Glycolysis Flashcards
What are the 4 stages of glycolysis?
Activation (using up ATP), splitting the 6 C sugar in half, oxidation (removing 2H atoms), synthesis of ATP
What are the 3 activation steps?
Glucose is converted into glucose-6-phosphate
Then fructose-6-phosphate Then fructose 1,6 biphosphate
What is the splitting off the 6C sugar stage?
Fructose 1,6 bisphosphate is split into glyceraldehyde-3-phosphate and dihydroxyacetone phosphate
What is the oxidation stage?
Glyceraldehyde-3-phosphate is converted into 1,3-biphosphoglycerate
What are the 4 parts of the oxidation stage?
1,3-bisphosphoglycerate is converted to 3-phosphoglycerate
Then 2-phosphoglycerate
Then phosphoenolpyruvate
Then pyruvate
How much ATP is made in glycolysis?
Early stages use 2 ATP and 4 is made
Net yield - 2 ATP
How is anaerobic glycolysis different?
Pyruvate is not metabolised to CO2 instead it’s converted to lactate then converts to NADH and back to NAD+
What catalyses the reaxtion of pyruvate into L-lactate?
Lactate dehydrogenase
What can pyruvate be converted into?
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
How can hormones affect glycolysis?
Glucagon/adrenaline acn bind to cell surface receptor and activates internal signalling pathway - that activates protein kinase
Protein phosphatase is the reverse
How is the enzyme phosphofructokinase controlled?
ATP and Citrate cause negative feedback and dramatically slows down reaction rate
AMP causes positive feedback