lecture 36 - starvation

Question 1

how much glucose does the brain need per day

Answer 1

120 grams

Question 2

what hormone is produced by the pancreas when blood glucose drops

Answer 2

glucagon

Question 3

how much glucose does the liver provide and how does it do this

Answer 3

90-120 grams = enough energy for the brain for one day

the hormone glucagon stimulates glycogen phosphorylase to mobilises glycogen back to glucose

Question 4

what is glycogenolysis

Answer 4

glucose molecules are converted to glycogen

Question 5

what is glucogenesis and where does it mainly occur

Answer 5

occurs mainly in the liver and is the synthesis of glucose from ……

• lactate from muscle glycogen
• alanine from muscle protein
• glycerol from adipose tissue

Question 6

what stimulates glucogenesis

Answer 6

glucagon

Question 7

what provides the energy for glucogenesis

Answer 7

fatty acid oxidation

Question 8

fatty acids can not be used to make glucose but they can used for …..

Answer 8

via B oxidation provide ATP and NADH for glucogenesis

Question 9

can proteins make glucose

Answer 9

yes some can be degraded to amino acids to make glucose

Question 10

what does loss of too much protein cause

Answer 10

loss of too much protein causes structural and functional damage

Question 11

where and what are ketone bodies synthesised from

Answer 11

synthesised in the liver from fatty acids

• via B oxidation and ketogenesis

Question 12

when are ketone bodies used

Answer 12

used by starving brain as energy source

Question 13

what are the metabolic adaptations to starvation

Answer 13

• fatty acids used as fuel for all aerobic tissue except the brain
• ketone bodies used by the brain
• therefore the brain needs less glucose
• therefore muscle degradation can slow down
• therefore body can survive longer