Krebs cycle is a series of reaction that takes place in living cells. This cycle was discovered by Hans Krebs. For this discovery he shared Nobel price for 1953.
During the Krebs Cycle acetyl coenzyme A to carbon dioxide and water. The Krebs cycle consists of the following steps
- Acetyl coenzyme combines with oxaloacetic acid forming citric acid.
- Rearrangement of the citric acid molecules produce isocitric acid.
- Isocitric acid passes through a series of stages of forming by turn following six acids: a-ketoglutaric, succinic, succinyl-coenxyme A, Fumaric, malic and oxaloacetic acids.
The oxaloacetic acid is then recycled to to step i of the Kreb cycle. Each step of the Krebs cycle provides energy to the cell.
Malic Acid, Alpha-ketoglutaric Acid, Succinic Acid, Fumaric Acid, Citric Acid, Pyruvic
Acid, Pantothenic Acid are the intermediate compounds formed during the Krebs cycle
and are much significant in producing the energy required for cellular activities.
Malic acid serves as a catalyst in the Krebs cycle in order to increase energy production
from the pyruvic acid. Malic acid neutralizes the increase of lactic acid in the muscles
during heavy exercises and also helps in exercise recovery.
Alpha-ketoglutaric Acid (AKG)
Alpha-ketoglutaric acid is the precursor of the amino acid, glutamic acid and is a key
factor in the Krebs cycle production of energy.
Succinic acid is similar to the other Krebs cycle intermediates. It acts as an access for
other metabolites to participate into the cycle.
Fumaric acid is the trans-isomer of malic acid which comes into the citric acid cycle.
Citric acid is a natural organic acid which is present in most of the citrus fruits like
oranges, grapes etc.
Pyruvic acid also possesses the tendency to increase the amount of glucose that enters
muscle cells from the circulating blood.
Pantothenic Acid is also called as Vitamin B5 which is water soluble, found in almost
every food, with high amounts in legumes, meat and egg and essential for the body
Significance of TCA cycle:
When these essential Krebs cycle acids are administered along with the nutrient
cofactors, even a partially completed Krebs cycle can be made complete. This feature
makes them gain much importance.