L12: Gluneogenesis Flashcards
1
Q
where does gluconeogenesis occur?
A
- in mitochondrion and cytoplasm
- generally occurs in the liver under fasting conditions
2
Q
why use gluconeogenesis?
A
- glucose levels needs to be maintained since the brain uses glucose for fuel
- mostly used by brain, muscle, and red blood cells
3
Q
Noncarbohydrate precursors that generate pyruvate
A
- lactate
- amino acids
- glycerol - breakdown of fat
4
Q
fed state:
A
- dietary glucose is exhausted quickly
- just after a meal, the glucose you consumed is depleted after a few hours
5
Q
fasting state
A
- breakdown of glycogen to glucose
- lactate, amino acids, and glycerol will come in and help generate glucose
- when you need a boost of energy
- goes away after about a day
6
Q
starved state
A
- gluconeogenesis provides a relatively constant level of glucose
- provided by the liver
7
Q
where does glycerol come from?
A
- released from fat stores (adipose cells) due to triglyceride breakdown
8
Q
where does propionate come from?
A
- odd-chain fatty acids
- produce propiony-CoA
9
Q
propionyl-CoA track
A
- propionyl CoA -> succinyl CoA -> TCA cycle -> oxaloacetate
10
Q
which is the major gluconeogenic amino acid?
A
- alanine
11
Q
lactate comes from?
A
- muscle tissues undergoing anaerobic glycolysis
- through circulation and enters liver
12
Q
lactate to pyruvate
A
- requires lactate dehydrogenase
- requires NAD+
13
Q
When NADH levels are high?
A
- reaction goes toward lactate
- inhibits gluconeogenesis
14
Q
alanine to pyruvate
A
- via alanine aminotransferase
15
Q
glycerol to DHAP
A
- glycerol -> glycerol-3-phosphate by glycerol kinase
- glycerol-3-phosphate -> DHAP by glycerol-3-phosphate dehydrogenase
