2017 Biochemistry - Glycolysis Flashcards Preview

2017 Semester 1 > 2017 Biochemistry - Glycolysis > Flashcards

Flashcards in 2017 Biochemistry - Glycolysis Deck (20):
1

Reactants and Products of Hexokinase/Glucokinase - Step 1?

Glucose + ATP -> G6P

2

Reactants and Products of Phosphofructokinase - Step 3?

Fructose-6-P + ATP -> Fructose-1,6-bisphosphate

3

Reactants and Products of Pyruvate Kinase - Step 9?

Phosphoenolpyruvate + ADP -> Pyruvate + ATP

4

Which steps of Glycolysis produce ATP?

Step 6 & 9
Phosphoglycerate kinase and Pyruvate Kinase

5

Which steps of Glycolysis use ATP?

Step 1 & 3
Hexokinase/Glucokinase and Phosphofructokinase

6

What are the 3 enzymes responsible for the irreversible steps of Glycolysis?

Hexokinase/Glucokinase - step 1
Phosphofructokinase - step 3
Pyruvate kinase - step 9 & final step

7

Differences/Similarities between Hexokinase and Glucokinase?

Glucokinase - present only in liver, kidney and B cells, low affinity = function is to remove glucose from blood following a meal, not inhibited by G6P.

Hexokinase - present in all tissues, very high affinity = saturated under normal condition and acts as a constant rate, Inhibited by G6P

8

Aerobic Glycolysis; products, ATP produced, shuttle system

-Pyruvate is converted to acetyl-CoA in mitocondria for TCA cycle
-Oxidation of ACoA will lead to 36 ATP produced
-Under aerobic conditions NADH which is produced may be re-oxidized by mitochondria through a shuttle system.

9

Primary purpose of Anaerobic Glycolysis?

To regenerate NAD+ using the G3P shuttle.
This allows NADH equivalents to get out of the mitochondria.
Pyruvate is reduced to Lactate

10

What are the inhibitors of Hexokinase?

Glu-6-P, ATP

11

What are the Activators/Inhibitors of PFK-1?

Activators: F-2,6-bP, AMP
Inhibitors: Citrate, ATP

12

What are the Activators/Inhibitors of Pyruvate Kinase?

Activators: F-2,6-bP, AMP
Inhibitors: Acetyl-CoA, ATP

13

What enzyme is used in Erythrocytes to bypass the "normal" route from Glyceraldehyde-3-p --> 3-Phosphoglycerate, which product is made in place of 1,3-bPG and what is it's importance?

Biophosphglycerate mutase
2,3-bPG is made in RBCs which binds to Hb and decreases it's affinity for O2, thus freeing O2 for use in tissue.

14

What are the 3 enzymes important to fructose metabolism?

Fructokinase: Fructose + ATP -> Fructose-1-p
Adolase B: Fructose-1-p Glyceraldehyde + Dihydroxyacetone phosphate
Triose Kinase: Glyceraldehyde + ATP -> Glyceraldehyde-3-phos.

15

Which enzyme of fructose metabolism is blocked in Essential Fructosuria?

Fructokinase

16

Which enzyme of fructose metabolism is blocked in Hereditary Fructose Intolerance?

Aldolase B

17

Galactose metabolism: important enzymes and resultant product

1. Galactokinase
2. UPD-Glc:Gal-1-P uridylyltransferase
3. Phosphoglucomutase

Results in Glucose-6-P production

18

Which enzyme is lacking/faulty in Galactosemia?

Galactose-1-phosphate uridyltransferase

19

Mannose metabolism: important enzymes and resultant products

Mannose Kinase (liver) converts mannose to Mannose-6-P
Phosphomannose isomerase catalyzes Mannose-6-P to F-6-P

20

One molecule of glucose converts to how many molecules of pyruvate through Glycolysis?

1 molecule glucose = 2 molecules of pyruvate