Exam 2 Lecture 24 Cellular Membrane Structure

Question 1

what are the 2 basic components of cell membranes

Answer 1

1. mosaic = composite of may types of things: proteins, carbs, lipids
2. carbohydrates decorate lipids and proteins and only found on the surface

Question 2

the base component is the _

Answer 2

lipid (phospholipid) bilayer

Question 3

integral membrane proteins are mostly used for

Answer 3

transport proteins as they span the width of the lipid bilayer

Question 4

membrane proteins have lots of _ displayed on their surfaces

Answer 4

hydrophobic amino acids

Question 5

T/F: hydrophilic where hydrophobic aas are do not have a good connections or interactions

Answer 5

true

Question 6

what are the solutions to integral proteins being exposed to hydrophobic (good) and hydrophilic (bad)

Answer 6

• chaperones

- co-translational insertion (coming right from the ribosome)

Question 7

peripheral membrane proteins require what

Answer 7

require anchor

Question 8

peripheral membranes proteins span only

Answer 8

part of the width of the lipid bilayer

Question 9

membrane anchors are _

Answer 9

hydrophobic

Question 10

membrane proteins help to _

Answer 10

• determine membrane thickness and rigidity
• receive external signals
• transmit signals to another cell
• transmit signals into cytoplasm
• allow solutes through the membrane

Question 11

what makes the membrane flexible?

Answer 11

several different types of structures; everything except nucleic acids (those can only be near)

Question 12

what is lateral movement

Answer 12

rapid diffusion in the same plane

Question 13

what is transverse diffusion

Answer 13

very slow “flip-flopping”

Question 14

membranes are _ in composition and why?

Answer 14

asymmetrical bc we do not flip-flop

Question 15

in bacteria, rigidity of membrane is determined by _ composition

Answer 15

FA composition

Question 16

fluidity vs flexibility aka

Answer 16

saturated vs unstaturated (cis vs trans)

Question 17

in humans, rigidity of the membrane is determined by _

Answer 17

cholesterol content

Question 18

origin of chylomicron (lrg)

Answer 18

intestine

Question 19

destination of chylomicron (lrg)

Answer 19

adipocytes

Question 20

role of chylomicron (lrg)

Answer 20

dietary TAG transport (86%)

Question 21

origin of VLDL

Answer 21

liver

Question 22

destination of VLDL

Answer 22

adipocytes

Question 23

role of VLDL

Answer 23

endogenous TAG transport (stored in body 52%)

Question 24

origin of IDL

Answer 24

VLDL

Question 25

destination of IDL

Answer 25

liver, LDL

Question 26

role of IDL

Answer 26

intermediate molecule (38% TAG, 30% cholesterol ester)

Question 27

origin of LDL (health)

Answer 27

VLDL or IDL

Question 28

destination of LDL (health)

Answer 28

misc cells

Question 29

role of LDL (health)

Answer 29

cholesterol distribution (38% cholesterol ester, 10% TAG)

Question 30

origin of HDL (health)

Answer 30

circulating (5-10% TAG, 19-29% phospholipids, 3-7% free cholesterol, 14-21 cholesterol ester)

Question 31

destination of HDL (health)

Answer 31

liver

Question 32

role of HDL

Answer 32

collecting cholesterol and bring it back to the the liver

Question 33

cholesterol derivative: bile salts are _ detergents

Answer 33

are amphipathic detergents

Question 34

cholesterol derivative: steroid hormones are derivatives of _

Answer 34

pregnenolone

Question 35

cholesterol derivative: cytochrome P450 is part of the_ system

Answer 35

antioxidant sys (saw in PPP)