N: ALCO: metabolism Flashcards
where is alcohol absorbed?
small intestine
what enzyme metabolises alcohol?
dehydrogenase
what is different about men and women dehydrogenase levels?
men have more dehydrogenase in stomach than women
what is the primary alcohol metabolism site and how is alcohol transported there?
liver is the primary alcohol metabolism site
-> liver cells contain dehydrogenase
alcohol travels there through the portal vein system
what happens to the alcohol not metabolised?
it passes around the body affecting every organ - including brain
but eventually liver metabolism & kidney excretion clears alco from body
how much ethanol can liver process per hour?
15g /HOUR
describe metabolism of alcohol:
alcohol(ethanol) OXIDATION
- > acetaldehyde via. alcohol dehydrogenase
- > acetate via. acetaldehyde dehydrogenase
- > acetyl-CoA (made by acetate + CoA)
- > TCA or fatty acid (can be used to provide energy via TCA or produce fatty acids for storage as fat when energy is plentiful)
in terms of high energy intermediates what does high alcohol consumption do?
NAD+ depletion
NADH accumulation
outline why excess alcohol is mostly converted into fat rather than providing its energy for ATP production?
- > NAD+ depleted (due to high alco)
- > NAD+ vital to drive TCA cycle, so cannot work with depleted levels
- > so acetyl-CoA produced from alcohol metabolism CANNOT enter TCA cycle and is converted into fatty acids for storage as fat
- > this can lead to “fatty liver” which is a irreversible condition
4 main effects of alcohol on the brain:
1) sedates frontal lobe
2) sedates speech and vision in midbrain
3) voluntary muscle control reduced - cerebellum
4) respiratory and heart rate - pons & medulla => unconsciousness
importance of unconsciousness when drinking
unconsciousness prevents you drinking to a level which would supress deep brain centres
what vitamins and minerals are heavy drinkers often low in?
1) vitamin B
2) folate
3) thiamine
drinking reduces the absorption of these
