Anaerobic respiration:
Anaerobic respiration is an enzyme-controlled, partial break down of organic compounds without utilising oxygen and releasing only about 7% energy of glucose. It is also called intra-molecular respiration. In this process, a net gain of 2 ATP occurs, as NAD+ is reformed to continue glycolysis. Anaerobic respiration occurs in the roots of some water-logged plants, certain parasitic worms (Ascaris and Taenia), animal muscles and some microorganisms (bacteria, moulds). In microorganisms, anaerobic respiration is often called fermentation. Kreb's cycle/TCA cycle: Discovery: This cycle has been named after Sir Hans Kreb, the German biochemist who discovered this cycle in 1937. Kreb's cycle is also known as the citric acid cycle as it is the first stable product of the cycle. This cycle takes place in the matrix of mitochondria as it has a presence of various soluble enzymes here. Like glycolysis, it also involves 10 sequential steps in which the cycle is completed. Calvin cycle: Benson and Calvin discovered the path of carbon in this process. This is known as the C3 cycle because CO2 reduction is a cyclic process and the first stable product in this cycle is a 3-C compound, i.e., 3-Phosphoglyceric acid.