Liver Biochemistry (Quiz 3) Flashcards
in the fed state, which nutrients are in excess
how many hours after a meal classifies the fed state
- glucose
- acetyl CoA
- amino acids
- 2-4
what does the liver use glucose for in the fed state
- use glucose for own energy
- make NADPH
- store as glycogen
what does the liver use acetyl CoA for in the fed state
- supply liver ATP
- make fatty acids and triacylglyercides
what does the liver use amino acids for in the fed state
- synthesize liver proteins
- use C-O backbone to make glucose and fats
what does the liver use for energy in the fasting state
- fatty acids from beta oxidation
what does the liver use glycogen for in the fasting state
- provide glucose to brain and RBCs
what does the muscle use for energy in the fasting state
- ketones
after feeding ________is utilized and is depleted after about 4 hours
- dietary glucose
dietary glucose is followed by breakdown of _______ into _________ by the liver from 3-20 hours after a meal
- breakdown of glycogen into glucose
as glycogen breakdown begins to subside, what provides a steady amount of glucose
- gluconeogenesis
as blood glucose declines after about 2 days of starvation, what is produced for energy
- ketone bodies
glucose levels ________ during the first days of starvation then ________ over the next few days
- decline during the first days of starvation
- stabilize over the next few days
what occurs to detoxify and eliminate compounds
- biotransformation reactions
what are phase I reactions
- oxidation
- hydroxylation
- reduction
- hydrolysis
what are phase II reactions
- conjugation
- sulfation
- methylation
- glutathione addition
- glucuroindation
what is the purpose of biotransformation reactions
- helps make compounds more soluble so they can be excreted more easily
low levels of ethanol are biotransferred by which process
- alcohol dehydrogenase
high levels of ethanol are biotransferred by which process
- MEOS
alcohol dehydrogenase pathway
ethanol -> acetaldehyde (alcohol dehydrogenase
acetaldehyde -> acetate (acetaldehyde dehydrogenase)
MEOS pathway
- cytochrome P450 converts ethanol to acetaldehyde
what is the problem with acetaldehyde
- it is toxic
amine groups from degraded proteins are used to make what
what happens next
- glutamate
- glutamate -> ammonia and alpha ketoglutarate (glutamate dehydrogenase)
purpose of carbomyl phosphate synthetase
ammonia + bicarbonate + ATP -> carbamoyl phosphate
- enters Urea cycle
each turn of the urea cycle sequesters two _______ into ______ which is eliminated in the _______
- two amine groups
- into urea
- eliminated in the urine
carbon and oxygen skeletons of amino acids converted to
- glucose
- triacylglycerols
- acetyl CoA
what is the primary site of the urea cycle in adults
- the liver
gluconeogenesis is initiated by a ______ in insulin signaling and a ________ in glucagon signaling
- decrease in insulin signaling
- increase in glucagon signaling
