1. Chapter 7 Cell Structure and Function

2. Anton van Leeuwenhoek Father of the microscope - 1600’s –used lens technology –fabric quality –telescope same time 1st to see life in a drop of water

3. Robert Hooke 1665 1st to examined plant tissue Resembled monastery’s tiny rooms “Cells”

4. Matthias Schleiden 1838 - all plants are made of cells

5. Theodor Schwann 1839 - All animals are made of cells

6. Rudolf Virchow 1855 - Cells come from other preexisting cells

7. The Cell Theory All living things are composed of cells Cells are the basic units of structure and function in living things New cells are produced from existing cells

8. What do all cells have in common? Cell membrane –thin, flexible barrier surrounding the cell Cytoplasm –fluid within the cell Genetic Material

9. Basic Cell Types Prokaryotic Cells –cell membrane –cytoplasm –genetic material (lack a nucleus) –all bacteria Cell membrane cytoplasm Genetic Material

10. Eukaryotic Cells Contain cell membrane, cytoplasm nucleusorganelles all animal, plant, fungi and protists

11. A Closer Look at the Cell Your objective is to… Describe the main functions of each cell structure

12. Cell Wall Plants, bacteria, fungi, algae Provides structure and protection Gas and water exchange Plants - made of the polysaccharide cellulose

13. Nucleu s Controls cell processes Contains DNA –deoxyribose nucleic acid –codes for protein and other molecules

14. Chromatin –DNA bound to protein Chromosomes –chromatin condenses during cell division Nucleolus –make ribosomes Nuclear Envelope –2 layers with pores that allow for the passage of material

16. Cytoskeleton Network of protein filaments (microtubules and microfilaments) Maintains cell shape Cell Movement Intracellular Movement –moves organelles –important during cell division

17. Tracks for organelle movement

18. Cell membrane Endoplasmic reticulum Microtubule Microfilament Ribosomes Mitochondrion Figure 7-11 Cytoskeleton

19. Transportation

20. The Organelles Specialized structures within the cytoplasm of the cell that perform specific jobs

21. Endoplasmic Reticulum 2 types –Rough and Smooth –membrane assemblage Rough –contain ribosomes –certain proteins are modified Smooth –synthesis of lipids

23. Ribosomes Use genetic information to make protein found free in cytoplasm or on RER

24. Golgi Apparatus Receive proteins from RER Use enzymes to attach carbohydrates and lipids to proteins Sent to final destination Construct Lysosomes

26. Lysosomes Contain enzymes that breakdown large molecules into smaller molecules Recycle old organelles and debris

28. Enzyme

29. Recycling

30. Vacuole s Storage units for water, salts, proteins and carbohydrates Provide support for plants “water”

32. Chloroplasts Found in plants and algae photosynthesis 2 membranes Contains DNA

33. Mitochondria Convert food into high-energy compounds (ATP) that the cell uses to power growth, development and movement 2 membranes Contains DNA

35. Animal vs. Plant Cells Plant Cell Nuclear envelope Ribosome (attached) Ribosome (free) Smooth endoplasmic reticulum Nucleus Rough endoplasmic reticulum Nucleolus Golgi apparatus Mitochondrion Cell wall Cell Membrane Chloroplast Vacuole Figure 7-5 Plant and Animal Cells

36. Animal Cell Centrioles Nucleolus Nucleus Nuclear envelope Rough endoplasmic reticulum Golgi apparatus Smooth endoplasmic reticulum Mitochondrion Cell Membrane Ribosome (free) Ribosome (attached) Figure 7-5 Plant and Animal Cells

39. The Cell Membrane Objectives: Describe the structure of the cell membrane Describe how substances move through the cell

40. Cell Membrane Structure Lipid bilayer Regulates entry and exit of materials Protection and support Carbohydrate chains act as idenitification cards

41. Outside of cell Inside of cell (cytoplasm) Cell membrane Proteins Protein channel Lipid bilayer Carbohydrate chains Figure 7-12 The Structure of the Cell Membrane

42. Hydrophobic nonpolar Hydrophilic polar

44. Diffusion Movement of materials from a high concentration to a lower concentration until equilibrium is reached requires no energy What materials diffuse across a cell membrane?

46. Osmosis Diffusion of water across a selectively permeable membrane Types of Solutions –hypertonic - higher concentration of dissolved particles –hypotonic - lower concentration of dissolved particles –isotonic - identical concentration

47. Figure 7-15 Osmosis

48. Continues until the concentrations are equal

49. Solutions outside of the cell…..

50. Problems in Organisms Plants –turgor pressure –rigid vs. wilting Antibiotic effects on bacteria Single Celled Organisms –contractile vacuole –homeostasis Animals –cells bathed in isotonic fluids “blood”

51. Facilitated Diffusion specific protein channels for specific substances that cannot diffuse on their own glucose channel

52. High Concentration Low Concentration Cell Membrane Glucose molecules Protein channel Facilitated Diffusion

53. Active Transport movement of materials from a lower concentration to a higher concentration, requires energy, ATP

54. Molecule to be carried Molecule being carried Energy Figure 7-19 Active Transport-going against concentration gradient. Natural is from high to low.

56. Other examples of active transport

57. Phagocytosis Large particles taken into cell Extension of cytoplasm engulfs large particles outside cell Pocket folds into cell with contents and breaks loose from cell membrane forming vacuole inside cell (in cytoplasm).

58. Unicellular Organisms A single cell is the entire organism Include prokaryotes and eukaryotes Examples include: algae, yeasts, fungi, bacteria

60. Multicellular Organisms Cells are interdependent (like a team) Cell specialization- separate roles for each type of cell (ex. Blood cell, nerve cell, muscle cell) Cells are specialized to perform particular functions within organism

61. Levels of Organization Individual cells  tissues  organs  organ systems  organism Tissue- group of similar cells that perform particular function Organ- groups of tissues working together Organ Systems- group of organs working together to perform specific function (11 major systems in human body)

62. Muscle cell Smooth muscle tissue Stomach Digestive system