Name: Components of Electron Transport System
Uploaded: 2019-07-19
Duration: 6 min 2 s
Description: Light energy from the sun is trapped and relayed between a series of photosystems and electron carriers to produce energy and oxygen. Learn about the parts o...

Question

Give an account of glycolysis. Where does it occur? What are the end products? Trace the fate of these products in both aerobic and anaerobic respiration.

Accepted Answer

Glycolysis is the process in which one glucose molecule is broken down to form two molecules of pyruvic acid or pyruvate. The process of glycolysis takes place in the cytosol of a cell and marks the beginning of cellular respiration. It is enzyme mediated process which is completed in several steps. It is also known as EMP pathway on the name of its discoverers Embden, Meyerhof, and Parnas.

Following are the important steps of glycolysis.

Glucose undergoes phosphorylation to produce glucose-6 -phosphate.

Fructose-6-phosphate is then converted into PGAL (Phosphoglyceraldehyde).

Each molecule of PGAL then undergoes several steps to produce Pyruvic Acid, which is the end product of glycolysis.

Glycolysis occurs in the cytoplasm of the cell. The end products of glycolysis are two molecules of pyruvic acid, two ATP and two NADH₂ molecules.

The fate of pyruvate: There are two fates of the pyruvic acid.

Aerobic Respiration: Pyruvic acid is completely oxidized to produce carbon dioxide and energy. At first, pyruvic acid is changed to acetyl coenzyme A which is starting point of Kreb's cycle. NADH₂ molecules are transported to mitochondria through shuttle mechanism where they produce ATP. Acetyl coenzyme A enters into Kreb's cycle. There are 38 ATP molecules formed from the aerobic respiration.

Anaerobic Respiration: Depending upon the availability of oxygen in some organisms, pyruvic acid is converted into ethanol and carbon dioxide when there is a complete absence of oxygen. In some other cases, pyruvic acid is converted into lactic acid when there is incomplete oxygen supply. There are 2 ATP molecules produced in this process.

Give an account of glycolysis. Where does it occur? What are the end products? Trace the fate of these products in both aerobic and anaerobic respiration.

Important Questions on Respiration in Plants

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