Chapter 12: Lipids and Membranes

Question 1

Flippase

Answer 1

Aid in the movement of phospholipid molecules between the two leaflets that compose a cell’s membrane

Move lipids from the exoplasmic to the cytosolic face utilizing ATP

Question 2

Floppase

Answer 2

Aid in the movement of phospholipid molecules between the two leaflets that compose a cell’s membrane

Move lipids from the cytosolic face to the exoplasmic utilizing ATP

Question 3

Scramblase

Answer 3

Aid in the movement of phospholipid molecules between the two leaflets that compose a cell’s membrane WITHOUT the input of ATP

Bidirectional

Question 4

Glycolipids

Answer 4

Carbohydrate-containing lipids derived from sphingosine

The carbohydrate is linked to the primary alcohol of sphingosine

Question 5

Cholesterol

Answer 5

A steroid that is modified on one end by the attachment of a fatty acid chain and at the other end by a hydroxyl group

In membranes, the hydroxyl group interacts with phospholipid heads

Question 6

Molecules that have both hydrophobic and hydrophilic properties

Answer 6

Amphipathic

Question 7

Integral membrane proteins

Answer 7

Largely nonpolar

Span the lipid bilayer

(a & b)

Question 8

Peripheral membrane proteins

Answer 8

Primarily bound by electrostatic and hydrogen-bonding

Largely polar external residues

(c & d)

Question 9

Hydrophobic attachment

Answer 9

Bound by a fatty acid to the membrane

(e)