Cell Biology 203, Week 5
Cell Biology 203, Week 5 BIO203
Popular in Cell Biology
Popular in Biology
This 10 page Class Notes was uploaded by Pratiti Ghosh-Dastidar on Sunday October 2, 2016. The Class Notes belongs to BIO203 at Miami University taught by Dr. James in Fall 2016. Since its upload, it has received 8 views. For similar materials see Cell Biology in Biology at Miami University.
Reviews for Cell Biology 203, Week 5
Report this Material
What is Karma?
Karma is the currency of StudySoup.
You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!
Date Created: 10/02/16
Pg – 39 Membrane lipid biosynthesis o Occurs in the ER Embedded enzymes are involved o 5 steps: i. Fatty acid in cytosol in complex w/ binding protein will bind & escort into membranes to aid hydrophobic portion. ii. CoA transferase adds CoA to fatty acid 1. We have fatty acyl CoA. iii. Acyl transferase aids glycerol 3-P to FA- 1. Release free s 2. We have phosphaticdic acid iv. Phosphatase catalyzes removal of phosphate 1. Have diacyglycerol v. Choline phosphotransferase transfers choline (polar) phosphate. 1. Gives us phosphatidylcholine 2 aditional points a. Proteins integral to membrane b. pL being added to only cytosolic face of membrane i. meaning that full will be asymmetrically larger 1. want to to get some phospholipids to the other ii. side of the membrane (either because of asymmetry or need a specific PL to the other side) issues Pg – 40 Asymmetric Growth a. Causes membrane to curve can be important especially to bind off vesicles but must be kept in check b. Scramablizes catalyze transfer of phospholipid from membrane to other “at random” (via their concentration of gradient ) Generation of compositional asymmetry a. b. Floppase catalyzes transfer of specific PL to Cystolic monolayer i. Flopase goes the other way * Note glycolipids are found on the extracellular face c. d. Floppase catalyzes transfer of specific PL to Cystolic monolayer i. Flopase goes the other way * Note glycolipids are found on the extracellular face How does it get to other parts of endomembrane sys Note how the membrane flips if buds fuses to the other compartment Pg – 41 Other Compartments exchange proteins o Takes from one membrane and puts it into another membrane For membrane bound organelles not part of i.e. mitochondria chloroplast. Membrane Proteins Mem. are scaffolds of in bilayer embedded and attached are proteins allowing for diverse range of specific function Ex) mediated movement of substances o Transporters and channel Ex) anchor to ex. Matrix proteins or things inside cell (ie. Cytoskeleton) Ex) Enzymes (i.e. bionsyn of in ER) How are they attached Trans membrane from one side to other (amphipathic) o Vast majority are alpha helix Monolayer – associated alpha helix o Usually found on cytosolic side o Has amphipathic helix Lipid linked o Covalently attached to lipid all of the pp chain is one side of the membrane Protein attached Attached to a protein that’s attached to bilayer Pg – 42 20 -25 amino acids is long enough to go through membrane side chains usually h. phobic. H2O filled pore inside there’s H2O allows for hydrophillic side chains On the outside there is still hydrophobic o Ex) Bacteriorhodopsin 7 helix per passage Transports hydrogen ion cytosol to cell generating ion gradient then harnesses that energy to make ATP o Retinal (side chain) absorbs photon of light changes shape causes protein to undergo conformation changes to allow proton to pass through changes back to original shape ( proton binds to cytosolic phase as it passes through) Light driven ion pump to ATP Ex) o that folds into cylinder side chains in center are h. phallic fairly large pore to allow things upto a certain size to pass through.
Are you sure you want to buy this material for
You're already Subscribed!
Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'