Cell Metabolism 1 - Overview

Question 1

Glycolysis

Answer 1

Anaerobic process in cytoplasm of cells

Question 2

Two main concepts of glycolysis pathway

Answer 2

• formation of high energy compound (uses ATP)

-splitting of high energy compound (releases ATP)

Question 3

Overall, what happens in glycolysis?

Answer 3

Glucose converted into x2 pyruvate

Question 4

Step 1: what happens?

Answer 4

Glucose —> glucose-6-phosphate

Glucose is phosphorylated
Enzyme: hexokinase

ATP —>ADP

Question 5

Step 1: what type of reaction is it?

Answer 5

Group transfer

Irreversible - commits cell to subsequent reactions

Question 6

Step 2: what happens?

Answer 6

Converted into fructose-6-phosphate - can be split evenly

Enzyme: phosphoglucose isomerase

Question 7

Step 2: what type of reaction is it?

Answer 7

Isomerisation

Question 8

Step 3: what happens?

Answer 8

Fructose-6-phosphate phosphorylated (C1) to make fructose-1,6-phosphate

Enzyme: phosphofructokinase —> regulation is key control step for entry of sugars into glycolysis pathway

ATP —> ADP

Question 9

Step 3: what type of reaction is it?

Answer 9

Group transfer

Irreversible

Rate limiting step

Question 10

Step 4: what happens?

Answer 10

Two high energy (due to phosphate group) compounds generated (cleaved):
- dihydroxyacetone phosphate
- glyceraldehyde-3-phosphate (can pass through glycolysis)

Enzyme: aldolase

Question 11

Step 4: what type of reaction is it?

Answer 11

Hydrolytic

Question 12

Step 5: what happens?

Answer 12

Dihydroxyacetone phosphate converted to glyceraldehyde-3-phosphate

Enzyme: triode phosphate isomerase —> deficiency is fatal

Question 13

Step 5: what type of reaction is it?

Answer 13

Isomerisation

Question 14

Step 6: what happens?

Answer 14

Glyceraldehyde 3-phosphate converted to 1,3-bisphosphateglycerate

Enzyme: glyceraldehyde 3-phosphate dehydrogenase

NAD+ + Pi —> NADH

Question 15

Step 6: what type of reaction is it?

Answer 15

Redox —> H removed from G3P and added onto NADH+

Group transfer —> phosphate added

Question 16

Step 7: what happens?

Answer 16

1,3-bisphosphoglycerate converted into 3-phosphoglycerate

ATP formed

Enzyme:phosphoglycerate kinase

Question 17

Step 7: what type of reaction is it?

Answer 17

Phosphorylation

Group transfer

Question 18

Step 8: what happens?

Answer 18

3-phosphoglycerate converted to 2-phosphoglycerate

Enzyme: phosphoglycerate mutase

Question 19

Step 8: what type of reaction is it?

Answer 19

Isomerisation —> phosphate group goes from 3C to 2C

Question 20

Step 9: what happens?

Answer 20

2-phosphoglycerate converted to phosphoenolpyruvate

Enzyme: enolase

Question 21

Step 9: what type of reaction is it?

Answer 21

Dehydration react

Group remova

Question 22

Step 10: what happens?

Answer 22

Phosphoenolpyruvate converted into pyruvate

ATP formed

Enzyme: pyruvate kinase

Question 23

Step 10: what type of reaction is it?

Answer 23

Irreversible

Group transfer

Question 24

Net result of glycolysis

Answer 24

2 ATP

2NADH