G7 ch2.2 the cell

1. The Cell
CHAPTER 2 LESSON 2
P.51-58

2. Vocabulary
•Cell membrane
•Cell wall
•Cytoplasm
•Cytoskeleton
•Organelle
•nucleus

3. Outline
•Review Cells and
cell Theory
•Cell Shape
•Cell Types
–Pro/Eu
–Types of Eu cells
•Cell Parts
–Cell Membrane
–Cell Wall
–Cell Appendages
–Cytoplasm and
Cytoskeleton
•Cell Organelles
–Nucleus
•Chromosomes
•Nuclear envelope
–Ribosomes
–Rough ER
–Smooth ER
–Mitochondria
•ATP
–Chloroplasts
•Glucose
–Golgi Apparatus
•Vesicles
–Vacuoles

4. Cells
•Smallest living unit
•Most are microscopic

5. Cell Size

6. Cell Diversity- ShapeCell Diversity- Shape
•Cells differ widely in shape.
•Size and shape relate to their
function.

7. Principles of Cell Theory
•All living things are made of cells
•Smallest living unit of structure and
function of all organisms is the cell
•All cells arise from preexisting cells
(this principle discarded the idea of
spontaneous generation)

8. Characteristics of All Cells
•A surrounding membrane
•cytoplasm – cell contents in thick fluid
•Organelles – structures for cell function
•Control center with DNA

9. Cell Types
•Prokaryotic
•Eukaryotic

10. Prokaryotic Cells
•First cell type on earth
•Cell type of Bacteria and Archaea
•Most are unicellular organisms
called prokaryotes

11. Prokaryotic Cells
•No nucleus
•DNA floats freely in the cytoplasm
•No organelles, only free floating proteins

12. Eukaryotic Cells
•Nucleus – DNA surrounded by a nucleus
•Include fungi, protists, plant, and animal cells
•Possess many organelles
•Much larger than prokaryotic cells
Protozoan

13. Prokaryote vs. Eukaryote
•Pro = No nucleus
•Eu = Yes, there is a
nucleus

14. Representative Animal Cell

15. Representative Plant Cell

16. Organelles
•In eukaryotic cells
•Cellular machinery
•Different functions

17. Cell Membrane
•All cells
•Protects the inside of a cell from the outside
•Made of proteins and lipids called
phospholids

18. Phospholipids
Protein

19. Movement Across the Plasma Membrane
•Some things move freely in and out of the cell
•Some things are blocked and need proteins to
help them cross the membrane

20. Cell Walls
•Found in plants, fungi, & many protists
•Surrounds plasma membrane
•Gives shape and support

21. Cell Wall Differences
•Stiff structure
•Protects from viruses and other
harmful organisms
•Has holes that connect cell
membranes between cells

22. Cytoplasm
•Fluid inside the cell
•Mostly water and salts
•Cytoskeleton
–Proteins that are the framework of a cell
–Like a skeleton or web of stick-like proteins
–Gives shape
–Helps the cell move

24. Cell Appendages
•Help with movement
–Flagella – tail-like and whips back and forth
–Cilia – fine-hairs that move the cell or
molecules around it

25. Nucleus
•Control center of cell
•Usually largest
organelle
•Double membrane
•Contains
–Chromosomes
–Nucleolus

26. Nuclear Envelope
•Separates nucleus from rest of cell
•Double membrane
•Has pores

27. Nucleolus
•Dark Spot in nucleus
•Forms ribosomes, organelle that makes
proteins

28. DNA
•Hereditary material
•Chromosomes
–tightly wound DNA
•Humans have 23
pairs

29. Endoplasmic Reticulum
•Helps move substances within cells
•Network of interconnected membranes
•Two types
–Rough endoplasmic reticulum
–Smooth endoplasmic reticulum

30. Rough Endoplasmic Reticulum
•Ribosome are attached
•Spreads throughout the cell
•The site of protein production

31. Ribosome
•Attached to the rough ER
–Make proteins
–Attached to rough ER or free floating
–Not surrounded my a membrane
–There are many in a cell

32. Smooth Endoplasmic Reticulum
•No attached ribosomes
•Makes lipids such as cholesterol
–Carbohydrates
–Lipids

33. Golgi Apparatus
•Involved in synthesis of plant cell wall
•Packaging & shipping station of cell

34. Golgi Apparatus Function
1. Prepares proteins for their jobs
2. Packages proteins into vesicles

35. Vesicles
•Many inside the cell
•After a protein is modified in the Golgi Apparatus
a vesicle pinches off containing the proteins
•Transport substances
•Tiny balls of membrane

37. Lysosome
•Specialized Vesicle
•Full of enzymes, proteins that break down
and recycle cell components like old
proteins
•Tiny membrane ball
•Many

38. Vacuoles
•Membrane bound storage sacs
•Plant cells have one large one
•Animal cells have many small ones
•Contents
–Water
–Food
–wastes

39. Energy Processing
Organelles
•Release & store energy
•Types
–Mitochondria
(release energy)
–Chloroplasts
(store energy)

40. Mitochondria
•Hundreds sometimes thousands
•Bound by double membrane

41. Mitochondria
•Break down fuel molecules (cellular respiration)
–Glucose
–Fatty acids
•Release energy
–ATP

42. ATP
•Adenosine triphosphate
•High-energy molecule
•Fuel for cellular processes

43. Chloroplasts
•In plant cells
•Membrane bound
•Uses light to make glucose from CO2 and
H2O

44. Photosynthesis
•Takes place in the chloroplast
•Makes cellular food – glucose

45. Review of Eukaryotic Cells

46. Review of Eukaryotic Cells

48. Cell Transport

49. Cells Have Large Surface
Area-to-Volume Ratio

50. Molecule Movement & Cells
•Passive Transport
•Active Transport
•Endocytosis
(phagocytosis & pinocytosis)
•Exocytosis

51. Passive Transport
•No energy required
•Move due to gradient
–differences in concentration, pressure, charge
•Move to equalize gradient
–High moves toward low

52. Types of Passive Transport
1. Diffusion
2. Osmosis
3. Facilitated diffusion

53. Diffusion
•Molecules move to equalize concentration

54. Osmosis
•Special form of diffusion
•Fluid flows from lower solute concentration
•Often involves movement of water
–Into cell
–Out of cell

55. Solution Differences & Cells
• solvent + solute = solution
•Hypotonic
–Solutes in cell more than outside
–Outside solvent will flow into cell
•Isotonic
–Solutes equal inside & out of cell
•Hypertonic
–Solutes greater outside cell
–Fluid will flow out of cell

57. Facilitated Diffusion
•Differentially permeable membrane
•Channels (are specific) help molecule
or ions enter or leave the cell
•Channels usually are transport proteins
(aquaporins facilitate the movement of
water)
•No energy is used

58. Process of Facilitated Transport
•Protein binds with molecule
•Shape of protein changes
•Molecule moves across membrane

59. Active Transport
•Molecular movement
•Requires energy (against gradient)
•Example is sodium-potassium pump

60. Endocytosis
•Movement of large material
–Particles
–Organisms
–Large molecules
•Movement is into cells
• Types of endocytosis
– bulk-phase (nonspecific)
– receptor-mediated (specific)

61. Process of Endocytosis
•Plasma membrane surrounds material
•Edges of membrane meet
•Membranes fuse to form vesicle

62. Forms of Endocytosis
•Phagocytosis – cell eating
•Pinocytosis – cell drinking

63. Exocytosis
•Reverse of endocytosis
•Cell discharges material

64. Exocytosis
•Vesicle moves to cell surface
•Membrane of vesicle fuses
•Materials expelled

65. End Chapter 5