Liver Flashcards
glycogen in the liver can be made from
glucose-6-P: injested, GNG, blood
fate of pyruvate:
- made from glucose-6-P or from lactate from muscle
- pyr. carbox -> OAC -> TCA
- pyr. dehydr. -> AcCoA -> TCA
livers role in FA synth
- glucose-6-P from liver into PPP -> NADPH+H⁺ -> FA synth
- TCA -> citrate -> AcCoA (with NADPH+H⁺ from PPP) -> FA synth
PPP role
NADPH+H⁺ : FA synth
ribose-5-P: nucleotide
amino acid fate in liver
protein synthesis
GNG - transamination
NH3 - deamination
(or no reaction in liver to enter other tissues)
NH3 fate
from deamination of aa
- react with glu to make glutamine -> urine
- enter urea cycle to make urea -> urine
(ammonia can also be reabsorbed from urine to enter liver)
fate of FA in liver
(from chylomicron, lipoprotein, or synthesized from AcCoA)
- triacylglycerol synth to make lipoprotein (VLDL, LDL) or fat
- beta-oxidation to make AcCoA
fate of AcCoA in FA metabolism
- enter TCA
- ketogenesis -> extrahepatic organs
- cholesterol synth (in cytoplasm)
secretion of liver
via bile
- bile acids -> salts
- bile pigments -> biliverdin, bilirubin -> conjugation
- cholesterol -> esterified or free form
synthesis using NH3 in liver
(detoxification by synthesis)
- urea from NH3
- glutamine from glutamate and NH3
- uric acid/allantoine (purine nucleotides)
detoxification using hydroxylation
- steroid hydroxylase and certain drugs to add -OH to incr. water solubiity
- CYP 450
steroid hydroxylase
synthesis and elimination of bile salts
Cytochrome 450 detoxification
xenobiotics: not naturally produced or expected to be present within the organism —> CYP450 has heme as cofactor; metabolize potentially toxic compounds, including drugs and products of endogenous metabolism such as bilirubin, principally in the liver.
ethanol oxidation as detoxification
creating acetyl-CoA from ethanol
detoxification by reduction of insulin in the liver
breaking the disulphide bonds
- by reducing -S=S- to -SH SH-
