Free Biological Molecules MCQs with Answers

• A. More sweet
• B. Release more energy at the time of oxidation
• C. More stable for oxidation
• D. Occupy less space

Explanation: Fructose is indeed sweeter than glucose, so storing it in ripening fruits enhances their sweetness, making them more attractive to animals…

• A. Similar triplet code for amino acids
• B. Energy is stored by high phosphate bonds
• C. Type of protein present in the body
• D. Ribosomes are the sites of protein synthesis

Explanation: This is the correct answer. The type of proteins present in the body can vary among different organisms.

• A. Sucrose is a disaccharide
• B. Uracil is a pyrimidine
• C. Glycine is a sulphur-containing amino acid
• D. Cellulose is a polysaccharide

Explanation: This statement is incorrect. Glycine is the simplest amino acid and does not contain sulphur in its structure.So, the incorrect statement…

• A. 1
• B. 2
• C. 3
• D. 4

Explanation: The correct answer is 3. A typical fat or oil molecule is known as a triglyceride, which is composed of a glycerol backbone attached to…

• A. An aldehyde group and an amino group
• B. An aldehyde group and a carboxyl group
• C. An aldehyde group and an ester group
• D. A carboxyl group and an amino group

Explanation: A peptide bond is a covalent bond that forms between the carboxyl group of one amino acid and the amino group of another amino acid.

• A. Assertion and reason both are correct statements and reason explains the assertion
• B. Assertion and reason both are correct statements but reason does not explain assertion
• C. Assertion is a correct statement and reason is a wrong statement
• D. Assertion is the wrong statement and the reason is the correct statement

Explanation: Assertion and reason both are correct statements, and reason explains the assertion.

• A. Van der Waals forces
• B. Electrostatic forces of attraction
• C. Hydrogen bonds
• D. Covalent bonds

Explanation: This is the correct answer. Fibrous proteins often have secondary structures stabilised by hydrogen bonds.

• A. TCCGAACT
• B. TACGTAGT
• C. TACGAATC
• D. TACGAACT

Explanation: To determine the complementary strand of DNA, you need to use the base-pairing rules:- Adenine (A) pairs with Thymine (T),- Thymine (T)…

• A. Peptide bonds between -NH2 and CO groups of adjacent carbon chains
• B. Hydrogen bonds between NH of amino acid in one turn with CO of amino acid in adjacent turns
• C. OH group of one amino acid with CO group of other amino acids on the turn
• D. Hydrogen bonds between adjacent amino acids

Explanation: In an alpha-helix, hydrogen bonds form between the carbonyl oxygen (CO) of one amino acid and the amide hydrogen (NH) of an amino acid…

• A. The sequence of amino acids in the polypeptide chain
• B. The formation of hydrogen bonds leading to alpha-helices and beta-pleated sheets
• C. The formation of peptide bonds between amino acids
• D. The folding of the coiled polypeptide chain into a three-dimensional shape

Explanation: The secondary structure of a protein refers to the regular local structures that form within a polypeptide due to hydrogen bonding.

• A. Condensation
• B. Glycolysis
• C. Hydrolysis
• D. Oxidation

Explanation: Polysaccharides in plants are synthesized through condensation reactions.

• A. Condensation
• B. Deamination
• C. Hydrolysis
• D. Phosphorylation

Explanation: The correct answer is condensation. This reaction involves the joining of amino acids through the formation of peptide bonds, releasing a…

• A. Cellulose
• B. Cholesterol
• C. Glycerol
• D. Insulin

Explanation: Glycerol has three OH groups as it forms bonds with three fatty acid molecules.

• A. Option A
• B. Option B
• C. Option C
• D. Option D

Explanation: Basic amino acids have an additional amino group without forming amides thus they are diamino monocarboxylic acids e.g., arginine, lysine…

• A. Option A
• B. Option B
• C. Option C
• D. Option D

Explanation: The correct answer is Option A. Glucose is soluble in water because it contains many polar hydroxyl (-OH) groups that can form hydrogen…

• A. β-glucose molecules
• B. Fibrillar structure
• C. 1-6 glycosidic bonds
• D. Hydrogen bonds

Explanation: The correct answer is Option C: 1-6 glycosidic bonds. Cellulose is composed of β-glucose molecules linked by 1-4 glycosidic bonds, forming…

• A. Less regular in structure
• B. Less stable chemically
• C. More readily soluble
• D. More resistant to high temperatures

Explanation: Fibrous proteins, such as collagen and keratin, have highly ordered structures and are known for their mechanical strength and resistance…

• A. It contains both α-1, 4 and α-1, 6 links between glucose units
• B. It has OH groups that form hydrogen bonds with adjacent cellulose molecules
• C. It is a fibrous molecule that is insoluble in water
• D. It is made up of long, branched and coiled chains of β-glucose units with 1, 4 links

Explanation: Cellulose is a polysaccharide consisting of β-glucose units linked by β-1, 4 glycosidic bonds.

• A. CH3CHO
• B. C2H5OH
• C. C3H6O3
• D. C15H31COOH

Explanation: Carbohydrates generally follow the formula Cn(H2O)m. Option C, C3H6O3, follows this formula (where n = 3 and m = 3), making it a…

• A. Primary and Secondary
• B. Secondary and Tertiary
• C. Primary and Quaternary
• D. Secondary and Quaternary

Explanation: The correct answer is D) Secondary and Quaternary. The statements describe features of both the secondary and quaternary structures of…