Liver Biochemistry

Question 1

Cell in the space of disse that stores vitamin A

Answer 1

Stellate, also store lipids

lose vit a stores when activated

Question 2

Cells that are natural killers in space of disse to protect against viruses

Answer 2

Pit cells

Question 3

Chemical reactions in Phase 1 of detoxification of xenobiotics

Answer 3

reduction, oxidation, hydroxylation, hydrolysis

this increases solubility and gets active sites for adding something else (phase 2)

Question 4

Chemical reactions in Phase 2 of detoxification

Answer 4

Conjugation, sufation, methylation, gluconuration. increases solubility

Question 5

cytochome p450 use what cofactors to do shit

Answer 5

NADPH and O2

Question 6

What makes the p450 enzymes be expressed?

Answer 6

their substrates

Question 7

What would cause vinyl chloride to cause angiosarcoma?

Answer 7

the CYP2E1 or Glutathione cannot keep up with the amount of exposure.
(phase 2 reactions can’t keep up)

Question 8

what give the sulfur in phase II reactions?

Answer 8

PAPS

phosphoadenosine phosphosulfate

Question 9

Why shouldn’t I butt chug a four loko and eat an acetomenophen sandwich?

Answer 9

Ethanol induces expression of CYP2E1, which metabolizes acetominophen to NAPQI, which is toxic.

Question 10

What’s the mechanism of ethanol toxicity?

Answer 10

acetaldehyde activates the Kupffer cells. They secrete TGF-Beta that turns the stellate cells into collagen forming cells –> fibrosis.

Question 11

what enzyme take NH4 off of glutamine when it gets to the liver

Answer 11

Glutaminase

Question 12

After glutaminase, what happens to NH4?

Answer 12

Carbamoyl Phosphate synthase 1 (CPS1) –> Carbamoyl Phosphate –> then ornithine

Question 13

What if CSP1 is saturated and can’t fix ammonia anymore?

Answer 13

We put the ammonia back onto glutamine so it’s not just floating around

Question 14

What happens to beta-cat if WNT isn’t around?

Answer 14

It gets phosphorylated by APC and degraded in the proteosome

Question 15

Why is there a high WNT expression near the central vein in a liver lobule?

Answer 15

WNT causes glutamine synthase to be made. So far away from the center, free ammonia can be used in the urea cycle

Question 16

Ketones are made from what?

Answer 16

Fatty acids –> acetyl CoA –> acetoacetate –> beta- hydroxybutyrate

Question 17

What are the products of the pentose phosphate pathways used for?

Answer 17

NADPH –> cholesterol synthesis, also detox of xenobiotics (cyto 450)
Ribose –> nucleotide synthesis

Question 18

Sugars are attached to what molecule to make glycoproiens? What is it made of?
btw, this happens in the ER of hepatocytes

Answer 18

Dilochol

from cholesterol

Question 19

what enzyme is elevated in bile duct blockage?

Answer 19

alkaline phosphatase

Question 20

Deceased Albumin can be caused by acute or chronic liver failure?

Answer 20

Chronic, because it has a long half life

Question 21

Why can a long PTT be from liver damage

Answer 21

bc that’s where the clotting factors are made you dummy!

Question 22

Grapefruit juice inhibits what enzyme.

What drug does that normally metabolize

Answer 22

Cyp3A4

statins

Question 23

Phosphoglucomutase 1 catalyzes what reaction?

if you have a mutation in it, what symptom is present

Answer 23

Glucose 1-P to glucose 6-p
goes bothdirrections depending on [ ]’s

resting hypoglycemia

Question 24

What amino acids help get rid of Nitrogen?

Answer 24

Alanine - from other AA’s

Glutamine - can fix free ammonium