Question

16. Which carbohydrate cannot be hydrolyzed (broken down into smaller units a. Glucose b. Sucrose Lactose d. starch e. Glycogen

Answer 1

Correct Option

a. Glucose - Glucose is the simplest form of carbohydrate which is used in cellular respiration for energy production. Glucose undergoes glycolysis and produce various molecules needed for energy production in cell. For example, glycolysis generates pyruvate which is required for TCA cycle. In TCA cycle, NADH and FADH2 are generated which participates in oxidative phosphorylation and electron transfer for ATP synthesis in mitochondria.

Incorrect Options (with reasons)

b. Sucrose is a disaccharide. Break down of sucrose converts into monosaccharides glucose and fructose. In human body sucrase enzyme catalyse this reaction.

c. Like sucrose, lactose is also broken down into monosaccharides glucose and galactose. Enzyme lactose catalyse this reaction in human body.

d. Starch is a polymeric carbohydrate. It can be broken down into smaller sugar molecules and monomeric glucose by various enzymes. In human body, starch break down or digestion begins in mouth due to action of salivary amylase. Starch is broken down into Maltose (a 2 Glucose sugar).

e. Glycogen is a stored carbohydrate in liver and muscles. It is broken down into glucose in a process called glycogenlysis. Glucose is then used in cellular respiration for energy production.

Find it helpful? Please click on thumbs up! :)