BIOL1007 - Structure and function of biological membrane (1)

Question 1

percentage of genome coding for membrane proteins

Answer 1

25%

Question 2

where is cell membrane found in

Answer 2

every cell and eukaryotic organelles

able to see detail through electron microscopy

Question 3

Cl- channel role of membrane proteins in disease

Answer 3

cystic fibrosis and Becker’s myotonia

Question 4

Ca+ channel role of membrane proteins in disease

Answer 4

malignant hyperthermia and Darier disease

Question 5

K+ channel role

Answer 5

long - QT syndrome

Question 6

acetylcholine receptor role

Answer 6

congenital myasthenic syndrome

Question 7

2 features of membrane

Answer 7

membrane protein and lipids

Question 8

majority compose of protein

Answer 8

inner mitochondrial, nuclear, rER, plasma

Question 9

majority compose of lipids

Answer 9

mylin

Question 10

almost similar amount of protein and lipids

Answer 10

erythrocyte, outer membrane and Golgi

Question 11

3 major classes in lipid bilayer

Answer 11

phospholipids, sphingolipid, sterol

Question 12

phospholipids

Answer 12

2FA + glycerol + phosphate and OH

usually with head group attach to choline

Question 13

neutral head groups

Answer 13

ethanolamine and choline

Question 14

negative head groups

Answer 14

serine, glycerol, inositol

Question 15

sphingolipid

Answer 15

sphingosine - has no glycerol
sphingomyelin - chain attached to amide
major component of neuronal membrane

Question 16

sterol - cholesterol

Answer 16

mainly in eukaryotic membrane

Question 17

amphiphatic

Answer 17

has hydrophilic head and hydrophobic

Question 18

spontaneous form in aquaeous

Answer 18

minimises DG of system

hydrophobic interact with OH hydrophobic sites - minimises entropic cost - Hydrophobic effect

Question 19

inositol

Answer 19

cyclic and same behaviour as others

rest of OH groups - used for signalling

Question 20

sphingolipids location

Answer 20

in plasma membrane

Question 21

liquid phase - membrane

Answer 21

membrane contain large amounts of lipid with acyl chain

Question 22

cis phospholipids

Answer 22

prevent close packing of acyl chains - mobile

Question 23

liquid crystalline phase

Answer 23

lipids move around in plane of bilayer

require fluid environment

Question 24

saturated lipid

Answer 24

compact together - reduction - rigid bilayer

Question 25

dynamic - lateral diffusion

Answer 25

very rapid exchange and movement in plane - D = 10(-9)cm(-2)s(-1)

Question 26

lipid flip flop

Answer 26

energetically unfavourable - long time taken - days or hours
enhanced by membrane fusion/ enzymes(flippase)
preserves membrane asymmetry

Question 27

fluidity in low temperature

Answer 27

liquid crystalline turns into gel phase - acyl chain - frozen

Question 28

molecules in fluidity

Answer 28

able to move - carry substrates between enzymes and mediate signalling events