lipid metabolism

Question 1

how do lipids cross the cell membrane

Answer 1

through the fatty acyl carnitine shuttle

Question 2

can FA be used for gluconeogenesis

Answer 2

no

Question 3

where does beta oxidation occur

Answer 3

in the mitochondrial matrix

Question 4

what are the products of one cycle of beta oxidation

Answer 4

1 acetyl Co A
1 FADH
1 NADH + H
1 fatty acyl CoA - shortened by 2 carbon atoms

Question 5

what is the equation o the number of oxidation cycles for an even numbered saturated fat

Answer 5

(C/2) - 1

Question 6

where and when are ketone bodies formed

Answer 6

in the liver mitochondria under fasting conditions

Question 7

how are ketone bodies made

Answer 7

from acetyl Co A as a by product of beta oxidation

diffuse into the bloodstream

Question 8

what do ketone bodies do in the brain

Answer 8

energy production and neurotransmitter synthesis

Question 9

are ketone bodies toxic to peripheral tissues

Answer 9

no

Question 10

what can ketone bodies lead to

Answer 10

ketoacidosis

Question 11

what does glucose generate

Answer 11

acetyl Co A

Question 12

what is acetyl Co A converted to

Answer 12

manonyl CO A

Question 13

what is malonyl CO A

Answer 13

fatty acid synthesis precurose

Question 14

what enzyme catalyses acetyl Co A to malonyl CoA

Answer 14

acetyl Co A carboxylase

Question 15

what is Acetyl-CoA Carboxylase activity regulated by

Answer 15

nutrient and energy status

Question 16

where are fatty acids made

Answer 16

cytoplasm

Question 17

where are fatty acids degraded

Answer 17

matrix of mitochondria

Question 18

what stimulate Acetyl-CoA carboxylase

Answer 18

citrate and insulin

Question 19

what inhibit Acetyl-CoA carboxylase

Answer 19

AMP, glucagon, epinephrine palmitoyl Co A

Question 20

how does citrate stimulate

Answer 20

allosterically

Question 21

when is palmotoyl Co A abundant

Answer 21

when fatty acids in excess

Question 22

what does epinephrine signal

Answer 22

requirement for energy

Question 23

is fatty acid synthesis oxidative or reductive

Answer 23

reductive

Question 24

what does fatty acid synthesis require

Answer 24

NADPH

Question 25

what catalyses glycogen to glucose 1 phosphate

Answer 25

glycogen phosphorylase

Question 26

what catalyses glucose 1 phosphate to glucose 6 phosphate

Answer 26

phosphoglucomutase

Question 27

what does gluconeogenesis proceed via the syntehsis of

Answer 27

oxaloacetate

Question 28

what is glycogenin

Answer 28

protein in centre of glycogen polymer - important as glycogen synthase can only ass glucose to existing glycogen chain

Question 29

where are amino acids oxidised

Answer 29

TCA cycle

Question 30

what are amino acids precursors for

Answer 30

gluconeogenesis

Question 31

where does glycolysis occur

Answer 31

cytoplasm

Question 32

what is the P/O ratio

Answer 32

a measure of the ATP molecules formed per O atom reduced

Question 33

what has a more lower redox potential - NADH or FADH 2

Answer 33

FADH (less likely to donate electron)

Question 34

what does a negative redox potential mean

Answer 34

lower affinity for electrons than H - more likely to donate