2. Chapter 4 Cell Structure and Function

3. 4.1 History of Cell Biology OBJECTIVES:  Name scientists who first observed living and non living cells.  Summarize research that led to cell theory.  State 3 principles of Cell Theory  Explain why cells are basic units of life

4. Discovery of Cells A. Hooke A. Discovered cells in cork B. 1 st to observe dead cells B. Leeuwenhook A. First to observe living cells B. Described first cells as animulcules

5. Cytologist A person that studies cells.

6. II. Cell Theory 1. All organisms are composed of cells. 2. Cells are the basic unit of life (structure and function). 3. Cells come from preexisting cells. http://www.teachertube.com/viewVideo.php?vi deo_id=199363&title=Gotta_Love_The_Cell_T heory&ref=butlerh http://www.teachertube.com/viewVideo.php?vi deo_id=199363&title=Gotta_Love_The_Cell_T heory&ref=butlerh

7. 4.2 Introduction to Cells I. Cell Diversity A. Shape reflects function

8. B. Size – is limited by surface area-to volume ratio

10. II. Basic Parts of a Cell A. Nucleus – surrounded by a nuclear envelope 1. Control center 2. Contains DNA/Chromosomes 3. Controls protein synthesis B. Plasma Membrane 1. Boundary between cell and its environment. – regulates what comes in and goes out 2. Maintains homeostasis 3. Composed of phospholipids (+ & -)

11. Nucleus: control center for the cell

12. Cell MEMBRANE

13. C. Cytoplasm - Semi–fluid where chemical reactions occur.  Region between plasma membrane and nucleus where the membrane bound organelles are located.  Cytosol contains particles such as ribosomes and other non-membrane bound particles.

14. Question of the day – write the question and the correct answer. If you were working for the Center Disease Control and discovered new, highly dangerous pathogen, what information should be presented to the public that may prevent a widespread epidemic of the disease? A. the fatality rate caused by the pathogen B. a report on how the pathogen is transmitted from one organism to another C. pictures showing microscopic images of the pathogen so they will be familiar with it D. a description of the surface receptors found on the pathogen and the immune response

15. Chapter 4 Click below to watch the Visual Concept. Internal Organization of a Cell Section 2 Introduction to Cells http://www.goldiesroom.org/video_archive.htm

16. III. Two Basic Cell Types Prokaryotes – cells that lack a nucleus and membrane bound organelles. Example bacteria.

17. All cells except Bacteria Eukaryotes – Cells with a nucleus and membrane bound organelles

18. Chapter 4 Click below to watch the Visual Concept. Visual Concept Comparing Prokaryotes and Eukaryotes

19. IV. Cellular Organization A. Colonies – groups of cells living together, activities are not coordinated B. Cell Tissues Organs organ systems the complete organism

20. 4.3 Cell Organelles and Features I. Plasma Membrane  Phospholipid bilayer Selectively permeable or semi permeable Regulates what enters and leaves the cell Described by the fluid mosaic model because the lipids move within the bilayer. Transport proteins assist with movement into and out of the cell Sterols in the plasma membrane make it firmer and prevent freezing in low temperatures.

21. Chapter 4 Structure of Lipid Bilayer Section 3 Cell Organelles and Features

22. Chapter 4 Plasma Membrane Membrane Proteins  Cell membranes often contain proteins embedded within the phospholipid bilayer. Section 3 Cell Organelles and Features

23. II. Organelles – cellular structures with specific functions “little organs” A. Nucleolus - Part of the nucleus that produces ribosomes. B. Ribosomes - Bonds amino acids to make proteins. – not membrane bound C. Mitochondria - Cellular respiration to produce energy (ATP). Power House 1. Mitochondrial DNA – Comes from mom

24. 9. Mitochondria = powerhouse of the cell; where cell energy comes from.

25. 4. Ribosomes: grain like bodies on the ER & in the cytoplasm

26. Chapter 4 Click below to watch the Visual Concept. Visual Concept Ribosomes Section 3 Cell Organelles and Features

27. D. Rough Endoplasmic Reticulum -Covered with ribosomes where proteins are produced to be exported from the cell. E. Smooth Endoplasmic Reticulum  Biochemical reactions,  Making and storing lipids  Detoxification of poisons/drugs F. Golgi Apparatus Sorts proteins and package molecules for transport out of the cell.

28. 5.Endoplasmic Reticulum: (called ER) carry proteins and materials within the cell

29. 6. Golgi Body: receives and packages proteins from ER and distributes around cell and body (mailroom)

30. III. Vesicles – have various roles in the cells. A. Lysosomes  Come from the Golgi Apparatus  Contain digestive enzymes  Break down carbs, proteins, nucleic acids, liver lysosomes break down glycogen, white blood cell’s lysosomes break down bacteria.  Autophage – digest worn out organelles  Break down the cell when the cell dies – autolysis

31. B. Peroxisomes Abundant in the liver and kidney cells Neutralize free radicals (organic molecules responsible for aging, tissue damage, and possibly some diseases). Detoxify alcohol and other drugs Break down fatty acids that can be used by the mitochondria as an energy source Produce hydrogen peroxide (H 2 O 2 )

32. C. Other Vesicles Glyoxysomes in seeds break down stored fats for germination. Endosomes form when particles are too large to pass through the plasma membrane, the membrane surrounds the particle, joins with the lysosome for digestion. Food vacuoles store food Contractile vacuoles in protists pump out excessive water.

33. D. Protein Synthesis – making of proteins 1. Proteins are assembled by ribosomes on the rough ER. 2. Vesicles transport proteins to the Golgi apparatus 3. Golgi modifies the protein and packages 4. Vesicles release the proteins that are designated for outside of the cell 5. Vesicles with enzymes remain inside the cell to do the job for which they were created.

34. E. Cytoskeleton – tubes and filaments that give the cell its structure 1. Microtubules –  Thin hollow, made of protein  Hold organelles in place  Maintain cells shape  Act as tracks that guide organelles and molecules 2. Microfilaments  Small solid protein fibers  Contribute to cellular movement

35. 7. Cytoplasm: clear gelatinous fluid inside a cell

36. Chapter 4 Click below to watch the Visual Concept. Visual Concept Cytoskeleton Section 3 Cell Organelles and Features

37. 3. Intermediate Filaments *rods that anchor the nucleus and some other organelles *hair follicles have lots of intermediate filaments. a. cilia – hair like structures used for movement b. Flagella – whip like structure used for movement. c. Centrioles (animal and protista)  Made of microtubules and are used in cell division

38. 4.4 Unique Features of Plant Cells I. Structures A. Cell Wall  made of cellulose  Has pores to allow exchange  Secondary cell walls (wood) B. Central Vacuole  Large, fluid filled sac  Stores water, enzymes, metabolic waste  Can make up 90% of the plant cell’s volume C. Plastids – contain their own DNA

39. Cell WALL

40. 8. Vacuoles: storage area of the cell Plant has one large vacuole Stores food, waste, & enzymes

41. D. Chloroplasts – photosynthesis  thylakoids – membranous sacs containing  Chlorophyll – pigment that captures light energy Endosymbiosis – Mitochondria and chloroplasts have their own ribosomes and DNA. E. Chromoplasts – contain colorful pigments F. Other plastids can store starch

42. 10. Chloroplasts: ONLY IN PLANTS captures sunlight and produces food for the cell

43. II. Comparing cells A. Prokaryotes vs. Eukaryotes Prokaryotes – PRO=NO membrane bound organelles or nucleus Eukaryotes – true cells, membrane bound organelles and a nucleus

44. Two basic types of cells A. Prokaryotic Cells  Do NOT have a nucleus  Bacteria B. Eukaryotic Cells Has a nucleus Has organelles

45. Has Nucleus No Nuclear Membrane Ribosomes and DNA

46. B. Plant cells vs. Animal Cells Plant cells – cell wall, central vacuole and plastids, generally rectangular in shape Animal cells – centrioles and lysosomes, irregular shape http://www.goldiesroom.org/video_archive.htm