Liver

Question 1

glycogen in the liver can be made from

Answer 1

glucose-6-P: injested, GNG, blood

Question 2

fate of pyruvate:

Answer 2

• made from glucose-6-P or from lactate from muscle
• pyr. carbox -> OAC -> TCA
• pyr. dehydr. -> AcCoA -> TCA

Question 3

livers role in FA synth

Answer 3

• glucose-6-P from liver into PPP -> NADPH+H⁺ -> FA synth

- TCA -> citrate -> AcCoA (with NADPH+H⁺ from PPP) -> FA synth

Question 4

PPP role

Answer 4

NADPH+H⁺ : FA synth

ribose-5-P: nucleotide

Question 5

amino acid fate in liver

Answer 5

protein synthesis
GNG - transamination
NH3 - deamination
(or no reaction in liver to enter other tissues)

Question 6

NH3 fate

Answer 6

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)

Question 7

fate of FA in liver

Answer 7

(from chylomicron, lipoprotein, or synthesized from AcCoA)

• triacylglycerol synth to make lipoprotein (VLDL, LDL) or fat
• beta-oxidation to make AcCoA

Question 8

fate of AcCoA in FA metabolism

Answer 8

• enter TCA
• ketogenesis -> extrahepatic organs
• cholesterol synth (in cytoplasm)

Question 9

secretion of liver

Answer 9

via bile

• bile acids -> salts
• bile pigments -> biliverdin, bilirubin -> conjugation
• cholesterol -> esterified or free form

Question 10

synthesis using NH3 in liver

Answer 10

(detoxification by synthesis)

• urea from NH3
• glutamine from glutamate and NH3
• uric acid/allantoine (purine nucleotides)

Question 11

detoxification using hydroxylation

Answer 11

• steroid hydroxylase and certain drugs to add -OH to incr. water solubiity
• CYP 450

Question 12

steroid hydroxylase

Answer 12

synthesis and elimination of bile salts

Question 13

Cytochrome 450 detoxification

Answer 13

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.

Question 14

ethanol oxidation as detoxification

Answer 14

creating acetyl-CoA from ethanol

Question 15

detoxification by reduction of insulin in the liver

Answer 15

breaking the disulphide bonds

- by reducing -S=S- to -SH SH-

Question 16

detoxification by hydrolysis

Answer 16

hydrolysis of digitalis alkaloids -> degredation

Question 17

general: conjugation in the liver

Answer 17

to make xenobiotics, hormones, drugs/medicine able to exrete out of body through urine/faeces

Question 18

what can be conjugated with what in liver

Answer 18

1. glucoronic acid - bile acids, bile pigments, antibiotics
2. sulphuric acid - steroid hormones, e.g tryptophan in horse make indol=toxic
3. amino acids - benzoic acid (bile acid + gly/taurine)