1. CELLS The Fundamental Units of Life

2. Cell Theory 1.All organisms are composed of 1 or more cells. 2.The cell is the basic living unit, providing organization for all organisms. 3.All cells arise from preexisting cells.

3. Cells Are Small Most are too small to be seen with the unaided eye…so Microscopes are used. A Light Microscope uses visible light shone through glass lenses. A “thin section” of specimen is required. van Leeuwenhoek

4. Principles of Microscopy LIGHT REFRACTION MAGNIFICATION RESOLUTION

6. Cells!

7. CELLS Eukaryotic Cells (animals, plants, fungi, protists) –Complex & relatively large. –Membrane-bound nucleus & organelles. –80-S Ribosomes. Prokaryotic Cells (archaea, bacteria) –Simple & relatively small. –NO Membrane-bound nucleus & organelles. –70-S Ribosomes.

8. CELLS PROKARYOTIC EUKARYOTIC

9. EUKARYOTIC CELLS Organelles = “little organs” (not really) Membrane-bound

10. ORGANELLES Nucleus –Isolates the DNA & provides access to its hereditary information. –The “control center” of the cell (Transcription).

11. Nucleus 1.Nuclear Envelope (a double membrane) with Pores. 2.Nucleolus rRNA Proteins Ribosomes 3.Nucleoplasm with Chromatin/Chromosomes.

12. Ribosomes Not true organelles, more “structures”. Protein factories. 2 sub-units. Free (in cytoplasm), more for intracellular activities. Bound (on E.R.), often for extracellular activities (secretion) & packaging within certain organelles.

13. Endomembrane System Synthesis of Proteins & their transport. Packaging of Proteins for transport out of the cell (secretion) or to other areas of the cell. Modification of Proteins. Transport of lipids, lipoproteins, glycoproteins, etc.

14. Endomembrane System 1.Endoplasmic Reticulum (E.R.) –Rough E.R. –Smooth E.R. 2.Golgi Apparatus 3.Vesicles –Lysosomes (also, nuclear envelope, vacuoles, and plasma membrane)

15. Endoplasmic Reticulum Network of interconnected membranes (continuous with the nuclear envelope). Flattened or tubular.

16. Rough E.R. The site of protein manufacture & initial modification, particularly of secretory proteins. Formation (budding) of Transport Vesicles.

17. Smooth E.R. Modification of proteins & formation of Lipids. –Lipid-derived hormones (steroids) are synthesized, including sex hormones (testosterone, etc.) in certain glands. –Detoxification (drugs, alcohol, caffeine, etc. ) in liver cells.

18. Golgi Apparatus Major modification, sorting, & shipping of ER-produced items (esp. for secretion). Addition of non-protein portions to protein molecules.

19. Lysosomes Vesicles carrying digestive enzymes – hydrolytic (proteolytic) enzymes. Animal Cells. Digestion of food brought in by phagocytosis.

20. Lysosomes Digestion and recycling of old & damaged organelles within the cell: Autophagy.

21. Endomembrane System

22. Vacuoles Large vesicles with particular functions. –Food Vacuoles. –Contractile Vacuoles. –Central Vacuole w/ tonoplast in Plant Cells. Storage. Dissolved Solutes. Dumping Ground. Protection. Shape.

23. Mitochondrion Site of cellular respiration = energy production. Carbohydrates ATP Not part of endomembrane system. Have their own DNA, RNA, Proteins, and Ribosomes (70-S). Grow and reproduce independently. Animals, Plants, Fungi, Protists.

24. Mitochondrion Surrounded by a double membrane – an envelope. Outer Membrane Inner membrane (Cristae) Matrix

25. Chloroplast Site of Photosynthesis = acquisition of chemical energy from sunlight. Sunlight + CO 2 Carbohydrates A plastid (not part of endomembrane system). Have their own DNA, RNA, Proteins, and Ribosomes (70-S). Grow and reproduce independently. Plants, Protists.

26. Chloroplast Surrounded by a double membrane – an envelope. Inner Membrane (Grana composed of stacked Thylakoids) Stroma Outer Membrane

27. Cytoskeleton Fiber-like structures that lend organization. Support (providing a scaffolding onto which organelles & vesicles can be organized). Shape (maintain particular shape depending on the cell’s location and/or function). Transport of materials around or out of the cell. Motility of the whole cell from one location to another.

28. Cytoskeleton Microtubules Microfilaments Intermediate Filaments Keratin Subunits Tubulin Actin Keratin

29. Cytoskeleton Permanent –Flagella –Cilia –Muscle Contraction –Scaffolding & Shape Maintenance

30. Cytoskeleton Transient –Spindle Fibers –Transport filaments

31. Cell Wall OUTSIDE the Cell Membrane (technically, outside the cell!) Various proteins & glycoproteins in Prokaryotes. Cellulose in Plants. Chitin in Fungi.

32. Eukaryotic Cell

33. Endosymbiont Theory

34. Onion Cells