Biology 2382B Lecture Notes - Lecture 6: Atg5, Atg8, Autophagosome

55 views8 pages

ivoryjackal749

29 Jan 2018

School

Department

Course

Professor

For unlimited access to Class Notes, a Class+ subscription is required.

Document Summary

Endocytosis another important portion of the secretory pathway; i. e. bringing things in from the cell surface to internalize extracellular material to recycle membrane. Phagocytosis when a specialized cell engulfs something most cells cannot do this, only specialized cells can. Pinocytosis when a cell engulfs vesicles filled with liquid likewise, most cells cannot do this. Receptor mediated endocytosis receptor binds to ligands (extracellular molecules); then the membrane forms a endocytotic vesicle ligands examined in class: ldl and transferrin. Amphipathic shell composed of a phospholipid monolayer (not bilayer) creates a polar surface because the hydrophilic phospholipid head is at the surface polar surface allows transport through the blood and cells cholesterol amphipathic but mostly hydrophobic. Ldl particle allow for the transport of hydrophobic molecule protein hydrophobic core. Ap1 (adaptor protein 1): transgolgi network late endosome; works with clathrin. Ap2 (adaptor protein 2): endocytosis vesicle at the cytosolic membrane; also works with clathrin. I. e. both adaptor proteins work with clathrin.

Related Questions

Cholesterol is transported in the bloodstream in lipoproteinparticles. There are several classes of lipoprotein particles, butone of the most important classes is called Low-densitylipoproteins (LDL). LDL particles are composed of a single moleculeof a large protein called apolipoprotein, as well as thousands ofcholesterols molecules and phospholipids. Part of theapolipoprotein forms the surface of the particles and faces theaqueous phase, while other parts face the hydrophobic interior ofthe particle where they interact with cholesterol and thehydrophobic tails of the phospholipids. When cells need additionalcholesterol, they produce a receptor protein on the surface oftheir plasma membrane that binds to the apolipoprotein andinitiates the uptake of LDL particles into the cell via a processcalled endocytosis.

1. What is the likely reason that LDL particles are used totransport cholesterol in the blood stream?

a. Cholesterol in LDL particles easily inserts into lipidbilayers

b. Cholesterol id largely insoluble in aqueous solutions

c. Cholesterol is synthesized within LDL particles

d. LDL particles can form lipid rafts in the lipid bilayer

2. What is the most likely location of phospholipids in LDLparticles?

a. Bound to the hydrophilic domain of apolipoprotein

b. In the lipid bilayer that surrounds LDL particles

c. On the surface interacting with the aqueous environment aswell as interacting with the hydrophobic core of the particle

d. Within the hydrophobic core of the particle

3. What best describes the class of protein that apolipoproteinbelongs to?

a. Amphipathic proteins

b. Cell surface proteins

c. Membrane associated protein

d. Multipass membrane proteins

4. What kind of molecule on the surface of the cell would bemost likely to serve as a receptor for LDL particles?

a. a cholesterol binding protein

b. a glycolipid

c. a phospholipid

d. trans membrane protein

5. What conditions would be most likely to trigger increaseduptake of LDL particles by cells?

a. increased glycolipid synthesis

b. increased plasma membrane growth

c. increased protein secretion

d. increase protein synthesis

Biology 2382B Lecture Notes - Lecture 6: Atg5, Atg8, Autophagosome

Document Summary

Get access

Related Documents

Biology 2382B Lecture Notes - Lecture 6: Cholesteryl Ester, Golgi Apparatus, Ldl Receptor

Biology 2382B Lecture Notes - Lecture 6: Transferrin Receptor, Ldl Receptor, Cholesteryl Ester

Biology 2382B Lecture Notes - Lecture 6: Cholesteryl Ester, Transferrin Receptor, Clathrin

Related Questions