENCY AGAINTS FORCES THAT CAN ALTER ITS SHAPE. SPINDLE FIBERS ARE EXAMPLES OF MICROFILAMENTS THAT AID IN THE MOVEMENT OF CHROMOSOMES DURING CELL DIVISION. THEY ARE ALSO IMPORTANT IN THE CYTOPLASMIC STREAMING OR CYCLOSIS.

66. 4. GLYCOGEN GRANULES WHICH ARE ABUNDANT IN LIVER CELLS, PLAY AN IMPORTANT ROLE IN GLUCOSE METABOLISM,.

67. 5. BIOLOGICAL PIGMENTS ARE ESPECIALLY ABUNDANT IN PLANT CELLS, PARTICULARLY IN PHOTOSYNTHETIC CELLS. THESE ARE USUALLY FOUND IN THE PLASTIDS SUCH AS THE CHLOROPLASTIDS, WHERE THE CHLOROPHYLL PIGMENTS ABOUND. IN ANIMALS, PIGMENTS ARE MOSTLY FOUND IN THE CELLS OF THE SKIN, EYES, HAIR AND FEATHERS.

68. NUCLEUS MOST VISIBLE PARET OF EUKARYOTIC CELLS IS THE NUCLEUS. IN AN ANIMAL CELLS, IT IS ROUGHLY SPHERICAL IN SHAPE AND IS GENERALLY LOCATED AT THE CENTER OF THE CELL. IT IS THE SITE WHERE NUCLIEC ACIDS ARE SYNTHESIZED. THE NUCLEUS ALSO SERVES AS THE SITE FOR THE STORAGE OF HERIDITARY FACTORS. IT IS THE SOURCE OF RIBONUCLIEC ACID (RNA), A MOLECULE RESPONSIBLE FOR CONVERTING GENETIC INSTRUCTIONS IN DNA INTO FUNCTIONAL SUBSTANCES SUCH AS PROTIENS. HOWEVER SUCH AS RED BLOOD CELLS AND PLATELETS LOSE THEIR NUCLEUS AS THEY MATURE.

69. NUCLEAR MEMBRANE IT IS COMPOSED OF TWO LAYERS WHICH SEPARATE THE NUCLEUS FROM THE CYTOPLASM. IT CONTAINS RIBOSOMES ON ITS OUTER MEMBRANE. NUCLEOPLASM IS THE DENSE PROTIEN RICH SUBSTANCE INSIDE THE NUCLEUS. IT IS RICH IN PROTIENS AND NUCLEIC ACIDS AND IT IS WHERE rRNA is transcribed AND ASSEMBLED.

70. NUCLEAR PORES ARE OPENINGS IN THE NUCLEAR MEMBRANE. ACTS AS SELECTIVE CHANELS BETWEEN THE CYTOPLASM AND INSIDE THE NUCLEUS, SELECTIVELY ALLOWING MOLECULES THAT COME IN AND OUT OF THE NUCLEUS. CHROMATIN IS FOUND INSIDE THE NUCLEUS WHICH IS MADE UP OF DNA AND PROTIENS AND FORMS CHROMOSOMES DURING CELL DIVISION. CHROMOSOMES CONTAIN GENES INHERITED BY THE OFFSPRING FROM THEIR PARENTS.

71. CHROMATIN FOUND INSIDE THE NUCLEUS MADE UP OF DNA AND PROTIENS AND FORMS CHROMOSOMES DURING CELL DIVISION CHROMOSOMES CONTAIN GENES INHERITED BY THE OFFSPRING FROM THEIR PARENTS. HUMANS HAVE 46 CHROMOSOMES. EACH ORGANISMS HAS ITS OWN SPECIFIC NUMBER OF CHROMOSOMES ABNORMALITIES IN THE CHROMOSOME STRUCTURE OR ABERRATION IN THE CHROMOSOME NUMBER CAN LEAD TO A GENETIC DISORDER OR EVEN DEATH.

72. 84 Hole’s Human Anatomy and Physiology Twelfth Edition Shier w Butler w Lewis Chapter 2 Chemical Basis of Life Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

73. 85 2.1: Introduction Why study chemistry in an Anatomy and Physiology class? - Body functions depend on cellular functions - Cellular functions result from chemical changes - Biochemistry helps to explain physiological processes

74. 86 2.2: Structure of Matter Matter – anything that takes up space and has mass (weight). It is composed of elements. Elements – composed of chemically identical atoms: Bulk elements – required by the body in large amounts Trace elements - required by the body in small amounts Ultratrace elements – required by the body in very minute amounts Atoms – smallest particle of an element

75. 87 Table 2.1 Some Particles of Matter

76. 88 Elements and Atoms All matter is composed of elements Elements are the parts of compounds Elements are: Bulk elements Trace elements Ultratrace elements The smallest parts of atoms are elements

77. 89 Atomic Structure Atoms - composed of subatomic particles: Proton – carries a single positive charge Neutron – carries no electrical charge Electron – carries a single negative charge Nucleus Central part of atom Composed of protons and neutrons Electrons move around the nucleus Electron (e – ) Lithium (Li) Proton (p + ) Neutron (n ) Nucleus + + + - - - Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

78. 90 Atomic Number, Mass Number and Atomic Weight Atomic Number Number of protons in the nucleus of one atom Each element has a unique atomic number Equals the number of electrons in the atom Mass Number The number of protons plus the number of neutrons in one atom Electrons do not contribute to the weight of the atom Atomic Weight Average of mass numbers of the isotopes of an element

79. 91 Isotopes Isotopes Atoms with the same atomic numbers but with different mass numbers Different number of neutrons Oxygen often forms isotopes (O 16 , O 17 , and O 18 )

80. 92 Molecules and Compounds Molecule – particle formed when two or more atoms chemically combine Compound – particle formed when two or more atoms of different elements chemically combine Molecular formulas – depict the elements present and the number of each atom present in the molecule H 2 C 6 H 12 O 6 H 2 O

81. 93 Bonding of Atoms Bonds form when atoms combine with other atoms Electrons of an atom occupy regions of space called electron shells which circle the nucleus For atoms with atomic numbers of 18 or less, the following rules apply: The first shell can hold up to 2 electrons The second shell can hold up to 8 electrons The third shell can hold up to 8 electrons

82. 94 Bonding of Atoms Bonds form when atoms combine with other atoms Electrons of an atom occupy regions of space called electron shells which circle the nucleus For atoms with atomic numbers of 18 or less, the following rules apply: The first shell can hold up to 2 electrons The second shell can hold up to 8 electrons The third shell can hold up to 8 electrons

83. 95 Bonding of Atoms Lower shells are filled first If the outermost shell is full, the atom is stable Lithium (Li) Helium (He) Hydrogen (H) + - - - + + - - - + + + Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

84. 96 Bonding of Atoms Bonds form when atoms combine with other atoms Electrons of an atom occupy regions of space called electron shells which circle the nucleus For atoms with atomic numbers of 18 or less, the following rules apply: The first shell can hold up to 2 electrons The second shell can hold up to 8 electrons The third shell can hold up to 8 electrons

85. 97 Bonding of Atoms: Ions Ion An atom that gains or loses electrons to become stable An electrically charged atom Cation A positively charged ion Formed when an atom loses electrons Anion A negatively charged ion Formed when an atom gains electrons 11p + 12n Sodium atom (Na) Chlorine atom (Cl) 17p + 18n

86. 98 Ionic Bonds An attraction between a cation and an anion Ionic Bonds Formed when electrons are transferred from one atom to another atom + – 11p + 12n Chloride ion (Cl – ) Sodium ion (Na + ) Sodium chloride 17p + 18n Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Na + Cl – Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

87. 99 Covalent Bonds Formed when atoms share electrons Hydrogen atoms form single bonds Oxygen atoms form two bonds Nitrogen atoms form three bonds Carbon atoms form four bonds H ― H O = O N ≡ N O = C = O Hydrogen atom + H Hydrogen molecule H 2 Hydrogen atom H + + + + - - - - Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

88. 100 Bonding of Atoms: Structural Formula Structural formulas show how atoms bond and are arranged in various molecules Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. O O O CO 2 H 2 O O 2 H 2 C H H O O H H

89. 101 Bonding of Atoms: Polar Molecules Polar Molecules Molecule with a slightly negative end and a slightly positive end Results when electrons are not shared equally in covalent bonds Water is an important polar molecule Slightly negative ends Slightly positive ends (a)

90. 102 Hydrogen Bonds Hydrogen Bonds A weak attraction between the positive end of one polar molecule and the negative end of another polar molecule Formed between water molecules Important for protein and nucleic acid structure H H H H H H H H H H O O O O O Hydrogen bonds (b)

91. 103 Chemical Reactions Chemical reactions occur when chemical bonds form or break among atoms, ions, or molecules Reactants are the starting materials of the reaction - the atoms, ions, or molecules Products are substances formed at the end of the chemical reaction NaCl ’ Na + + Cl - Reactant Products

92. 104 Types of Chemical Reactions Synthesis Reaction – more complex chemical structure is formed A + B ’ AB Decomposition Reaction – chemical bonds are broken to form a simpler chemical structure AB ’ A + B Exchange Reaction – chemical bonds are broken and new bonds are formed AB + CD ’ AD + CB Reversible Reaction – the products can change back to the reactants A + B n AB

93. 105 Acids, Bases, and Salts Electrolytes – substances that release ions in water Acids – electrolytes that dissociate to release hydrogen ions in water HCl  H + + Cl - Bases – substances that release ions that can combine with hydrogen ions NaOH  Na + + OH - Salts – electrolytes formed by the reaction between an acid and a base NaCl  Na + + Cl - HCl + NaOH  H 2 O + NaCl

94. 106 Acid and Base Concentration pH scale - indicates the concentration of hydrogen ions in solution Neutral – pH 7; indicates equal concentrations of H + and OH - Acidic – pH less than 7; indicates a greater concentration of H + Basic or alkaline – pH greater than 7; indicates a greater concentration of OH - OH – concentration increases H + concentration increases Acidic H + Relative Amounts of H + (red) and OH – (blue) Basic OH – 2.0 gastric juice 6.0 corn 7.0 Distilled water 8.0 Egg white 10.5 milk of magnesia 11.5 Household ammonia pH 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 Basic (alkaline) Neutral Acidic 3.0 apple juice 4.2 tomato juice 5.3 cabbage 6.6 cow’s milk 7.4 Human blood 8.4 Sodium biocarbonate Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

95. Neutralization and Buffers Neutralization occurs when an acid and base react to form a salt and water in a displacement reaction. HCl + NaOH  NaCl + H 2 O Termed neutralization because water is formed neutralizing the solution. Buffers act as acids when pH is high and bases when pH is low. Carbonic acid-bicarbonate system.

96. 108 2.3: Chemical Constituents of Cells Organic v. Inorganic Molecules Organic molecules Contain C and H Usually larger than inorganic molecules Dissolve in water and organic liquids Carbohydrates, proteins, lipids, and nucleic acids Inorganic molecules Generally do not contain C and H Usually smaller than organic molecules Usually dissociate in water, forming ions Water, oxygen, carbon dioxide, and inorganic salts

97. 109 Inorganic Substances Water Most abundant compound in living material Two-thirds of the weight of an adult human Major component of all body fluids Medium for most metabolic reactions Important role in transporting chemicals in the body Absorbs and transports heat Oxygen (O 2 ) Used by organelles to release energy from nutrients in order to drive cell’s metabolic activities Necessary for survival

98. 110 Inorganic Substances Carbon dioxide (CO 2 ) Waste product released during metabolic reactions Must be removed from the body Inorganic salts Abundant in body fluids Sources of necessary ions (Na + , Cl - , K + , Ca 2+ , etc.) Play important roles in metabolism

99. 111 Organic Substances Carbohydrates Provide energy to cells Supply materials to build cell structures Water-soluble Contain C, H, and O Ratio of H to O close to 2:1 (C 6 H 12 O 6 ) Monosaccharides – glucose, fructose Disaccharides – sucrose, lactose Polysaccharides – glycogen, cellulose

100. 112 Organic Substances Carbohydrates (a) Some glucose molecules (C 6 H 12 O 6 ) have a straight chain of carbon atoms. C C C C C C H O H O O O H H O H H H H H O H H H H C H O O H H O H O H H H H C O H C C C O C H (b) More commonly, glucose molecules form a ring structure. O (c) This shape symbolizes the ring structure of a glucose molecule. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

101. 113 Organic Substances Carbohydrates O (a) Monosaccharide O O O (b) Disaccharide O O O (c) Polysaccharide Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

102. 114 Organic Substances Lipids Soluble in organic solvents; insoluble in water Fats (triglycerides) Used primarily for energy; most common lipid in the body Contain C, H, and O but less O than carbohydrates (C 57 H 110 O 6 ) Building blocks are 1 glycerol and 3 fatty acids per molecule Saturated and unsaturated Glycerol portion Fatty acid portions C O O H C C H H H C H H C H H C H H C H H C H H C H H C H H C H H C H H C H H C H H C H H C H H C H H H C O O H C C H H C H H C H H C H H C H H C H H C H H C H H C H H C H H C H H C H H C H H C H H C H H C H H C H H H C H C H H C H H C H H C H H C H H C H H H C O O H C C H H H C H H C H H C H H C H H H C Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

103. Neutral Fats Triglycerides are formed from a fatty acid and glycerol (a sugar). They are the most plentiful source of stored energy to our bodies . Two types: Saturated- contain only single bonds Unsaturated- contains one(mono) or more(poly) double bonds Short, unsaturated fats are liquids (oils) and come from plants. Long, saturated fats are solid (butter and meat fat) and come from animals .

104. 116 Organic Substances Lipids Phospholipids Building blocks are 1 glycerol, 2 fatty acids, and 1 phosphate per molecule Hydrophilic and hydrophobic Major component of cell membranes C H C O H C H H Glycerol portion (a) A fat molecule O O Fatty acid Fatty acid Fatty acid H C H H H H C H H N O O Fatty acid Fatty acid O P O C H O – Phosphate portion (b) A phospholipid molecule (the unshaded portion may vary) H C H C H H O (c) Schematic representation of a phospholipid molecule Water-insoluble (hydrophobic) “tail” Water-soluble (hydrophilic) “head” Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

105. 117 Organic Substances Lipids Steroids Four connected rings of carbon Widely distributed in the body, various functions Component of cell membrane Used to synthesize hormones Cholesterol (a) General structure of a steroid C C C H 2 C H 2 C C H (b) Cholesterol C CH CH 2 CH 2 CH CH 3 CH 2 H C HC H 2 H 2 CH 2 CH CH 2 CH 3 CH 3 C H 2 C H CH 3 HO C CH 3 CH 2 CH C Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

106. Organic Substances Proteins Structural material Energy source Hormones Receptors Enzymes Antibodies Protein building blocks are amino acids Amino acids held together with peptide bonds 118 H N H C H C O OH S C H H H H N H C H C O OH C C C H H C H C H H C H C H H N H C H C O OH R

107. 119 Four Levels of Protein Structure Pleated structure Coiled structure Amino acids N N N N N H H H H H C C C C O O O C C C C C C O C O N N H H C O C C O C H N N H O O C C C C N N N N H H H O C C C O O C C C H O C C C N C N H O C C H O C C N N N N H H H O C O O C C C H O C H R H R H R H R H R H R H R H R H R H H R H H R H R H R H H R R H H R R C H C H Secondary structure Primary structure Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Organic Substances Proteins Three-dimensional folding H H Tertiary structure Quaternary structure

108. 120 Animation: Protein Denaturation Please note that due to differing operating systems, some animations will not appear until the presentation is viewed in Presentation Mode (Slide Show view). You may see blank slides in the “Normal” or “Slide Sorter” views. All animations will appear after viewing in Presentation Mode and playing each animation. Most animations will require the latest version of the Flash Player, which is available at http://get.adobe.com/flashplayer.

109. 121 Organic Substances Nucleic Acids Carry genes Encode amino acid sequences of proteins Building blocks are nucleotides DNA (deoxyribonucleic acid) – double polynucleotide RNA (ribonucleic acid) – single polynucleotide S P B Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

110. 122 Organic Substances Nucleic Acids S P S P S P S P S P S P B B B B B B S S S S S S P P P P P P B B B B B B (b) S P S P S P S P S P S P B B B B B B (a) Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

111. 123 3.3: Movements Into and Out of the Cell Passive (Physical) Processes Require no cellular energy and include: Simple diffusion Facilitated diffusion Osmosis Filtration Active (Physiological) Processes Require cellular energy and include: Active transport Endocytosis Exocytosis Transcytosis

112. 124 Simple Diffusion Movement of substances from regions of higher concentration to regions of lower concentration Oxygen, carbon dioxide and lipid-soluble substances T ime Solute molecule W ater molecule A B A B (2) (3) Permeable membrane A B (1) Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

113. 125 Facilitated Diffusion Diffusion across a membrane with the help of a channel or carrier molecule Glucose and amino acids Region of higher concentration Transported substance Region of lower concentration Protein carrier molecule Cell membrane Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

114. 126 Animation: How Facilitated Diffusion Works Please note that due to differing operating systems, some animations will not appear until the presentation is viewed in Presentation Mode (Slide Show view). You may see blank slides in the “Normal” or “Slide Sorter” views. All animations will appear after viewing in Presentation Mode and playing each animation. Most animations will require the latest version of the Flash Player, which is available at http://get.adobe.com/flashplayer.

115. 127 Animation: Diffusion Through Cell Membranes Please note that due to differing operating systems, some animations will not appear until the presentation is viewed in Presentation Mode (Slide Show view). You may see blank slides in the “Normal” or “Slide Sorter” views. All animations will appear after viewing in Presentation Mode and playing each animation. Most animations will require the latest version of the Flash Player, which is available at http://get.adobe.com/flashplayer.

116. 128 Osmosis Movement of water through a selectively permeable membrane from regions of higher concentration to regions of lower concentration Water moves toward a higher concentration of solutes T ime Protein molecule W ater molecule A B A B (1) (2) Selectively permeable membrane Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

117. 129 Animation: How Osmosis Works Please note that due to differing operating systems, some animations will not appear until the presentation is viewed in Presentation Mode (Slide Show view). You may see blank slides in the “Normal” or “Slide Sorter” views. All animations will appear after viewing in Presentation Mode and playing each animation. Most animations will require the latest version of the Flash Player, which is available at http://get.adobe.com/flashplayer.

118. 130 Osmosis and Osmotic Pressure Osmotic Pressure – ability of osmosis to generate enough pressure to move a volume of water Osmotic pressure increases as the concentration of nonpermeable solutes increases Isotonic – same osmotic pressure Hypertonic – higher osmotic pressure (water loss) Hypotonic – lower osmotic pressure (water gain) Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. © David M. Phillips/Visuals Unlimited (b) (a) (c)

119. 131 Filtration Smaller molecules are forced through porous membranes Hydrostatic pressure important in the body Molecules leaving blood capillaries Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Capillary wall Larger molecules Smaller molecules Blood pressure Blood flow Tissue fluid

120. 132 Active Transport Carrier molecules transport substances across a membrane from regions of lower concentration to regions of higher concentration Sugars, amino acids, sodium ions, potassium ions, etc. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Carrier protein Binding site (a) (b) Cell membrane Carrier protein with altered shape Phospholipid molecules Transported particle Cellular energy Region of higher concentration Region of lower concentration

121. 133 Animation: Primary Active Transport Please note that due to differing operating systems, some animations will not appear until the presentation is viewed in Presentation Mode (Slide Show view). You may see blank slides in the “Normal” or “Slide Sorter” views. All animations will appear after viewing in Presentation Mode and playing each animation. Most animations will require the latest version of the Flash Player, which is available at http://get.adobe.com/flashplayer.

122. 134 Animation: Secondary Active Transport Please note that due to differing operating systems, some animations will not appear until the presentation is viewed in Presentation Mode (Slide Show view). You may see blank slides in the “Normal” or “Slide Sorter” views. All animations will appear after viewing in Presentation Mode and playing each animation. Most animations will require the latest version of the Flash Player, which is available at http://get.adobe.com/flashplayer.

123. 135 Active Transport: Sodium-Potassium Pump Active transport mechanism Creates balance by “pumping” three (3) sodium (Na+) OUT and two (2) potassium (K+) INTO the cell 3:2 ratio

124. 136 Animation: How the Sodium-Potassium Pump Works Please note that due to differing operating systems, some animations will not appear until the presentation is viewed in Presentation Mode (Slide Show view). You may see blank slides in the “Normal” or “Slide Sorter” views. All animations will appear after viewing in Presentation Mode and playing each animation. Most animations will require the latest version of the Flash Player, which is available at http://get.adobe.com/flashplayer.

125. 137 Endocytosis Cell engulfs a substance by forming a vesicle around the substance Three types: Pinocytosis – substance is mostly water Phagocytosis – substance is a solid Receptor-mediated endocytosis – requires the substance to bind to a membrane-bound receptor Nucleus Nucleolus V esicle Cell membrane Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

126. 138 Endocytosis Cytoplasm V esicle (a) (b) (c) (d) Receptor protein Cell membrane Molecules outside cell Cell membrane indenting Receptor-ligand combination Nucleus Nucleolus Particle Vesicle Phagocytized particle Cell membrane Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

127. 139 Exocytosis Reverse of endocytosis Substances in a vesicle fuse with cell membrane Contents released outside the cell Release of neurotransmitters from nerve cells Nucleus Endoplasmic reticulum Golgi apparatus Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

128. 140 Transcytosis Endocytosis followed by exocytosis Transports a substance rapidly through a cell HIV crossing a cell layer V iruses bud HIV Exocytosis Receptor-mediated endocytosis HIV-infected white blood cells Anal or vaginal canal Lining of anus or vagina (epithelial cells) Virus infects white blood cells on other side of lining Receptor-mediated endocytosis Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Cell membrane

129. 141 3.4: The Cell Cycle Series of changes a cell undergoes from the time it forms until the time it divide Stages: Interphase Mitosis Cytokinesis Apoptosis G 2 phase Prophase Metaphase Anaphase Telophase Cytokinesis Restriction checkpoint Remain specialized Proceed to division S phase: genetic material replicates G 1 phase cell growth Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Mitosis Interphase

130. 142 Interphase Very active period Cell grows Cell maintains routine functions Cell replicates genetic material to prepare for nuclear division Cell synthesizes new organelles to prepare for cytoplasmic division Phases: G phases – cell grows and synthesizes structures other than DNA S phase – cell replicates DNA

131. 143 Mitosis Produces two daughter cells from an original somatic cell Nucleus divides – karyokinesis Cytoplasm divides – cytokinesis Phases of nuclear division: Prophase – chromosomes form; nuclear envelope disappears Metaphase – chromosomes align midway between centrioles Anaphase – chromosomes separate and move to centrioles Telophase – chromatin forms; nuclear envelope forms

132. 144 Mitosis Telophase and Cytokinesis Nuclear envelopes begin to reassemble around two daughter nuclei. Chromosomes decondense. Spindle disappears. Division of the cytoplasm into two cells. Anaphase Sister chromatids separate to opposite poles of cell. Events begin which lead to cytokinesis. Metaphase Chromosomes align along equator, or metaphase plate of cell. Prophase Chromosomes condense and become visible. Nuclear envelope and nucleolus disperse. Spindle apparatus forms. Late Interphase Cell has passed the restriction checkpoint and completed DNA replication, as well as replication of centrioles and mitochondria, and synthesis of extra membrane. Early Interphase of daughter cells— a time of normal cell growth and function. Cleavage furrow Nuclear envelopes Nuclear envelope Chromatin fibers Chromosomes Spindle fiber Centromere Aster Centrioles Late prophase Sister chromatids Microtubules Mitosis Cytokinesis S phase G 1 phase Interphase Restriction checkpoint (a) (b) (c) (d) (e) Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. © Ed Reschke G 2 phase

133. 145 Animation: Mitosis and Cytokinesis Please note that due to differing operating systems, some animations will not appear until the presentation is viewed in Presentation Mode (Slide Show view). You may see blank slides in the “Normal” or “Slide Sorter” views. All animations will appear after viewing in Presentation Mode and playing each animation. Most animations will require the latest version of the Flash Player, which is available at http://get.adobe.com/flashplayer.

134. 146 Cytoplasmic Division Also known as cytokinesis Begins during anaphase Continues through telophase Contractile ring pinches cytoplasm in half

135. 147 Animation: Control of the Cell Cycle Please note that due to differing operating systems, some animations will not appear until the presentation is viewed in Presentation Mode (Slide Show view). You may see blank slides in the “Normal” or “Slide Sorter” views. All animations will appear after viewing in Presentation Mode and playing each animation. Most animations will require the latest version of the Flash Player, which is available at http://get.adobe.com/flashplayer.

136. 148 3.5: Control of Cell Division Cell division capacities vary greatly among cell types Skin and blood cells divide often and continually Neuron cells divide a specific number of times then cease Chromosome tips ( telomeres ) that shorten with each mitosis provide a mitotic clock Cells divide to provide a more favorable surface area to volume relationship Growth factors and hormones stimulate cell division Hormones stimulate mitosis of smooth muscle cells in uterus Epidermal growth factor stimulates growth of new skin Tumors are the consequence of a loss of cell cycle control Contact (density dependent) inhibition

137. 149 Tumors Two types of tumors: Benign – usually remains localized Malignant – invasive and can metastasize; cancerous Two major types of genes cause cancer: Oncogenes – activate other genes that increase cell division Tumor suppressor genes – normally regulate mitosis; if inactivated they are unable to regulate mitosis Cells are now known as “immortal” Normal cells (with hairlike cilia) Cancer cells Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. © Tony Brain/Photo Researchers, Inc.;

138. 150 Animation: How Tumor Suppressor Genes Block Cell Division Please note that due to differing operating systems, some animations will not appear until the presentation is viewed in Presentation Mode (Slide Show view). You may see blank slides in the “Normal” or “Slide Sorter” views. All animations will appear after viewing in Presentation Mode and playing each animation. Most animations will require the latest version of the Flash Player, which is available at http://get.adobe.com/flashplayer.

139. 151 3.6: Stem and Progenitor Cells Stem cell : Can divide to form two new stem cells Self-renewal Can divide to form a stem cell and a progenitor cell Totipotent – can give rise to every cell type Pluripotent – can give rise to a restricted number of cell types Progenitor cell : Committed cell Can divide to become any of a restricted number of cells Pluripotent

140. 152 Stem and Progenitor Cells one or more steps Sperm Egg Fertilized egg Stem cell Stem cell Progenitor cell Progenitor cell Progenitor cell Blood cells and platelets Fibroblasts (a connective tissue cells) Bone cells Progenitor cell Astrocyte Neuron Skin cell Sebaceous gland cell produces another stem cell (self-renewal) Progenitor cell Progenitor cell Progenitor cell Progenitor cell Progenitor cell Progenitor cell Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

141. 153 3.1 From Science to Technology Therapeutic Stem Cells

142. 154 3.7: Cell Death Apoptosis: Programmed cell death Acts as a protective mechanism Is a continuous process

143. 155 Hole’s Human Anatomy and Physiology Twelfth Edition Shier w Butler w Lewis Chapter 4 Cellular Metabolism Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

144. 156 4.1: Introduction Metabolic processes – all chemical reactions that occur in the body There are two (2) types of metabolic reactions: Anabolism Larger molecules are made from smaller ones Requires energy Catabolism Larger molecules are broken down into smaller ones Releases energy

145. 157 4.2: Metabolic Processes Consists of two processes: Anabolism Catabolism

146. 158 Anabolism Anabolism provides the materials needed for cellular growth and repair Dehydration synthesis Type of anabolic process Used to make polysaccharides, triglycerides, and proteins Produces water CH 2 OH H H OH O H OH Monosaccharide + H HO H OH H H OH O H OH Monosaccharide H HO H OH H H OH O H OH Disaccharide H 2 O Water + H HO H H H OH O H OH H O H OH Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. CH 2 OH CH 2 OH CH 2 OH

147. Amino acid N H H C C H R Dipeptide molecule + + Peptide bond Amino acid N H H C C H H H R H O N H H C C H R H O N H C C OH R H O O N H H C C H R N H C C OH R H O O Water Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. O O H 2 O 159 Anabolism H C H Glycerol 3 fatty acid molecules + OH HO H C OH HO H C C C C OH HO H O O C C C O O O H C H Fat molecule (triglyceride) + H C H C O O O H 3 water molecules (CH 2 ) 14 CH 3 (CH 2 ) 14 CH 3 (CH 2 ) 14 CH 3 (CH 2 ) 14 CH 3 (CH 2 ) 14 CH 3 (CH 2 ) 14 CH 3 H 2 O H 2 O H 2 O Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. O

148. 160 Catabolism Catabolism breaks down larger molecules into smaller ones Hydrolysis A catabolic process Used to decompose carbohydrates, lipids, and proteins Water is used to split the substances Reverse of dehydration synthesis CH 2 OH H H OH O H OH Monosaccharide + H HO H OH H H OH O H OH Monosaccharide H HO H OH H H OH O H OH Disaccharide H 2 O Water + H HO H H H OH O H OH H O H OH Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. CH 2 OH CH 2 OH CH 2 OH

149. Catabolism Amino acid N H H C C H R Dipeptide molecule + + Peptide bond Amino acid N H H C C H H H R H O N H H C C H R H O N H C C OH R H O O N H H C C H R N H C C OH R H O O Water Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. O O H 2 O H C H Glycerol 3 fatty acid molecules + OH HO H C OH HO H C C C C OH HO H O O C C C O O O H C H Fat molecule (triglyceride) + H C H C O O O H 3 water molecules (CH 2 ) 14 CH 3 (CH 2 ) 14 CH 3 (CH 2 ) 14 CH 3 (CH 2 ) 14 CH 3 (CH 2 ) 14 CH 3 (CH 2 ) 14 CH 3 H 2 O H 2 O H 2 O Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. O 161

150. 162 4.3: Control of Metabolic Reactions Enzymes Control rates of metabolic reactions Lower activation energy needed to start reactions Most are globular proteins with specific shapes Not consumed in chemical reactions Substrate specific Shape of active site determines substrate Product molecule Active site (a) (b) (c) Substrate molecules Unaltered enzyme molecule Enzyme-substrate complex Enzyme molecule Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

151. 163 Enzyme Action Metabolic pathways Series of enzyme-controlled reactions leading to formation of a product Each new substrate is the product of the previous reaction Enzyme names commonly: Reflect the substrate Have the suffix – ase Examples: sucrase, lactase, protease, lipase Substrate 1 Enzyme A Substrate 2 Enzyme B Substrate 3 Enzyme C Substrate 4 Enzyme D Product Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

152. 164 Cofactors and Coenzymes Cofactors Make some enzymes active Non-protein component Ions or coenzymes Coenzymes Organic molecules that act as cofactors Vitamins

153. 165 Factors That Alter Enzymes Factors that alter enzymes : Heat Radiation Electricity Chemicals Changes in pH

154. 166 Animation: How Enzymes Work Please note that due to differing operating systems, some animations will not appear until the presentation is viewed in Presentation Mode (Slide Show view). You may see blank slides in the “Normal” or “Slide Sorter” views. All animations will appear after viewing in Presentation Mode and playing each animation. Most animations will require the latest version of the Flash Player, which is available at http://get.adobe.com/flashplayer.

155. 167 Regulation of Metabolic Pathways Limited number of regulatory enzymes Negative feedback Inhibition Substrate 1 Substrate 2 Enzyme B Substrate 3 Enzyme C Substrate 4 Enzyme D Product Rate-limiting Enzyme A Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

156. 168 4.4: Energy for Metabolic Reactions Energy is the capacity to change something; it is the ability to do work Common forms of energy: Heat Light Sound Electrical energy Mechanical energy Chemical energy

157. 169 ATP Molecules Each ATP molecule has three parts: An adenine molecule A ribose molecule Three phosphate molecules in a chain Third phosphate attached by high-energy bond When the bond is broken, energy is transferred When the bond is broken, ATP becomes ADP ADP becomes ATP through phosphorylation Phosphorylation requires energy release from cellular respiration Energy transferred and utilized by metabolic reactions when phosphate bond is broken Energy transferred from cellular respiration used to reattach phosphate P P P P P P P Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

158. 170 Release of Chemical Energy Chemical bonds are broken to release energy We burn glucose in a process called oxidation

159. 171 4.5: Cellular Respiration Occurs in a series of reactions: Glycolysis Citric acid cycle (aka TCA or Kreb’s Cycle) Electron transport system

160. 172 Cellular Respiration Produces: Carbon dioxide Water ATP (chemical energy) Heat Includes: Anaerobic reactions (without O 2 ) - produce little ATP Aerobic reactions (requires O 2 ) - produce most ATP

161. 173 Glycolysis Series of ten reactions Breaks down glucose into 2 pyruvic acid molecules Occurs in cytosol Anaerobic phase of cellular respiration Yields two ATP molecules per glucose molecule Summarized by three main phases or events: Phosphorylation Splitting Production of NADH and ATP

162. 174 Glycolysis Event 1 - Phosphorylation Two phosphates added to glucose Requires ATP Event 2 – Splitting (cleavage) 6-carbon glucose split into two 3-carbon molecules Phase 1 priming Phase 2 cleavage Phase 3 oxidation and formation of ATP and release of high energy electrons 2 ADP 2 NADH + H + 2 NAD + 2 NADH + H + 2 NAD + P ATP P P P Glyceraldehyde phosphate Glucose Dihydroxyacetone phosphate 2 4 ADP ATP 4 Fructose-1,6-diphosphate O 2 2 Pyruvic acid 2 Lactic acid To citric acid cycle and electron transport chain (aerobic pathway) Carbon atom Phosphate P P Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. O 2

163. 175 Glycolysis Event 3 – Production of NADH and ATP Hydrogen atoms are released Hydrogen atoms bind to NAD + to produce NADH NADH delivers hydrogen atoms to electron transport system if oxygen is available ADP is phosphorylated to become ATP Two molecules of pyruvic acid are produced Two molecules of ATP are generated Phase 1 priming Phase 2 cleavage Phase 3 oxidation and formation of ATP and release of high energy electrons 2 ADP 2 NADH + H + 2 NAD + 2 NADH + H + 2 NAD + P ATP P P P Glyceraldehyde phosphate Glucose Dihydroxyacetone phosphate 2 4 ADP ATP 4 Fructose-1,6-diphosphate O 2 2 Pyruvic acid 2 Lactic acid To citric acid cycle and electron transport chain (aerobic pathway) Carbon atom Phosphate P P Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. O 2

164. 176 Anaerobic Reactions If oxygen is not available: Electron transport system cannot accept new electrons from NADH Pyruvic acid is converted to lactic acid Glycolysis is inhibited ATP production is less than in aerobic reactions Phase 1 priming Phase 2 cleavage Phase 3 oxidation and formation of ATP and release of high energy electrons 2 ADP 2 NADH + H + 2 NAD + 2 NADH + H + 2 NAD + P ATP P P P Glyceraldehyde phosphate Glucose Dihydroxyacetone phosphate 2 4 ADP ATP 4 Fructose-1,6-diphosphate O 2 2 Pyruvic acid 2 Lactic acid To citric acid cycle and electron transport chain (aerobic pathway) Carbon atom Phosphate P P Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. O 2

165. 177 Aerobic Reactions If oxygen is available: Pyruvic acid is used to produce acetyl CoA Citric acid cycle begins Electron transport system functions Carbon dioxide and water are formed 34 molecules of ATP are produced per each glucose molecule ATP 2 ATP 2 Glucose Pyruvic acid Pyruvic acid Acetyl CoA CO 2 2 CO 2 Citric acid O 2 H 2 O 2e – + 2H + Electron transport chain ATP 32-34 Cytosol Mitochondrion High energy electrons (e – ) and hydrogen ions (H + ) High energy electrons (e – ) and hydrogen ions (h + ) Oxaloacetic acid High energy electrons (e – ) and hydrogen ions (H + ) Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

166. 178 Citric Acid Cycle Begins when acetyl CoA combines with oxaloacetic acid to produce citric acid Citric acid is changed into oxaloacetic acid through a series of reactions Cycle repeats as long as pyruvic acid and oxygen are available For each citric acid molecule: One ATP is produced Eight hydrogen atoms are transferred to NAD + and FAD Two CO 2 produced Citric acid cycle ADP + ATP Pyruvic acid from glycolysis Citric acid (start molecule) Acetyl CoA (replenish molecule) Acetic acid Oxaloacetic acid (finish molecule) Isocitric acid CO 2 CO 2 CO 2 Succinyl-CoA Succinic acid FAD FADH 2 Fumaric acid Malic acid Cytosol Mitochondrion NADH + H + NAD + NADH + H + NAD + NADH + H + NAD + CoA CoA CoA CoA P NADH + H + NAD + P CoA Carbon atom Phosphate Coenzyme A -Ketoglutaric acid Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

167. 179 Electron Transport System ATP ADP + ATP synthase Electron transport chain Energy P 2H + + 2e – 2e – 2H + NADH + H + NAD + 2H + + 2e – FADH 2 FAD O 2 H 2 O Energy Energy Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. NADH and FADH2 carry electrons to the ETS ETS is a series of electron carriers located in cristae of mitochondria Energy from electrons transferred to ATP synthase ATP synthase catalyzes the phosphorylation of ADP to ATP Water is formed

168. 180 Summary of Cellular Respiration Glycolysis Cytosol Mitochondrion A T P 2 Glucose High-energy electrons (e – ) High-energy electrons (e – ) High-energy electrons (e – ) 2e – and 2H + A T P 2 H 2 O O 2 A T P 32–34 CO 2 Pyruvic acid Pyruvic acid 2 CO 2 Acetyl Co A Citric acid Oxaloacetic acid 1 3 4 2 Glycolysis The 6-carbon sugar glucose is broken down in the cytosol into two 3-carbon pyruvic acid molecules with a net gain of 2 ATP and release of high-energy electrons. Citric Acid Cycle The 3-carbon pyruvic acids generated by glycolysis enter the mitochondria. Each loses a carbon (generating CO 2 and is combined with a coenzyme to form a 2-carbon acetyl coenzyme A (acetyl CoA). More high-energy electrons are released. Each acetyl CoA combines with a 4-carbon oxaloacetic acid to form the 6-carbon citric acid, for which the cycle is named. For each citric acid, a series of reactions removes 2 carbons (generating 2 CO 2 ’s), synthesizes 1 ATP, and releases more high-energy electrons. The figure shows 2 ATP, resulting directly from 2 turns of the cycle per glucose molecule that enters glycolysis. Electron Transport Chain The high-energy electrons still contain most of the chemical energy of the original glucose molecule. Special carrier molecules bring the high-energy electrons to a series of enzymes that convert much of the remaining energy to more ATP molecules. The other products are heat and water. The function of oxygen as the final electron acceptor in this last step is why the overall process is called aerobic respiration. Electron transport chain Citric acid cycle Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

169. 181 Carbohydrate Storage Carbohydrate molecules from foods can enter: Catabolic pathways for energy production Anabolic pathways for storage

170. 182 Carbohydrate Storage Excess glucose stored as: Glycogen (primarily by liver and muscle cells) Fat Converted to amino acids Hydrolysis Monosaccharides Energy + CO 2 + H 2 O Glycogen or Fat Amino acids Carbohydrates from foods Catabolic pathways Anabolic pathways Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

171. 183 Summary of Catabolism of Proteins, Carbohydrates, and Fats High energy electrons carried by NADH and FADH 2 Breakdown of simple molecules to acetyl coenzyme A accompanied by production of limited ATP and high energy electrons H 2 O 2e – and 2H + Waste products –NH 2 CO 2 CO 2 Citric acid cycle Electron transport chain Amino acids Acetyl coenzyme A Simple sugars (glucose) Glycerol Fatty acids Proteins (egg white) Carbohydrates (toast, hashbrowns) Food Fats (butter) Pyruvic acid ATP ATP Breakdown of large macromolecules to simple molecules Glycolysis 1 2 3 ATP Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. © Royalty Free/CORBIS. ½ O 2 High energy electrons carried by NADH and FADH 2 Complete oxidation of acetyl coenzyme A to H 2 O and CO 2 produces high energy electrons (carried by NADH and FADH 2 ), which yield much ATP via the electron transport chain Breakdown of simple molecules to acetyl coenzyme A accompanied by production of limited ATP and high energy electrons H 2 O 2e – and 2H + Waste products –NH 2 CO 2 CO 2 Citric acid cycle Electron transport chain Amino acids Acetyl coenzyme A Simple sugars (glucose) Glycerol Fatty acids Proteins (egg white) Carbohydrates (toast, hashbrowns) Food Fats (butter) Pyruvic acid ATP ATP Breakdown of large macromolecules to simple molecules Glycolysis 1 2 3 ATP © Royalty Free/CORBIS. ½ O 2

172. 184 4.6: Nucleic Acids and Protein Synthesis Instruction of cells to synthesize proteins comes from a nucleic acid, DNA

173. 185 Genetic Information Gene – segment of DNA that codes for one protein Genetic information – instructs cells how to construct proteins; stored in DNA Genome – complete set of genes Genetic Code – method used to translate a sequence of nucleotides of DNA into a sequence of amino acids

174. 186 Structure of DNA Two polynucleotide chains Hydrogen bonds hold nitrogenous bases together Bases pair specifically (A-T and C-G) Forms a helix DNA wrapped about histones forms chromosomes G C G G A T C C A P G C P T P P C G P G P C P A P P P Thymine (T) Cytosine (C) Adenine (A) Guanine (G) Nucleotide strand Globular histone proteins Metaphase chromosome Segment of DNA molecule Chromatin (a) Hydrogen bonds (b) (c) Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

175. 187 Animation: DNA Structure Please note that due to differing operating systems, some animations will not appear until the presentation is viewed in Presentation Mode (Slide Show view). You may see blank slides in the “Normal” or “Slide Sorter” views. All animations will appear after viewing in Presentation Mode and playing each animation. Most animations will require the latest version of the Flash Player, which is available at http://get.adobe.com/flashplayer.

176. 188 DNA Replication Hydrogen bonds break between bases Double strands unwind and pull apart New nucleotides pair with exposed bases Controlled by DNA polymerase Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. C C A T C C G G C C G C G A A T T C G C A T Newly formed DNA molecules Region of replication Original DNA molecule G G G G G G G G G C C C C C G A A A T T A A T T T T T A A A T A A T

177. 189 Animation: DNA Replication Please note that due to differing operating systems, some animations will not appear until the presentation is viewed in Presentation Mode (Slide Show view). You may see blank slides in the “Normal” or “Slide Sorter” views. All animations will appear after viewing in Presentation Mode and playing each animation. Most animations will require the latest version of the Flash Player, which is available at http://get.adobe.com/flashplayer.

178. 190 Genetic Code Specification of the correct sequence of amino acids in a polypeptide chain Each amino acid is represented by a triplet code

179. 191 RNA Molecules Transfer RNA (tRNA) : Carries amino acids to mRNA Carries anticodon to mRNA Translates a codon of mRNA into an amino acid Ribosomal RNA (rRNA): Provides structure and enzyme activity for ribosomes Messenger RNA (mRNA): Making of mRNA (copying of DNA) is transcription

180. 192 RNA Molecules Messenger RNA (mRNA) : Delivers genetic information from nucleus to the cytoplasm Single polynucleotide chain Formed beside a strand of DNA RNA nucleotides are complementary to DNA nucleotides (exception – no thymine in RNA; replaced with uracil) Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. DNA RNA S G S C S S S S C G T A S S S S G C A U Direction of “reading” code P P P P P P P P P P

181. 193 Animation: Stages of Transcription Please note that due to differing operating systems, some animations will not appear until the presentation is viewed in Presentation Mode (Slide Show view). You may see blank slides in the “Normal” or “Slide Sorter” views. All animations will appear after viewing in Presentation Mode and playing each animation. Most animations will require the latest version of the Flash Player, which is available at http://get.adobe.com/flashplayer.

182. 194 Animation: How Translation Works Please note that due to differing operating systems, some animations will not appear until the presentation is viewed in Presentation Mode (Slide Show view). You may see blank slides in the “Normal” or “Slide Sorter” views. All animations will appear after viewing in Presentation Mode and playing each animation. Most animations will require the latest version of the Flash Player, which is available at http://get.adobe.com/flashplayer.

183. 195 Protein Synthesis Messenger RNA 1 DNA information is copied, or transcribed, into mRNA following complementary base pairing 2 mRNA leaves the nucleus and attaches to a ribosome 3 Translation begins as tRNA anticodons recognize complementary mRNA codons, thus bringing the correct amino acids into position on the growing polypeptide chain 4 As the ribosome moves along the mRNA, more amino acids are added 5 At the end of the mRNA, the ribosome releases the new protein 6 Amino acids attached to tRNA Polypeptide chain Cytoplasm DNA double helix DNA strands pulled apart Transcription (in nucleus) Translation (in cytoplasm) Nucleus C Codon 1 Codon 2 Codon 3 Codon 4 Codon 5 Codon 6 Codon 7 G G G G G A A A U U C C C C C C G G G A Methionine Glycine Amino acids represented Serine Alanine Threonine Alanine Glycine DNA strand Messenger RNA A T A A T T T A T A T A T A T A T U A U A U A G C C G C G C G C G C G C G C G G C C G C C G U A C G C G G G G G G G G G G C C C C C C C C C C A A A A A T T A A T A T A T A T C G G C G C G C T A T A T A C G A T G C T A C G T A C G C G G C A T T A C G G C T T G C G C G C G C G C G C G C G C G Nuclear pore tRNA molecules can pick up another molecule of the same amino acid and be reused Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. G C C G A G G C U C T C C G A G

184. 196 Protein Synthesis Next amino acid Anticodon Codons Growing polypeptide chain 1 1 2 2 3 3 4 4 5 5 6 6 7 C U G G Ribosome 1 1 2 2 3 3 7 4 4 5 5 6 7 C C C G U C U G C G U Next amino acid Anticodon Codons 1 1 2 2 3 3 4 4 5 5 6 6 7 Peptide bond C U G C G U C C G C G U 6 Messenger RNA Transfer RNA Next amino acid 1 1 2 2 3 3 4 4 5 5 6 7 6 7 U C G G A A A A A A G G G G G G G G C C C C C C C U U U C G G A A A A A A G G G G G G G G C C C C C C C U U U C G G A A A A A A G G G G G G G G C C C C C C C U U U C G G A A A A A A G G G G G G G G C C C C C C C U U The transfer RNA molecule for the last amino acid added holds the growing polypeptide chain and is attached to its complementary codon on mRNA. A second tRNA binds complementarily to the next codon, and in doing so brings the next amino acid into position on the ribosome. A peptide bond forms, linking the new amino acid to the growing polypeptide chain. The tRNA molecule that brought the last amino acid to the ribosome is released to the cytoplasm, and will be used again. The ribosome moves to a new position at the next codon on mRNA. A A new tRNA complementary to the next codon on mRNA brings the next amino acid to be added to the growing polypeptide chain. 2 1 3 4 Messenger RNA Transfer RNA Next amino acid Transfer RNA Messenger RNA Transfer RNA Growing polypeptide chain Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

185. 197 Animation: Protein Synthesis Please note that due to differing operating systems, some animations will not appear until the presentation is viewed in Presentation Mode (Slide Show view). You may see blank slides in the “Normal” or “Slide Sorter” views. All animations will appear after viewing in Presentation Mode and playing each animation. Most animations will require the latest version of the Flash Player, which is available at http://get.adobe.com/flashplayer.

186. 198 4.7: Changes in Genetic Information Only about 1/10 th of one percent of the human genome differs from person to person

187. 199 Nature of Mutations Mutations – change in genetic information Result when: Extra bases are added or deleted Bases are changed May or may not change the protein Code for glutamic acid Mutation Direction of “reading” code Code for valine (a) (b) S S S C T A P P P S S S C T T P P P Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

188. 200 Nature of Mutations Mutations – change in genetic information Result when: Extra bases are added or deleted Bases are changed May or may not change the protein Code for glutamic acid Mutation Direction of “reading” code Code for valine (a) (b) S S S C T A P P P S S S C T T P P P Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

189. 201 Protection Against Mutation Repair enzymes correct the mutations

190. 202 Nature of Mutations Mutations – change in genetic information Result when: Extra bases are added or deleted Bases are changed May or may not change the protein Code for glutamic acid Mutation Direction of “reading” code Code for valine (a) (b) S S S C T A P P P S S S C T T P P P Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

191. 203 Inborn Errors of Metabolism Occurs from inheriting a mutation that then alters an enzyme This creates a block in an otherwise normal biochemical pathway