NEET Biology: Biomolecules (proteins carbohydrates lipids nucleic acids) Practice Questions
15 free multiple-choice questions on Biomolecules (proteins carbohydrates lipids nucleic acids) (Cell Structure and Function) for NEET Biology, each with the correct answer and a step-by-step explanation. Attempt a question, then reveal the solution to check your reasoning.
Practice thousands more NEET questions in the app →Q1. In nucleic acids, the nitrogenous bases (Adenine, Guanine, Cytosine, Thymine/Uracil) are held together by which type of bond?
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Correct answer: D — Phosphodiester linkage
The nitrogenous bases are linked to each other within the nucleotide structure by phosphodiester bonds, which form the backbone of the DNA/RNA structure.
Q2. Lipids are generally characterized by which type of intermolecular forces?
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Correct answer: A — Weak Van der Waals forces
Lipids, being largely nonpolar, are held together mainly by weak Van der Waals forces, which results in relatively low melting points compared to ionic or covalent compounds.
Q3. Which type of bond is predominantly responsible for holding the fatty acid chains together in a lipid molecule?
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Correct answer: B — Ester bond
Fatty acids are linked to glycerol via ester bonds, which are characteristic linkages found in lipids.
Q4. Which type of bond is primarily responsible for holding amino acids together in a polypeptide chain?
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Correct answer: C — Peptide bond
The peptide bond is a covalent bond formed by the dehydration reaction between the carboxyl group of one amino acid and the amino group of the next amino acid, linking them together in a polypeptide chain.
Q5. Which term describes the general structural unit of a nucleic acid?
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Correct answer: C — Nucleotide
Nucleic acids (DNA and RNA) are polymers made up of repeating nucleotide units, where each nucleotide consists of a sugar, a phosphate group, and a nitrogenous base.
Q6. Which of the following functional groups is typically found in the hydroxyl (-OH) group of carbohydrates?
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Correct answer: D — Amine group
In carbohydrates (sugars), the hydroxyl group (-OH) is the key functional group, allowing for the formation of glycosidic linkages and hydrogen bonding.
Q7. The major component of the lipid molecule, which consists of a glycerol backbone and three fatty acid chains, is called:
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Correct answer: C — Triglyceride
Triglycerides (fats and oils) are formed by the ester linkage between glycerol and three fatty acids.
Q8. Amino acids are the monomer units that form proteins. What is the functional group present in every standard amino acid that dictates its basic chemical properties?
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Correct answer: A — Amino group
The amino group (-NH2) and carboxyl group (-COOH) define the structure and charge properties of amino acids, which are essential for peptide bond formation.
Q9. Which of the following is the nitrogenous base found in RNA?
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Correct answer: D — Uracil
RNA contains Uracil (U) instead of Thymine (T) in its structure, distinguishing it from DNA.
Q10. Carbohydrates are primarily characterized by the presence of which functional group in their structure?
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Correct answer: B — Hydroxyl group
Carbohydrates (sugars) are characterized by the abundance of hydroxyl (-OH) groups, making them highly polar.
Q11. Which of the following is the primary functional group found in amino acids?
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Correct answer: A — Amino group
Amino acids contain an amino group (-NH2) and a carboxyl group (-COOH), which are essential for their structure and biological roles.
Q12. Which of the following molecules acts as the monomer unit for carbohydrates?
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Correct answer: B — Monosaccharide
Carbohydrates are organic molecules that are built from smaller units called monosaccharides. Monosaccharides (like glucose and fructose) are the basic building blocks or monomers of carbohydrates.
Q13. Which of the following is the monomer unit of a carbohydrate?
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Correct answer: D — Monosaccharide
Monosaccharides (like glucose, fructose) are the basic building blocks or monomers of carbohydrates.
Q14. Which type of lipid molecule is generally characterized by a long non-polar hydrocarbon chain and a hydrophilic head group?
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Correct answer: C — Phospholipids
Phospholipids are amphipathic molecules, meaning they have both a hydrophilic (water-loving) head and hydrophobic (water-repelling) tails, making them crucial components of cell membranes.
Q15. The primary functional group present in an amino acid is:
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Correct answer: C — Amino group
Amino acids are characterized by having an amino group (-NH2) and a carboxyl group (-COOH).
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