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Flashcards in Glycolysis Deck (24)
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1

Purpose of glycolysis

Universal pathway in cytoplasm of All cells to produce ATP and 3/6C intermediates

- can be aerobic or anaerobic

2

Anaerobic glycolysis

Pyruvate is reduced to lactate via oxidation of NADH

(Converts glucose to 2 lactate)

Very minimal ATP production (2)

ONLY pathway of ATP production in the absence of O2

3

Priming stage of glucolysis

Glucose -> fructose 1,6 biphosphate

Enzyme hexokinase phosphorylate glucose -> G6P

Enzyme phosphohexonse isomerase changes G6P - > F6P

Enzyme phosphofructo Kinase 1 phosphorylate F6P -> F 1,6BP


4

Enzymes involved in irreversible steps of glycolysis

Hexokinase

Phosphofructo kinase 1

Pyruvate kinase

- if any of these enzymes are deactivated in anyway, glycolysis DOES NOT occur

5

Cleavage stage of glycolysis

Enzyme aldolase cleaves F 1,6BP -> GA3P and DHAP

- triode phosphate isomerase transforms DHAP into GA3P forming 2 G3P molecules
( done because only GA3P can be used in the oxidative stage)

6

Aerobic glycolysis

Converts pyruvate to acetyl CoA

Large-scale ATP via oxidative phosphorylation

7

Molecules that can be catabolized by glycolysis pathway

Glucose, fructose, galactose and ribose

8

Priming intermediates

Glucose ->

G6-P ->

F6-P ->

F1,6-BP

9

Hexokinase or Glucokinase
(HK/GK)

Uses ATP to phosphorylate Glucose -> G6-P

-Irreversible reaction

10

Phosphofructo kinase 1 (PFK1)

Uses ATP to phosphorylate F6-P
-> F1,6-BP

- irreversible reaction

11

Cleavage intermediates

F1,6-BP

GA3-P

DHAP

12

Aldolase

Cleaves F1,6-BP into GA 3-P & DHAP

13

Triose phosphate isomerase

Converts DHAP into GA 3-P

- does this because DHAP is not able to be oxidized in step 3

14

Oxidation and ATP production intermediates

GA-3P

PEP

Pyruvate

15

Pyruvate Kinase

Converts PEP into pyruvate

-irreversible reaction

16

GA-3P produces what in glycolysis?

2 NADH

2 ATP

17

PEP produces what in oxidation when converted to pyruvate?

2 ATP

18

Net products for glycolysis

2 pyruvate

2 NADH

2 ATP
4 (produced in step 3) - 2 (consumed in step 1)

19

Anaerobic glycolysis net products

2 ATP

2 NAD+ (used in future glycolysis reactions)

20

Enzyme used in anaerobic glycolysis that reduces pyruvate to lactate

Lactate dehydrogenase

- oxidizes NADH to NAD+

21

Total ATP produced in aerobic glycolysis

30-32

22

What cells undergo anaerobic glycolysis

Cells without mitochondria

Cells experiencing hypoxia

23

Why cant aerobic glycolysis occur in the cytoplasm only?

NADH and NAD+ are impermeable to the inner membrane of mitochondria.

- in order to regenerate NADH molecules, two shuttle systems are used to move electrons into the mitochondrial matrix

24

Two different electron shuttle systems used in aerobic glycolysis

1) electrons use FADH2 as an electron carrier

2) electrons use already produced NADH as electron carriers (3-5 ATP producers)