Lecture 1: Biological Membranes I

Question 1

Describe typical characteristics of a phospholipid in a membrane.

Answer 1

A hydrophilic head on the outside and a hydrophobic tail on the inside

Question 2

What is membrane fluidity?

Answer 2

Membrane fluidity allows:
-fusion of membranes
-diffusion of new lipids and proteins
-diffusion of proteins across membrane in signaling transduction
-proper separation of membranes during cell division

Question 3

What factors regulate membrane fluidity?

Answer 3

-length of fatty acid chain
-degree of saturation of fatty acid chain
-degree of cholesterol between lipids

Question 4

How can proteins associate with a lipid bilayer?

Answer 4

transmembrane, lipid anchored, and peripheral

Question 5

What does a hydrophobicity plots show?

Answer 5

A hydrophobicity plot is a theoretical prediction of hydrophobic domains within a protein that may function as transmembrane domains

Question 6

Hydrophobic region on a hydrophobicity plot is _____

Answer 6

positive

Question 7

Hydrophilic region on a hydrophobicity plot is _____

Answer 7

negative