The term cellular respiration is an oxidation-reduction process in which organic food is broken-down inside the cell and energy is released, Hence it is the form of catabolic process.
Cellular respiration includes both aerobic and anaerobic processes.
The harvesting of energy from glucose by cellular respiration is
a cumulative function of three metabolic stages.
Glycolysis, PYRUVATE OXIDATION and the CITRIC ACID CYCLE or Kreb's Cycle, and Electron Transport Chain ( ETC).
Glycolysis, which occurs in the cytosol, begins the degradation process by breaking glucose into two molecules of a compound called
pyruvate.
The word glycolysis means “sugar splitting,” and that is exactly what happens during this pathway. Glucose, a sixcarbon sugar, is split into two three-carbon sugars. These smaller sugars are then oxidized and their remaining atoms rearranged to form two molecules of pyruvate. (Pyruvate is
the ionized form of pyruvic acid.)
glycolysis can be divided into two phases: the energy investment phase or preparatory phase and the energy payoff phase or Oxidative phase. During the energy investment phase, the cell actually spends ATP. This investment is repaid with interest during the energy payoff phase, when ATP is produced
by substrate-level phosphorylation and NAD+ is reduced to NADH by electrons released from the oxidation of glucose.
The net energy yield from glycolysis, per glucose molecule,
is 2 ATP plus 2 NADH.
#IntracellularRespiration