Question

8.) which of the following statements does not describe heterotrimeric g proteins involved in the adenylate cyclase signaling pathway?

a. binding to adenylate cyclase triggers the hydrolysis of PIP2

b. consist of three subunits, Galpha, Gbeta, and Ggamma

c. can function as a mediator to adenylate cyclase activity

d. are anchored to the cytoplasmic side of the membrane

e. activates adenylate cyclase by binding to its C2a subunit

9.) which of the following is not associated with the cAMP binding to cAMP-dependent protein kinase A?

a. cAMP binds to the regulatory subunits

b. catalytic subunits phsphorylate multiple targets with specific serine and threonine residues

c. tetrameric regulatory subunits and catalytic subunits dissociate

d. a total of four cAMP molecules bind to PKA

e. cAMP binds to adenelyate cyclase activating the enzyme

10.) Which statement does not describe a process by which the specificity of aquaporins is ensured?

a. there are carbonyl backbond residues in the channel that hydrogen bond with water

b. the channel contains a negatively charged Asp residue to scavenge protons and H30+

c. the diameter of the channel narrows to 2.8A

d. Arg and His residues in the channel repel protons and H30+

e. electric dipoles of short alpha helices repel protons and H30+

11.) which compound can be cleaved in half to generate a molecule important in vision?

a. arachidonic acid

b. beta-carotene

c. cacitol

d. isoprene

e. tocopherol

12.) Which step is NOT involved in neurotransmitter release at a synapse?

a. creation of a fusion pore

b. hemifusion induced by zipping and lateral tension on the bilayers

c. flippase-mediated moveent of phosphatidylserine from the inner to the outer leaflet

d. v-SNARE binding to t-SNARE

e. pore widening and release of neurotransmitter

13.) Which types of membrane lipids are modified to determine blood type in humans?

a. galactolipids

b. phosphatidylserines

c. plasmalogens

d. sphingomyelins

e. glycosphingolinpids

14.) Peripheral membrane proteins:

a. may have functional units on both sides of the membrane

b. are usually denatured when released from membranes

c. penetrate deeply into the lipid bilayer

d. are generally noncovalently boun to membrane lipids

e. can be released from membranes only by treatment with detergent

Answer 1

Q8. Option a

Q9. Option e

Q10. Option a

Q11. Option b

Q12. Option c

Q13. Option e

Q14. Option d