Chapter-10 Biomolecules — Online MCQ Test
CHEMISTRY · CLASS 12 SECOND PUC · Karnataka State Board
Practice Chapter-10 Biomolecules with a free chapter-wise online MCQ test.
This chapter covers: carbohydrates - proteins - vitamins - nucleic acids - DNA - RNA.
AI-generated questions from basic to board-exam level, with instant results and explanations.
Chapter-10 Biomolecules — Important Questions & Answers
Carbohydrates are primarily composed of which three elements?
- A. Carbon, Hydrogen, and Nitrogen
- B. Carbon, Hydrogen, and Oxygen
- C. Carbon, Oxygen, and Sulfur
- D. Hydrogen, Oxygen, and Nitrogen
Answer: B. Carbon, Hydrogen, and Oxygen
Carbohydrates follow the general formula Cn(H2O)m and contain only carbon, hydrogen, and oxygen.
Carbohydrates follow the general formula Cn(H2O)m and contain only carbon, hydrogen, and oxygen.
Which of the following is a monosaccharide?
- A. Sucrose
- B. Maltose
- C. Glucose
- D. Starch
Answer: C. Glucose
Glucose is a monosaccharide with 6 carbons (C6H12O6), while sucrose and maltose are disaccharides, and starch is a polysaccharide.
Glucose is a monosaccharide with 6 carbons (C6H12O6), while sucrose and maltose are disaccharides, and starch is a polysaccharide.
Starch and cellulose are both polysaccharides, but they differ in their:
- A. Molecular formula
- B. Monosaccharide units
- C. Glycosidic linkages and biological function
- D. Number of carbons
Answer: C. Glycosidic linkages and biological function
Both are glucose polymers, but starch has α-1,4-glycosidic bonds and is digestible, while cellulose has β-1,4-glycosidic bonds and is not digestible by humans.
Both are glucose polymers, but starch has α-1,4-glycosidic bonds and is digestible, while cellulose has β-1,4-glycosidic bonds and is not digestible by humans.
Compare starch, cellulose, and glycogen. Which statement is CORRECT?
- A. All three are glucose polymers with identical glycosidic linkages
- B. Starch and cellulose contain α-bonds; glycogen contains β-bonds
- C. Glycogen and starch are storage polysaccharides; cellulose provides structural support
- D. Cellulose is easily digested in human stomachs because it's a glucose polymer
Answer: C. Glycogen and starch are storage polysaccharides; cellulose provides structural support
Starch (in plants) and glycogen (in animals) are storage polysaccharides with α-1,4-glycosidic bonds; cellulose has β-1,4-bonds and serves a structural role.
Starch (in plants) and glycogen (in animals) are storage polysaccharides with α-1,4-glycosidic bonds; cellulose has β-1,4-bonds and serves a structural role.
A student analyzes a biomolecule and finds: (1) It contains nitrogen but no phosphorus, (2) It yields amino acids upon hydrolysis, (3) It forms a purple complex with biuret reagent. This biomolecule is definitely:
- A. A carbohydrate
- B. A nucleic acid
- C. A protein
- D. A lipid
Answer: C. A protein
Amino acids upon hydrolysis, nitrogen content, and positive biuret test (peptide bonds) are all characteristic of proteins.
Amino acids upon hydrolysis, nitrogen content, and positive biuret test (peptide bonds) are all characteristic of proteins.