Metabolism 83-89 Flashcards Preview

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Flashcards in Metabolism 83-89 Deck (57):
1

Ethanol metabolism limiting reagent

NAD+
Increased NADH/NAD ratio in the liver causes
Pyruvate-->lactate (lactic acidosis)
Oxaloacetate-->gluconeogenesis (fasting hypoglycemia)
Dihydroxyacetone phosphate --> G3P (hepato steatosis)
Changes seen in CHRONIC ALCOHOLISM

2

Fomepizole

Inhibits alcohol dehydrogenase
Antidote for methanol or ethylene glycol poisoning

3

Disulfiram

Inhibits acetaldehyde dehydrogenase
Accumulation of acetaldehyde

4

Metabolic processes in mitochondria

Fatty acid oxidation
Acetyl - CoA production
TCA cycle
Oxidative phosphorylation
Ketogenesis

5

Metabolic processes in cytoplasm

Glycolysis
HMP shunt
Steroids
Proteins (ribosomes, RER)
Fatty acids
Cholesterol
Nucleotides

6

Mitochondrial and cytoplasmic metabolic processes

Heme synthesis
Urea cycle
Gluconeogenesis
"HUGs take two"

7

RD enzyme of glycolysis

Phosphofructokinase 1

8

Regulation of PFK 1

Increased by AMP, fructose 2,6 bisphosphate
Inhibited by ATP and citrate

9

RD enzyme of gluconeogenesis

Fructose 1,6 bisphosphatase

10

Regulation of fructose 1,6 bisphosphatase

Inhibited by AMP and fructose 2, 6 bisphosphate

11

RD enzyme of TCA cycle

Isocitrate dehydrogenase

12

Regulation of isocitrate dehydrogenase

Increased by ADP
Inhibited by ATP, NADH

13

Ethanol metabolism pathway

Ethanol --etoh dehydrogenase-->acetaldehyde --acetaldehyde dehydrogenase-->acetate

14

RD enzyme of glycogenesis

Glycogen synthase

15

Regulation of glycogen synthase

Increased by G6P, insulin, cortisol
Inhibited by epinephrine and glucagon

16

Glycogenolysis

Glycogen phosphorylase

17

Regulation of glycogen phosphorylase

Increased by epinephrine, glucagon, AMP
Inhibited by G6P, insulin and ATP

18

HMP shunt rate limiting enzyme

Glucose 6 phosphate dehydrogenase

19

Glucose 6 phosphate dehydrogenase regulators

Increased by NADP
Inhibited by NADPH

20

De novo pyrimidine synthesis rate determining enzyme

Carbamoyle phosphate synthetase II

21

Carbamoyle phosphate synthetase II regulators

Increased by PRPP, ATP
Inhibited by UTP

22

De novo purine synthesis rate limiting enzyme

Glutamine PRPP amidotransferase

23

Gluamine PRPP amidotransferase regulators

Inhibited by AMP, IMP and GMP

24

Urea cycle rate limiting enzyme

Carbamoyle phosphate synthetase II

25

Carbamoyle phosphate synthetase I regulators

Increased by N-acetylglutamate

26

Fatty acid synthesis rate limiting enzyme

Acetyl CoA carboxylase

27

Acetyl CoA carboxylase regulators

Increased by insulin and citrate
Inhibited by glucagon and palmitoyl-CoA

28

Fatty acid oxidation rate limiting enzyme

Carnitine acetyltransferase I

29

Carnitine acetyltransferase I regulators

Inhibited by Malonyl CoA

30

Ketogenesis rate limiting enzyme

HMG CoA SYNTHASE

31

Cholesterol synthesis rate limiting enzyme

HMG CoA REDUCTASE

32

HMG CoA REDUCTASE regulators

Increased by insulin and thyroxine
Inhibited by glucagon and cholesterol

33

What chemical causes glycolysis to produce zero net ATP?

Arsenic

34

Processes that NAPH are used in

Anabolic
Respiratory burst
P450 system
Glutathione reductase

35

Hexokinase or glucokinase catalyze?

Glucose --> G6P (1st committed step of glycolysis/glycogen synthesis)

36

Hexokinase vs. glucokinase

Hexokinase
Most tissues, low Km, low Vmax, NOT induced by insulin, Feedback inhibited by G6P, gene mutation associated with diabetes of the young? NO
Glucokinase
Liver and pancreas beta cells, high Km and High Vmax, INDUCED BY INSULIN, not inhibited by G6P, Gene mutation is associated with maturity onset diabetes of the young

37

Glycolysis steps that require ATP and produce ATP

Require ATP: Hexokinase/glucokinase and PFK1
Produce ATP: phosphoglycerate kinase, Pyruvate kinase (formation of 3 PG and Pyruvate)

38

PFK1 induction by fructose 2,6 bisphosphate

Increased PFK2 activity in fed state (increased insulin --> decreased cAMP-->decreased protein kinase A=not phosphorylated)
Increased F 2,6 BP = increased PFK activity

39

Inhibition of PFK1

Fasting state (increased glucagon --> increased cAMP --> increased PKA --> increased FPBase) = gluconeogenesis

40

Arsenic poisoning

Inhibits lipoid acid
S/s vomiting, rice water stools and GARLIC BREATH

41

Pyruvate dehydrogenase complex

Links glycolysis and TCA cycle
5 cofactors: thiamine, lipoid acid, CoA (B5), FAD (B2), NAD (B3)
Same cofactors as alpha ketoglutarate dehydrogenase complex
"Tender Loving Care for Nobody"

42

Pyruvate dehydrogenase deficiency

Excess Pyruvate shunted to lactate and alanine
X linked

43

Treatment for Pyruvate dehydrogenase deficiency

Increase intake of ketogenic nutrients (high fat content or increased lysine and leucine)
LYSINE + LEUCINE (pureLy ketogenic amino acids)

44

Pyruvate metabolic pathway choices (4)

1. Alanine (alanine aminotransferase + B6)--> liver
2. Oxaloacetate (Pyruvate carboxylase + biotin) --> gluconeogenesis
3. Acetyl-CoA (Pyruvate dehydrogenase: B1, B2, B3, B5 and lipoic acid) -->TCA cycle
4. Lactate (lactic acid dehydrogenase + B3) anaerobic glycolysis

45

Kreb's Cycle produces

3 NADH, 1FADH2, 2CO2, 1GTP = 10 ATP/acetyl CoA

46

Kreb's Cycle Steps

"Cee I kan shit shit from my Oss"

Citrate, isocitrate, alpha ketoglutarate, succinylCoA, succinate, fumarate, malate, oxaloacetate

47

Electron transport chain location and flow of protons

Located in the inner mitochondrial membrane
H are pumped into the intermembrane space and flow into the mitochondrial matrix

48

Complexes that receive electrons from NADH and FADH2

Complex I: NADH
Complex II: FADH2

49

Compounds that inhibits the electron transport chain

I: rotenone, MPP , Amytal
III: antimycin
IV: cyanide, CO, N3, H2S

50

ATP synthase inhibitors:

Oligomycin

51

Uncoupling agents

Produce heat
2,4 dinitrophenol (weight loss)
Asa
Thermogenin (brown fat)

52

Gluconeogenesis irreversible enzymes

Pyruvate carboxylase
Phosphoenolpyruvate carboxykinase
Fructose 1,6 biphosphatase
Glucose 6 phosphatase

53

Pyruvate carboxylase

Mitochondria
Pyr--> oxaloacetate
Requires biotin

54

PEP carboxykinase

Oxaloacetate --> PEP
Cytosolic

55

Fructose 1,6 bisphosphate

Fructose 1,6 bisphosphate -->fructose 6 phosphate

56

Glucose 6 phosphatase

G6P-->glucose

57

Purpose and location of gluconeogenesis

Primarily in liver
Maintain euglycemia during fasting
(Enzyme deficiency - hypoglycemia)