Compare and contrast the structural features of the ion carrier valinomycin with those of a channel former like gramicidin. How does the structural information help explain the mechanism by which these molecules conduct ions across membrane bilayers?

Zohpius

April 12, 2023

CH 462/562 Biochemistry
Discussion Questions Paper #1
Upload to Canvas by 11:59 PM Wednesday April 12, 2023
Your answers should be concise but not too brief: no more than two pages for the entire assignment . To have a chance to get full credit on the assignment you must use a word processor. Hand-written answers will only receive minimal credit.

Kranse et. al., (1971) Freezing and Melting of Lipid Bilayers and the Mode of Action of Nonactin.

This classic paper compares the membrane conductance of two small molecule ion carriers with a small molecule ion channel former across bilayers at different temperatures. You should review the structure of the -helix on pp 135-137 of your textbook to answer question #2 below, and read about membrane proteins and the structure of valinomycin on pp 295-297 of your textbook.

Background Questions

1. Compare and contrast the structural features of the ion carrier valinomyc in with those of a channel former like gramicidin. How does the structural information help explain the mechanism by which these molecules conduct ions across membrane bilayers?