cell membrane and cholesterol

Question 1

role of lipid bilayer

Answer 1

1. a 2-D liquid that allows lateral movement of proteins and lipids
2. a permeability barrier

Question 2

major class of enzymes:

oxidoreductases

Answer 2

oxidation-reduction

Question 3

NADH and NADPH carrys

Answer 3

electrons

Question 4

coenzyme A carrys

Answer 4

acyl group

Question 5

common covalent modifications of protein activity:

1. myristoylation
2. farnesylation

Answer 5

myristoylation

donor molecule - myristoyl CoA

example - Src

farnesylation

donor molecule - farnesyl pyrophosphate

example - Ras

Question 6

the cell membrane is a composite of

Answer 6

lipids, proteins, and carbohydrates

Question 7

base component is

Answer 7

lipid bilayer

Question 8

carbohydrates decorate ____ and ____ , but are only presented on the:

Answer 8

lipids and proteins

surface, NOT in contact with the cytosol

Question 9

integral membrane proteins span

Answer 9

the entire width of the lipid bilayer

Question 10

membrane proteins have lots of ____ amino acids displayed on their surfaces

this is good when in a ____ environment

bad when the cytoplasm of the cell is ____

some solutions: ____ and ____ ____

Answer 10

hydrophobic

hydrophobic

aqueous

chaperones and co-translational insertion

Question 11

peripheral membrane proteins span

Answer 11

only part of the width of the lipid bilayer

Question 12

peripheral membrane proteins:

membrane anchors are ____

Answer 12

hydrophobic

Question 13

membrane proteins constitute ____ % of the proteome

Answer 13

30

Question 14

functions of membrane proteins

Answer 14

receive external signals

transmit signals into cytoplasm

transmit signals to another cell

allow solutes through the membrane

help to determine membrane thickness and rigidity

Question 15

cell membranes are made up of sev eral different types of structures that allow for their

Answer 15

flexible natures

Question 16

lipids are 2-D fluids, allowing only

Answer 16

lateral movement of components

Question 17

membranes are ____ in composition

Answer 17

asymmetrical

Question 18

in bacteria, ____ of the membrane is determined by ____ ____ composition

Answer 18

rigidity

fatty acid

Question 19

in humans, ____ of the membrane is determined by ____ content

Answer 19

rigidity

cholesterol

Question 20

statins inhibit

Answer 20

the second reaction in the creation of mevalonate

( acetoacetyl-CoA + Acetyl-CoA → mevalonate )

Question 21

vitamin D₃ is derived from

Answer 21

7-dehydrocholesterol

( important intermediate in cholesterol synthesis )

Question 22

lipoproteins transport

Answer 22

TAGs and cholesterol

Question 23

chylomicron:

1. origin
2. destination
3. role

Answer 23

1. intestine
2. adipocytes
3. dietary TAG transport

Question 24

VLDL:

1. origin
2. destination

3.

Answer 24

1. liver
2. adipocytes
3. endogenous TAG transport

Question 25

IDL:

1. origin
2. destination
3. role

Answer 25

1. VLDL
2. liver, LDL
3. intermediate molecule

Question 26

LDL:

1. origin
2. destination
3. role

Answer 26

1. VLDL IDL
2. misc cells
3. cholesterol distribution

Question 27

HDL:

1. origin
2. destination
3. role

Answer 27

1. circulating
2. liver
3. cholesterol collection

Question 28

chylomicron:

major composition

Answer 28

86 % TAG

Question 29

VLDL:

major composition

Answer 29

52 % TAG

Question 30

IDL:

major composition

Answer 30

38 % TAG

30 % cholesterol ester

Question 31

LDL:

major composition

Answer 31

38 % cholesterol ester

Question 32

HDL:

major composition

Answer 32

variable

HDLs make up 33-57 % of proteins in body