Question

Incomplete oxidation of glucose into pyruvic acid with several intermediate steps is known as
A. TCA-pathway
B. Glycolysis
C. HMS-pathway
D. Krebs’ cycle

Answer 1

Hint: Respiration is the process of breaking energy rich compounds such as glucose,which produces energy in the form of ATP. ATP is the energy currency in the body of various organisms. Aerobic respiration happens when oxygen is present and anaerobic respiration occurs when there is no oxygen.
Complete step-by-step answer:
In incomplete oxidation of 6 carbon glucose molecules, 3 carbon pyruvic acid molecules are formed as an end product. This is the first step of respiration and is also known as glycolysis. ‘Glyo’ means glucose and ‘lysis’ means breaking. Glycolysis takes place in the cytoplasm of the cells and produces 2 molecules of ATP and NADH. There are various steps involved in glycolysis wherein glucose undergoes various chemical transformations. There is production and usage of ATP molecules throughout the process. Incomplete oxidation of glucose is when all hydrogen atoms of glucose are not used and hence less amount of energy is produced. Respiration takes place in mitochondria and hence, mitochondria is known as the powerhouse of the cell.
Therefore, the correct answer is option B- Glycolysis.
Note: Respiration takes in four steps-
-Glycolysis- Where glucose is broken into pyruvic acid.
-Formation of Acetyl CoA- The pyruvic acid formed above is bound Acetyl-CoA in the mitochondrial matrix.
-Krebs’ cycle- Where Acetyl- CoA forms a 4-carbon citric acid and forms FADH2 and NADH molecules which provide energy. It is also known as TCA-pathway or Citric acid cycle.
-Oxidative phosphorylation- It is a series of Redox reactions wherein FADH2 and NADH donate their electrons to oxygen atoms. ATP molecules are generated with the help of enzyme ATP synthase.