Chapter 10: Membrane Structure

Question 1

Black membrane

Answer 1

Artificial planar lipid bilayer formed across a hole in a partition between two compartments

Question 2

Liposome

Answer 2

Artificial phospholipid bilayer vesicle formed from an aqueous suspension of phospholipid molecules

Question 3

Hydrophobic

Answer 3

Describes a nonpolar molecule or part of a molecule that cannot form energetically favorable interactions with water molecules and therefore does not dissolve in water

Question 4

Lipid raft

Answer 4

Small region of the plasma membrane enriched in sphingolipids and cholesterol

Question 5

Ganglioside

Answer 5

Any glycolipid having one or more sialic acid residues in its structure; especially abundant in the plasma membrane of nerve cells

Question 6

Amphiphilic

Answer 6

Having both hydrophobic and hydrophilic regions, as in a phospholipid or a detergent molecule

Question 7

Phospholipid

Answer 7

THe main type of phospholipid in animal cell membranes, with two fatty acids and a polar head group attached to a three carbon glycerol backbone

Question 8

Cholesterol

Answer 8

Lipid molecule with a characteristic 4 rind steroid structure that is an important component of the plasma membranes of animal cells

Question 9

Glycolipid

Answer 9

Lipid molecule with a sugar residue or oligosaccharide attached

Question 10

Hydrophilic

Answer 10

Dissolving readily in water

Question 11

Lipid bilayer

Answer 11

THin double sheet of phospholipid molecules that forms the core structure of all cell membranes. THe two layers of lipid molecules are packed with their hydrophobic tails pointing inward and their hydrophilic heads outward, exposed to water.

Question 12

Phosphoglyceride

Answer 12

Phospholipid derived from glycerol, abundant in membranes

Question 13

Plasma membrane

Answer 13

The membrane that surrounds a living cell

Question 14

Lipid droplets

Answer 14

a store of excess lipids in cells, from where they can be retrieved as building blocks for membrane synthesis or as a food source.

Question 15

Lectin

Answer 15

Protein that binds tightly to a specific sugar

Question 16

Carbohydrate layer

Answer 16

The outer coat of a eucaryotic cell, composed of oligosaccharides linked to intrinsic plasma membrane glycoproteins and glycolipids, as well as proteins that have been secreted and reabsorbed onto the cell surface

Question 17

Spectrin

Answer 17

Abundant protein associated with the cytosolic side of the plasma membrane in red blood cells, forming a rigid network that supports the membrane

Question 18

Multipass transmembrane protein

Answer 18

Protein whose polypeptide chain crosses the lipid bilayer more than once

Question 19

Bacteriorhodopsin

Answer 19

Pigmented protein found in the plasma membrane of Halobacterium halobium, where it pumps protons out of the cell in response to light

Question 20

Cortex

Answer 20

The complicated cytoskeletal network in the cytosol just beneath the plasma membrane

Question 21

Peripheral membrane protein

Answer 21

Protein that is attached to one face of a membrane by a noncovalent interactions with other membrane proteins and can be removed by relatively gentle treatments that leave the bilayer intact

Question 22

GPI anchor

Answer 22

Type of lipid linkage, formed as a proteins pass through the endoplasmic reticulum, by which proteins are attached to the noncytosolic surface of the membrane

Question 23

Integral membrane proteins

Answer 23

Transmembrane proteins and many proteins held in the bilayer by lipid groups or hydrophobic polypeptide regions that insert into the hydrophobic core of the lipid bilayer

Question 24

Single pass transmembrane protein

Answer 24

Polypeptide chain passes through the plasma membrane only once

Question 25

Detergents

Answer 25

Small amphiphilic molecules that are able to remove peripheral membrane proteins.