Describe the steps of glycolysis

Step 1 (part of the investment stage req ATP)

the investment stage includes Glucose - fructose 1-6 biphosphate

phosphorylation of glucose to glucose 6 phosphate (the enzyme that cleaves the ATP is hexokinase an ATPase enzyme)

Step 2 - conversion of glucose-6-phosphate to fructose 6 phosphate

(the enzyme involved is phosphoglucose isomerase) does not require ATP

Step 3 - fructose - 6 - phosphate conversion to fructose 1,6 bi-phosphate

Requires ATP (part of the investment stage)

this is PFK (phosphofructokinase) key regulatory point

step 4 - Aldolase cleaves the Fructose 1,6 biphosphate into glyceraldehyde-3-phosphate (GAP) and Dihydroxyacetone

step4 is the end of the investment stage

(step 5 is a reversible reaction between glyceraldehyde-3-phosphate and dihydroxyacetone)

step 6 - oxidation & phosphorylation of Glyceraldehyde-3-phosphate (GAP) by NAD and Pi

the enzyme used - glyceraldehyde 3-phosphate dehydrogenase

the use of NAD and Pi acts as an energy source for the GAP- 13-bisphosphoglycerate to be made this is a

and 1,3-Bisphosphoglycerate x2

in aerobic conditions means that the 2NADH + 2H created by the energy releasing reaction of NAD + Pi will continue onto the citric acid cycle

step 7 - first formation of ATP

1,3-Bisphosphoglycerate is cleaved of a phosphate group by phosphoglycerate kinase to create 2 ATP and 3-phosphoglycerate (3PG)

step 8 - 3PG converted to 2PG 2-phosphoglycerate. (pi group moved to carbon 2)