GlycolysisRahman R Hillol

KGHS,Dhaka.

What is Glycolysis

Glycolysis (from the Greek glykos, meaning sweet, andlysis, meaning splitting) involves the breakdown ofglucose, a simple sugar. This process can occur in thepresence or absence of oxygen, that is, under aerobicor anaerobic conditions.

History of Glycolysis

During the 1930s, the efforts of several Germanbiochemists, including Gustav Embden, Otto Meyerhof,and Jacob Parnas, determined that glycolysis involves10 steps, each one catalyzed by a different enzyme.

Concept of Glycolysis

Glycolysis

Step 1

ATP ADP

Glucose

Glucose is phosphorylated by ATP. Glucose-6-phosphate is more easily trapped in the cell compared to glucose.

Glucose-6-Phosphate

Hexokinase

Step 2

The structure of glucose-6-phosphate is rearranged to fructose-6-phosphate.

Glucose-6-Phosphate

Phosphoglucoisomerase

Fructose-6-phosphate

Step 3

ATP ADP

Fructose-6-phosphate is phosphorylated to make fructose-1,6-bisphosphate.

Phosphofructokinase

Fructose-6-phosphateFructose-1,6-bisphosphate

Fructose-1,6-bisphosphate

Dihydroxyacetonephosphate

Glyceraldehyde-3-phosphate (x2)

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

4.

Aldolase

4.Di-hydroxyl-acetone phosphate is somerized to glyceraldehyde-3-phosphate.5.

Isomerase5.

Glyceraldehyde-3-phosphate (x2)

1,3-bisphosphoglycerate (x2)

Unstable PhosphateBond

2 NAD+

Glyceraldehyde-3-phosphate

dehydrogenase

2NADH

+2H+

Glyceraldehyde-3-phosphate is oxidized to 1,3-bisphosphoglycerate. NADH is produced. In 1,3-bis-phospho-glycerate,the phosphate group in the upper left is destabilized, meaning that the bond will break in a highly exergonic reaction.

6.

1,3-bisphosphoglycerate (x2)

Unstable PhosphateBond

2ATP 2ADP

Phosphoglycero–kinase

A phosphate is removed from 1,3-bis-phospho-glycerate to form 3-phosphor-glycerate. The removed phosphate is transferred to ADP to make ATP via substrate-level phosphorylation.

7.

3-phosphoglycerate(x2)

3-phosphoglycerate(x2) 2-phosphoglycerate(x2)

Phosphoglycero–mutase

The phosphate group in 3 phosphoglycerateis moved to a new location, creating 2-phosphoglycerate

8.

2-phosphoglycerate(x2)

Unstable phosphatebond

Phosphoenolpyruvate(x2)

A water molecule is removed from 2-phosphor-glycerate to form phosphor-enol-pyruvate. In phosphor-enol-pyruvate, the phosphate group is destabilized, meaning that the bond will break in a highly exergonic reaction.

9.

Enolase

Unstable phosphatebond

Phosphoenolpyruvate(x2) pyruvate(x2)

Pyruvate Kinase

2ADP 2ATP

A phosphate is removed from phosphor-enol-pyruvate to form pyruvate. The removed phosphate is transferred to ADP to make ATP via substrate-level phosphorylation.

10.

Thanks God! It’s over at last!!

:p