Glycolysis

Question 1

What are the 4 stages of glycolysis?

Answer 1

Activation (using up ATP), splitting the 6 C sugar in half, oxidation (removing 2H atoms), synthesis of ATP

Question 2

What are the 3 activation steps?

Answer 2

Glucose is converted into glucose-6-phosphate

Then fructose-6-phosphate Then fructose 1,6 biphosphate

Question 3

What is the splitting off the 6C sugar stage?

Answer 3

Fructose 1,6 bisphosphate is split into glyceraldehyde-3-phosphate and dihydroxyacetone phosphate

Question 4

What is the oxidation stage?

Answer 4

Glyceraldehyde-3-phosphate is converted into 1,3-biphosphoglycerate

Question 5

What are the 4 parts of the oxidation stage?

Answer 5

1,3-bisphosphoglycerate is converted to 3-phosphoglycerate
Then 2-phosphoglycerate
Then phosphoenolpyruvate
Then pyruvate

Question 6

How much ATP is made in glycolysis?

Answer 6

Early stages use 2 ATP and 4 is made

Net yield - 2 ATP

Question 7

How is anaerobic glycolysis different?

Answer 7

Pyruvate is not metabolised to CO2 instead it’s converted to lactate then converts to NADH and back to NAD+

Question 8

What catalyses the reaxtion of pyruvate into L-lactate?

Answer 8

Lactate dehydrogenase

Question 9

What can pyruvate be converted into?

Answer 9

Anaerobically - lactate
By micro-organisms - ethanol
Aerobically - acetyl CoA this goes into the citric acid cycle and ends as CO2 or becomes fatty acids if excess calories present

Question 10

How can hormones affect glycolysis?

Answer 10

Glucagon/adrenaline acn bind to cell surface receptor and activates internal signalling pathway - that activates protein kinase
Protein phosphatase is the reverse

Question 11

How is the enzyme phosphofructokinase controlled?

Answer 11

ATP and Citrate cause negative feedback and dramatically slows down reaction rate
AMP causes positive feedback