lecture 34 - alcohol metabolism Flashcards
what is ethanol an agonist of
the GABAA receptor
how does alcohol effect the nervous system
by binding to the GABAA receptor
what is the GABAA receptor
membrane bound ligand gated chloride channel
what happens when the GABAA is activated
selectively conducts Cl- ions causing an inhibitory effect on neurotransmission by reducing the chance of a successful action potential
= more chloride molecules flow through the membrane
- damps down responses to other stimuli
how is ethanol converted to acetaldehyde
alcohol dehydrogenase
- NAD+ is reduced
- NADH can the be oxidised in the mitochondria
what is acetaldehyde
it is a toxin, build up of this causes the feelings of a hangover
what happens to acetaldehyde in the body
rapidly removed from the body as it is a toxin
- aldehyde dehydrogenase reduces NAD+ to convert acetaldehyde to acetate
- NADH can be sent for oxidative phosphorylation
what are the forms of alcohol dehydrogenase
mitochondrial = mostly
also
cytosolic
how can aldehyde dehydrogenase be inhibited clinically
by a drug called Antabuse = aldehyde dehydrogenase inhibited so causes build up of acetaldehyde which makes the individual feel unwell
- good for treating alcohol issues
what converts acetate into Acetyl CoA and what does this mean
Acetyl CoA synthetase
does alcohol metabolism have a negative feedback loop
no, unlike other pathways alcohol metabolism does not have a negative feedback loop = so it rapidly produces Acetyl CoA
what effects does ethanol metabolism have on other metabolic process in the liver
slows the :
- citric acid cycle
- electron transport chain
- pyruvate dehydrogenase
- glycolysis (phosphofructinase)
- fatty acid oxidation
ethanol metabolism causes fatty acids to be oxidised to TAG which means …
increased triacylglycerol in the liver
- can also result in hypercholesterolaemia and hypertriacyglycerolaemia
ethanol metabolism causes pyruvate to converted to lactate which means …
decreased pH = lactate is acidic
ethanol metabolism inhibits glucogenesis which means
- can cause low blood glucose
- can cause coma
