Question

Explain these terms in 3-4 lines :
(a) Anearobic respiration
(b) Glycolysis
(c) Cristae
(d) Oxidative phosphorylation
(e) Elementary particles
(f) Co-enzymes
(g) Energy currency of cells.

Answer 1

(a) Anaerobic respiration: It is a type of respiration which takes place in the absence of oxygen. The end product of this reaction is lactic acid or alcohol and carbon dioxide instead of water and carbon dioxide. It produces very less energy as compared to aerobic respiration. It results in the incomplete break down of glucose.

(b) Glycolysis: It is a process in which glucose is broken down into pyruvic acid. It releases energy in the form of ATP molecules. It takes place in the cytoplasm. It occurs in the absence of oxygen.

(c) Cristae: These are folds found on the inner membrane of the mitochondria. It provides a large surface area for various reactions to occur. Electron transport chain of cellular respiration takes place in cristae.

(d) Oxidative phosphorylation: It is a process of synthesizing energy-rich ATP molecules with the help of energy liberated during oxidation of reduced co-enzymes (NADH, FADH${}_2$) that are produced during respiration.

(e) Elementary particles: The inner membrane of mitochondria and cristae possess numerous tennis racket-like particles called as oxysomes. They are also called as elementary particles or Parson's particles. Each mitochondria contains about 104 -105 elementary particles.

(f) Co-enzymes: Coenzymes are helper molecules that bind to the enzyme and activates the enzyme. Coenzymes along with apoenzymes make active holoenzyme. An example includes Thiamine pyrophosphate (TPP).

(g) Energy currency of cells: ATP is called as the energy currency of cells. These are energy-rich molecules. It is made up of adenosine and three phosphate groups. It stores and transfers energy in the cell whenever required. The removal of the terminal phosphate group from ATP releases energy and ADP is formed.