GEN. BIOLOGY: THE CELL AND THE CELL THEORIES

CELL AND THE CELL THEORIES

1. THE CELL theory Major Parts of the Cell &

2. LEARNING TARGETS 1.Describe the general features of the cell. 2.Create a timeline of the discovery of the cell. 3.Identify the three proponents of the cell theory. 4.Distinguish the different structural components of the plasma membrane, cell wall and organelles.

3. WHAT IS Cell ?

4. Cell Basic and fundamental unit of life , it possesses a highly organized structure that enables it to carry out its vital functions.

5. One brick has no significant purpose... ...but bricks, when combined together, become useful.

6. Similar to bricks, cells, when combined together, perform functions necessary for life.

7. Cell Theory

8. GUESS WHAT? Complete the three basic components of the cell theory by arranging these words in proper order.

9. LIVING OF MORE ARE ALL CELLS ONE OR COMPOSED THINGS

10. CELL IS LIFE OF UNIT THE BASIC

11. FROM CELLS CELLS ALL EXIXTING ARISE PRE-

12. Have you ever wonder how cells were discovered and how they govern the mechanisms of our day-to-day activities?

13. Different scientists paved the way to propose theories about cells, the structural and functional unit of life.

14. S cientists who contributed to the development of cell theory History of the Development of Cell Theory Zacharias Janssen (1585–1632) invented the first primitive microscope.

15. History of the Development of Cell Theory S cientists who contributed to the development of cell theory Robert Hooke (1635–1703) observed cork cells under a microscope.

16. History of the Development of Cell Theory Francesco Redi (1626–1697) disproved the spontaneous generation theory. S cientists who contributed to the development of cell theory

17. History of the Development of Cell Theory S cientists who contributed to the development of cell theory Anton van Leeuwenhoek (1632–1723) observed microorganisms by using his own practical microscope.

18. History of the Development of Cell Theory Matthias Schleiden (1804–1881) proposed that all plants are composed of cells. S cientists who contributed to the development of cell theory

19. History of the Development of Cell Theory Theodor Schwann (1810–1882) proposed that all animals are composed of cells. S cientists who contributed to the development of cell theory

20. History of the Development of Cell Theory Rudolf Virchow (1821–1902) proposed that all cells come from pre-existing cells. S cientists who contributed to the development of cell theory

21. __________1. All cells come from pre-existing cells(1858). __________2. All animals are made up of cells (1839). __________3. All plants are made up of cells (1838). __________4. Tiny living organisms are observed (1676). __________5. Thousands of tiny empty chambers in cork are called cells (1665).

22. How do you think were the works of different scientists compiled and synthesized to develop the cell theory?

23. The Three Principles of Cell Theory Principle 1: Every living organism consists of one or more cells. Organism may be unicellular (left) or multicellular (right) based on their level of complexity.

24. The Three Principles of Cell Theory Principle 2: The cell is the fundamental unit of life. It is the smallest structural and functional unit in all organisms.

25. The Three Principles of Cell Theory Principle 3: Cells come from pre-existing cells. Cells contain hereditary material, which they pass to their daughter cells when they divide.

26. The principles of the cell theory disproved the long-held belief of many scientists about the theory of spontaneous generation.

27. aCTIVITY TIME!

28. WHO AM I? Identify the scientists based from their respective works .

29. __________1. All cells come from pre-existing cells(1858). __________2. All animals are made up of cells (1839). __________3. All plants are made up of cells (1838). __________4. Tiny living organisms are observed (1676). __________5. Thousands of tiny empty chambers in cork are called cells (1665).

30. 1. What are the cell theor ies and what does it state? ____________________________________________________ 2. What do we call the basic generalizations that are accepted by modern science about cell? ____________________________________________________ 3. Among the scientists, who advanced the cell theory with his conclusion that cells could only come from other cells? ____________________________________________________ 4. What discovery is Van Leeuwenhoek noted for? ____________________________________________________ 5. What caused scientists to discover the existence of cells? ____________________________________________________

31. Thank you!

32. Overview of the Cell Size of the cell as compared to other objects

33. Why are cells so small? Does their small size have something to do with their function?

34. General Functions of the Cell

35. General Functions of the Cell Regulation of the Internal Environment Acquisition and Utilization of Energy Responsiveness to Their Environment Protection and Support Homeostasis An organism’s ability to keep a constant internal state is called homeostasis. Maintenance of these conditions, is important because most cells of an organism require a specific set of conditions to function normally.

36. General Functions of the Cell Regulation of the Internal Environment Acquisition and Utilization of Energy Responsiveness to Their Environment Protection and Support Homeostasis Perspiration serve as the cooling system to remove excess heat in the body. Shivering generates metabolic heat. Normal body temperature

37. General Functions of the Cell Regulation of the Internal Environment Acquisition and Utilization of Energy Responsiveness to Their Environment Protection and Support Chemical Energy It is stored in the bonds present in food molecules, and it will be converted by the cells into more usable forms.

38. General Functions of the Cell Regulation of the Internal Environment Acquisition and Utilization of Energy Responsiveness to Their Environment Protection and Support Chemical Energy Energy is needed by various cells to perform their functions. heart cells to pump blood intestinal cells to digest food skeletal cells to initiate motion nerve cells to conduct information

39. General Functions of the Cell Regulation of the Internal Environment Acquisition and Utilization of Energy Responsiveness to Their Environment Protection and Support Responsiveness A cell must first be able to determine the changes that have taken place before deciding the necessary responses that will ultimately result in the maintenance of normal internal conditions.

40. General Functions of the Cell Regulation of the Internal Environment Acquisition and Utilization of Energy Responsiveness to Their Environment Protection and Support Responsiveness A tanned skin means more pigment is released in that area to impart protection to the underlying cells especially UV radiation that can damage DNA.

41. Immune cells impart protection against pathogens and other foreign bodies that may enter the general circulation. General Functions of the Cell Regulation of the Internal Environment Acquisition and Utilization of Energy Responsiveness to Their Environment Protection and Support

42. Components of the Cell: Major Parts of the Cell

43. Overview of the Regions of the Cell The cell has three major divisions, namely, the plasma membrane, the cytoplasm, and the nucleus.

44. Overview of the Regions of the Cell The cell consists of both membrane-bound and non-membrane-bound organelles.

45. How do the major cellular structures help in the different cellular processes?

46. Structural Components of the Plasma Membrane The plasma membrane is the cell’s primary barrier. Plasma Membrane Cytoskeleton Cytoplasm Cell Wall Roles of Lipid Bilayer Roles of Membrane Proteins Structure

47. Structural Components of the Plasma Membrane Plasma Membrane Cytoskeleton Cytoplasm Cell Wall Roles of Lipid Bilayer Roles of Membrane Proteins Structure Cell membrane or plasma membrane separates the cytoplasm from external environment. It comprises the following: glycolipids glycoproteins phospholipids cholesterol membrane proteins

48. Structural Components of the Plasma Membrane Plasma Membrane Cytoskeleton Cytoplasm Cell Wall Roles of Lipid Bilayer Roles of Membrane Proteins Structure Each of the phospholipids consists of the following: head region phosphate group hydrophilic tail region two fatty acid chains hydrophobic

49. Structural Components of the Plasma Membrane Plasma Membrane Cytoskeleton Cytoplasm Cell Wall Roles of Lipid Bilayer Roles of Membrane Proteins Structure Phospholipids make up the phospholipid bilayer. two phospholipid layers Phosphate heads face the cytoplasm and the cell’s exterior. Fatty acid tails are sandwiched.

50. Structural Components of the Plasma Membrane Plasma Membrane Cytoskeleton Cytoplasm Cell Wall Roles of Lipid Bilayer Roles of Membrane Proteins Structure The fluid mosaic model describes the membrane structure. mosaic of different molecules such as proteins, sugars, and cholesterol fluidity due to its natural viscosity

51. Structural Components of the Plasma Membrane Plasma Membrane Cytoskeleton Cytoplasm Cell Wall Roles of Lipid Bilayer Roles of Membrane Proteins Structure Membrane fluidity is determined by: the “ kinks ” in the fatty acid tails of the phospholipids the cholesterol molecules which act as regulators of fluidity

52. Structural Components of the Plasma Membrane Plasma Membrane Cytoskeleton Cytoplasm Cell Wall Roles of Lipid Bilayer Roles of Membrane Proteins Structure Selective permeability is an important property of the lipid bilayer , in which it only allows certain molecules to move into and out of the cell.

53. Structural Components of the Plasma Membrane Plasma Membrane Cytoskeleton Cytoplasm Cell Wall Roles of Lipid Bilayer Roles of Membrane Proteins Structure Lipids Alcohol oxygen nitrogen water small molecules carbon dioxide Permeable

54. Structural Components of the Plasma Membrane Plasma Membrane Cytoskeleton Cytoplasm Cell Wall Roles of Lipid Bilayer Roles of Membrane Proteins Structure polar molecules glucose amino acids proteins large molecules nucleic acids Impermeable

55. Structural Components of the Plasma Membrane Plasma Membrane Cytoskeleton Cytoplasm Cell Wall Roles of Lipid Bilayer Roles of Membrane Proteins Structure Transport proteins in the membrane may either be in the form of carrier proteins or channel proteins

56. Structural Components of the Plasma Membrane Plasma Membrane Cytoskeleton Cytoplasm Cell Wall Roles of Lipid Bilayer Roles of Membrane Proteins Structure channel proteins receptor proteins Membrane Proteins carrier proteins cell recognition proteins passageway of certain molecules change conformation to transport molecules detect invading pathogens binding of molecules to trigger responses

57. The Cytoskeletal Elements Plasma Membrane Cytoskeleton Cytoplasm Cell Wall Microfilaments Intermediate Filaments Microtubules This consists of a network of protein fibers that gives the cell its structural framework. The cytoskeletal elements can be observed by using fluorescence techniques.

58. The Cytoskeletal Elements Plasma Membrane Cytoskeleton Cytoplasm Cell Wall Microfilaments Intermediate Filaments Microtubules In addition to providing a structural framework to the cell, the cytoskeleton also serves other functions such as movement of organelles, macromolecules, and chromosomes.

59. The Cytoskeletal Elements Plasma Membrane Cytoskeleton Cytoplasm Cell Wall Microfilaments Intermediate Filaments Microtubules These consist of helically arranged globular proteins called tubulin . A microtubule is a helix of ɑ-tubulin and β-tubulin subunits.

60. The Cytoskeletal Elements Plasma Membrane Cytoskeleton Cytoplasm Cell Wall Microfilaments Intermediate Filaments Microtubules It radiate from the centrosomes Form spindle fibers that move chromosomes A microtubule is a helix of ɑ-tubulin and β-tubulin subunits.

61. The Cytoskeletal Elements Plasma Membrane Cytoskeleton Cytoplasm Cell Wall Microfilaments Intermediate Filaments Microtubules They consist of long fibers of actin protein, making them the thinnest cytoskeleton. Fluorescent actin microfilaments from mouse embryo

62. The Cytoskeletal Elements Plasma Membrane Cytoskeleton Cytoplasm Cell Wall Microfilaments Intermediate Filaments Microtubules They help facilitate cell and organelle movement. They can help change the shape of the cell. Fluorescent actin microfilaments from mouse embryo

63. The Cytoskeletal Elements Plasma Membrane Cytoskeleton Cytoplasm Cell Wall Microfilaments Intermediate Filaments Microtubules Helps maintain cell shape Anchors the nucleus Intermediate filaments provide structural integrity to the plasma membrane

64. Structural Components of the Cytoplasm Plasma Membrane Cytoskeleton Cytoplasm Cell Wall Cross-section view of a plant cell showing organelles in the cytoplasm This is where all different subcellular structures are suspended.

65. Structural Components of the Cytoplasm Plasma Membrane Cytoskeleton Cytoplasm Cell Wall Cross-section view of a plant cell showing organelles in the cytoplasm It is composed of the cytosol , a semifluid solution that consists of water and inorganic and organic molecules.

66. Structural Components of the Cell Wall Plasma Membrane Cytoskeleton Cytoplasm Cell Wall Cell wall is a rigid structure that surrounds the cell membrane. It helps maintain the shape of cells and prevent them from bursting.

67. Structural Components of the Cell Wall Plasma Membrane Cytoskeleton Cytoplasm Cell Wall Bacterial cell capsule consists of peptidoglycan Most bacteria have cell wall made up of peptidoglycan. The cell wall in some fungi consists of chitin .

68. Structural Components of the Cell Wall Plasma Membrane Cytoskeleton Cytoplasm Cell Wall Plant cell walls prevent the cell from bursting should excess water is absorbed. In plant cells, the cell wall consists of mesh-like cellulose fibers.

69. aCTIVITY TIME!

70. 1. It is a major cell structure that is composed of hydrophilic heads and hydrophobic tails.

71. It is a group of membrane proteins that changes their shape to be able to transport substances into and out of the cell.

72. It is a cytoskeletal element that forms a dynamic scaffolding which assembles when needed and disassembles when not.

73. It is composed of cytosol, a semi-fluid solution that consists of water and organic and inorganic molecules.

74. It is a rigid structure that provides protection and support to bacterial, plant, and fungal cells.