Metabolism of Microorganisms

Metabolism of Microorganisms:- Dr. Lamees A.Razzak
Metabolism:-
Refers to the sum of the biochemical reactions required for energy generation and the use of energy to synthesize cell material from small molecules in the environment. Metabolism consists of catabolism and anabolism reactions:-
1-Anabolism reactions:-
Are energy-requiring subset of metabolic reactions, which synthesize large molecules from smaller ones.
1- Catabolism reactions:-
Are the energy–releasing subset of metabolic reactions, which degrade or breakdown large molecules into smaller ones.
*ATP (adenosine triphosphate):-
During catabolism, useful energy is temporarily conserved in the "high energy bond" of ATP. When energy is required during anabolism, it may be spent as the high energy bond of ATP which has a value of about 8 kcal per mole. Hence, the conversion of ADP to ATP requires 8 kcal of energy, and the hydrolysis of ATP to ADP releases 8 kcal.
*NAD (Nicotinamide Adenine Dinucleotide):-
Another coenzyme commonly involved in energy-producing metabolism, derived from the vitamin niacin, is the pyridine nucleotide, NAD. The basis for chemical transformations of energy usually involves oxidation/reduction reactions. For a biochemical to become oxidized, electrons must be removed by an oxidizing agent. The oxidizing agent is an electron acceptor that becomes reduced in the reaction. During the reaction, the oxidizing agent is converted to a reducing agent that can add its electrons to another chemical, thereby reducing it, and oxidizing itself. The molecule that usually functions as the electron carrier in these types of coupled oxidation-reduction reactions in biological systems is NAD and its phosphorylated derivative, NADP. NAD or NADP can become alternately oxidized or reduced by the loss or gain of two electrons. The oxidized form of NAD is symbolized NAD; the reduced form is symbolized as
NADH, NADH2 or NADH + H+.