Practicing Success

Target Exam

CUET

Subject

Biology

Chapter

Respiration in Plants

Question:

Conversion of glucose to glucose-6-phosphate, the first irreversible reaction of glycolysis, is catalyzed by which among the following enzyme ?

Options:

Enolase

Phosphofruct6kinase

Aldolase

Hexokinase

Correct Answer:

Hexokinase

Explanation:

The correct answer is Option (4)- Hexokinase

The term glycolysis has originated from the Greek words, glycos for sugar, and lysis for splitting. The scheme of glycolysis was given by Gustav Embden, Otto Meyerhof, and J. Parnas, and is often referred to as the EMP pathway. In anaerobic organisms, it is the only process in respiration.

Glycolysis occurs in the cytoplasm of the cell and is present in all living organisms. In this process, glucose undergoes partial oxidation to form two molecules of pyruvic acid. In plants, this glucose is derived from sucrose, which is the end product of photosynthesis, or from storage carbohydrates. Sucrose is converted into glucose and fructose by the enzyme, invertase, and these two monosaccharides readily enter the glycolytic pathway. Glucose and fructose are phosphorylated to give rise to glucose-6- phosphate by the activity of the enzyme hexokinase.