Chapter 11

Question 1

are lipid molecules soluble in water?

Answer 1

no

Question 2

what do lipid molecules dissolve in?

Answer 2

organic solvents (benzene)

Question 3

structure of a phospholipid

Answer 3

hydrophilic head
hydrophobic tail

Question 4

parts of a phospholipid

Answer 4

choline
phosphate
glycerol
hydrocarbon tails

Question 5

phospholipids are _____

Answer 5

amphipathic

Question 6

what form of a phospholipid bilayer is energetically favorable

Answer 6

formation of a sealed compartment shields hydrophobic tails from water

Question 7

what properties of hydrocarbon tails make them more fluid

Answer 7

shorter tails
more unsaturated tails

Question 8

unsaturated

Answer 8

organic molecule that contains one or more double or triple bonds between its carbon atoms

Question 8

what properties of hydrocarbon tails makes them less fluid

Answer 8

longer tails
more saturated tails

Question 8

saturated

Answer 8

organic molecule that contains a full complements of hydrogen

Question 9

cholesterol

Answer 9

short, rigid lipid molecule present in large amounts in the plasma membrane of animal cells, where it makes the lipid bilayer less flexible

Question 9

new phospholipids are manufactured by enzymes bound to the __________

Answer 9

cytosolic surface of the endoplasmic reticulum

Question 10

function of scramblase

Answer 10

transporter protein that randomly removes selected phospholipids from one half of the lipid bilayer and inserts them in the other

Question 11

function of flippases

Answer 11

use the energy of ATP hydrolysis to transfer specific phospholipids from one side of the bilayer to the other

Question 12

what initiates and maintains the asymmetric arrangement of phospholipids

Answer 12

flippases

Question 13

types of plasma membrane proteins

Answer 13

transporters
ion channels
anchors
receptors
enzymes

Question 14

what can disrupt the lipid bilayer

Answer 14

detergents
disrupting hydrophobic associations

Question 15

a transmembrane polypeptide chain usually crosses the lipid bilayer as a _____ with the ______ amino acid side chain on the outside

Answer 15

alpha helix
hydrophobic

Question 16

cell cortex

Answer 16

specialized layer of cytoplasm on the inner face of the plasma membrane
in animal cells, it is rich in actin filaments that govern the cell shape and drive cell movement

Question 17

membrane domain

Answer 17

functionally and structurally specialized region in the membrane of a cell or organelle

Question 18

glycocalyx

Answer 18

protective layer of carbohydrates on the outside surface of the plasma membrane formed by the sugar residues of membrane glycoproteins, proteoglycans, and glycolipids

Question 19

role of cell-surface carbohydrates in cell-cell recognition and adhesion

Answer 19

lectins (transmembrane proteins) bind to particular oligosaccharide side chains