GLYCOLYSIS PATHWAY.

Glycolysis is the metabolic pathway that breaks down glucose to produce energy. 

PLACE-

It occurs in the cytoplasm of cells and can function both aerobically and anaerobically.

 Here’s a simplified overview of the glycolysis pathway, which consists of ten enzyme-catalyzed reactions:

Overview of Glycolysis:

1.Glucose → Glucose-6-Phosphate

*Enzyme:Hexokinase.

*ATP used: 1

2.Glucose-6-Phosphate → Fructose-6-Phosphate

*Enzyme: Phosphoglucose isomerase.

3.Fructose-6-Phosphate → Fructose-1,6-Bisphosphate

*Enzyme: Phosphofructokinase-1 (PFK-1)

*ATP used: 1 (Key regulatory step).

4.Fructose-1,6-Bisphosphate → Glyceraldehyde-3-Phosphate + Dihydroxyacetone Phosphate

*Enzyme: Aldolase.

5.Dihydroxyacetone Phosphate → Glyceraldehyde-3-Phosphate

*Enzyme: Triose phosphate isomerase.

6.Glyceraldehyde-3-Phosphate → 1,3-Bisphosphoglycerate.

*Enzyme: Glyceraldehyde-3-phosphate dehydrogenase

*NAD+ reduced to NADH

7. 1,3-Bisphosphoglycerate → 3-Phosphoglycerate

*Enzyme: Phosphoglycerate kinase

*ATP produced: 1 (substrate-level phosphorylation)

8. 3-Phosphoglycerate → 2-Phosphoglycerate

Enzyme: Phosphoglycerate mutase.

9. 2-Phosphoglycerate → Phosphoenolpyruvate

Enzyme: Enolase.

10. Phosphoenolpyruvate → Pyruvate

Enzyme: Pyruvate kinase

ATP produced: 1 (substrate-level phosphorylation).

Key Outputs of Glycolysis:

*Net ATP: 2 ATP (4 produced, 2 used)

*NADH: 2 NADH

*Pyruvate: 2 molecules of pyruvate

Importance of Glycolysis:

Energy Production: Provides ATP for cellular processes.

*Precursor for Other Metabolic Pathways: Pyruvate can enter the Krebs cycle (aerobic) or be converted to lactate (anaerobic).

*Regulation: Key enzymes (like PFK-1) are tightly regulated, responding to cellular energy levels.

*Glycolysis is a important step in cellular respiration, providing both energy and intermediates for various biosynthetic pathways.