1. Ch.7 A Tour of the Cell

2. Nucleus Genetic material... chromatin chromosomesnucleolus: rRNA; ribosome synthesis Double membrane envelope with pores Protein synthesis (mRNA)

3. Ribosomes Protein manufacture Free –cytosol protein function in cell Bound –endoplasmic reticulum –membranes, organelles, and export

4. Endomembrane system, I Endoplasmic reticulum (ER) Continuous with nuclear envelope Smooth ER no ribosomes; synthesis of lipids, metabolism of carbohydrates; detoxification of drugs and poisons Rough ER with ribosomes; synthesis of secretory proteins (glycoproteins), membrane production

5. Endomembrane system, II Golgi apparatus ER products are modified, stored, and then shipped Cisternae: flattened membranous sacs trans face (shipping) & cis face (receiving) Transport vesicles

6. Endomembrane system, III Lysosomes sac of hydrolytic enzymes; digestion of macromolecules Phagocytosis Autophagy: recycle cell’s own organic material Tay-Sachs disease~ lipid-digestion disorder

7. Endomembrane system, IV Vacuoles membrane-bound sacs (larger than vesicles) Food (phagocytosis) Contractile (pump excess water) Central (storage in plants) tonoplast membrane

8. Other membranous organelles, I Mitochondria quantity in cell correlated with metabolic activity; cellular respiration; double membranous (phospholipid); cristae/matrix; intermembrane space; contain own DNA

9. Other membranous organelles, II Chloroplast type of plastid; double membranous; thylakoids (flattened disks); grana (stacked thylakoids); stroma; own DNA

10. Peroxisomes Single membrane Produce hydrogen peroxide in cells Metabolism of fatty acids; detoxification of alcohol (liver) Hydrogen peroxide then converted to water

11. The Cytoskeleton Fibrous network in cytoplasm Support, cell motility, biochemical regulation Microtubules: thickest; tubulin protein; shape, support, transport, chromosome separation Microfilaments : thinnest; actin protein filaments; motility, cell division, shape Intermediate filaments: middle diameter; keratin; shape, nucleus anchorage

12. Centrosomes/centrioles Centrosome: region near nucleus Centrioles: 9 sets of triplet microtubules in a ring; used in cell replication; only in animal cells

13. Cilia/flagella Locomotive appendages Ultrastructure: “9+2” 9 doublets of microtubules in a ring 2 single microtubules in center connected by radial spokes anchored by basal body dynein protein

14. Cell surfaces & junctions Cell wall: not in animal cells protection, shape, regulation Plant cell: primary cell wall produced first middle lamella of pectin (polysaccharide); holds cells together some plants, a secondary cell wall; strong durable matrix; wood (between plasma membrane and primary wall)

15. Extracellular matrix (ECM) Glycoproteins: proteins covalently bonded to carbohydrate Collagen (50% of protein in human body) embedded in proteoglycan (another glycoprotein - 95% carbohydrate) Fibronectins bind to receptor proteins in plasma membrane called integrins (cell communication?)

16. Intracellular junctions PLANTS: Plasmodesmata: cell wall perforations; water and solute passage in plants ANIMALS: Tight junctions~ fusion of neighboring cells; prevents leakage between cells Desmosomes~ riveted, anchoring junction; strong sheets of cells Gap junctions~ cytoplasmic channels; allows passage of materials or current between cells