Glycolysis

Question 1

What is glycolysis?

Answer 1

This is a metabolic pathway which converts glucose into pyruvate - generating ATP.
Reduces NAD+ to NADH = storing energy as reducing power.

Question 2

Where does glycolysis take place?

Answer 2

Takes place in cytoplasm.

Question 3

What is the net production of glucose per glucose molecule?

Answer 3

Overall net gain is 2 molecules of glucose.

Question 4

What does glucose do?

Answer 4

Glucose lowers the blood sugar levels via the process of signal transduction.

Question 5

What are two main stages of glycolysis?

Answer 5

The two main stages of glycolysis are:

• Energy investment phase.
• Energy payoff phase.

Question 6

Explain what happens in the ‘energy investment phase’.

Answer 6

Steps 1 - 5 occur in the energy investment phase.
Glucose is converted to 2 ‘glyceraldehyde 3-phosphate’ molecules.
And at this point: 2 ATPS are invested.

Question 7

Explain what happens in the ‘energy payoff phase’.

Answer 7

Steps 6 - 10 occur in the energy payoff phase.
The 2 ‘glyceraldehyde 3-phosphate’ molecules are converted to pyruvate and 4 ATP molecules.
And at this point: 2 ATP molecules overall plus 2 NADH molecules is the net overall change.

Question 8

Why is glycolysis controlled?

Answer 8

The glycolytic pathway is carefully controlled according to the energy needs of cell.

Question 9

How is glycolysis controlled in muscle cells?

Answer 9

In muscle cells, the level of ATP and AMP is used as a signal for energy availability.

Question 10

What happens to glycolysis when there are high (ATP) signals?

Answer 10

This indicates the cell has enough energy and therefore, glycolysis is inhibited.

Question 11

What happens to glycolysis when there are low (ATP) signals?

Answer 11

This indicates the cell does not have enough energy and therefore, glycolysis is activated.