Free Biological Molecules MCQs with Answers
1,790 Biological Molecules MCQs from Biology, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
The chapter covers water's polarity and biological roles, carbohydrates, lipids, proteins and nucleic acids, including their monomers, bonds, structures and functions. It also distinguishes RNA from DNA and explains conjugated molecules such as glycoproteins, glycolipids and nucleoproteins, which combine organic molecules with a non-protein component.
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1,790 questions · page 48 of 90
- A. Glycine
- B. Acetone
- C. Glucose
- D. Ethanol
Explanation: The correct answer is Glycine, as it is a basic amino acid with both an amino group (-NH2) and a carboxyl group (-COOH) attached to the…
Correct answer: Glycine- A. CONH2
- B. -COONH2
- C. -CONH
- D. -CH-NH
Explanation: The peptide bond is a covalent linkage formed between the carboxyl group of one amino acid and the amino group of another amino acid.
Correct answer: -CONH- A. Maltose
- B. Glycine
- C. Cellulose
- D. Cellobiose
Explanation: The correct answer is Glycine. Glycine is the smallest molecule among the options provided because it is a single amino acid, the basic…
Correct answer: Glycine- A. γ-1,4
- B. β-1,6
- C. β-1,4
- D. α-1,6
Explanation: In the structure of starch, branching occurs via α-1,6 glycosidic bonds.
Correct answer: α-1,6- A. α-1,4 linkages
- B. Both α-1,4 and α-1,6 linkages
- C. α-1,6 linkages
- D. All of the above
Explanation: The correct answer is that in amylose, glucose units are linked by α-1,4 glycosidic bonds.
Correct answer: α-1,4 linkages- A. Cellulose
- B. Glycogen
- C. Starch
- D. All of the above
Explanation: Cellulose is the correct answer because it is an unbranched polysaccharide consisting of a linear chain of glucose units linked by…
Correct answer: Cellulose- A. Pyranose fructose
- B. β -D glucose
- C. Furanose
- D. α -D glucose
Explanation: The correct answer is α-D-glucose. Starch is a polysaccharide made up of glucose monomers.
Correct answer: α -D glucose- A. Storage sulphur containing polysaccharide
- B. Nitrogen containing structural homopolysaccharide
- C. Mucopolysaccharide
- D. Structural oligosaccharide
Explanation: The correct answer is that chitin is a nitrogen-containing structural homopolysaccharide.
Correct answer: Nitrogen containing structural homopolysaccharide- A. Amylopectin
- B. Starch
- C. Cellulose
- D. None of these
Explanation: The correct answer is Starch. Starch is composed of two types of glucose polymers: amylose and amylopectin.
Correct answer: Starch- A. Glycogen is analogous to starch
- B. It is a structural polysaccharide
- C. It is a non-reducing sugar
- D. It gives a red color with iodine solution
Explanation: Glycogen is a storage polysaccharide found primarily in animals, stored in the liver and muscles.
Correct answer: It is a structural polysaccharide- A. Glycoproteins
- B. Flavoproteins
- C. Lipoproteins
- D. All of these
Explanation: The correct answer is Glycoproteins, as immunoglobulins (antibodies) are glycoproteins.
Correct answer: Glycoproteins- A. Keratin
- B. RuBP
- C. Rubisco
- D. Fibrinogen
Explanation: Rubisco, or ribulose-1,5-bisphosphate carboxylase/oxygenase, is the most abundant protein on Earth due to its essential role in the Calvin…
Correct answer: Rubisco- A. Haemoglobin
- B. Myosin
- C. Myoglobin
- D. Actin
Explanation: Myoglobin is the correct answer because it is a protein found in muscle tissues that stores oxygen, providing a reserve that can be used…
Correct answer: Myoglobin- A. Polyester
- B. Lipid
- C. Protein
- D. Polysaccharide
Explanation: Silk is a natural fiber that is primarily composed of the protein fibroin, secreted by silkworms.
Correct answer: Protein- A. Glucose and fructose
- B. Nucleosides and nucleic acid
- C. Nucleotides and nucleic acid
- D. Purines and pyrimidines
Explanation: The correct answer is Option C: Nucleotides and nucleic acid. Nucleotides are the monomeric units that polymerize to form nucleic acids…
Correct answer: Nucleotides and nucleic acid- A. Ascorbic acid
- B. Collagen
- C. Cellulose
- D. Galactose
Explanation: Collagen is the correct answer because it is a protein, and proteins are made up of amino acids, which are their building blocks.
Correct answer: Collagen- A. Option A
- B. Option B
- C. Option C
- D. Option D
Explanation: The question requires identifying how cellulose and sucrose are correctly characterized.
Correct answer: Option D- A. ATP
- B. DNA
- C. Collagen
- D. Maltose
Explanation: Peptide bonds are a defining feature of proteins, linking amino acids in a chain.
Correct answer: Collagen- A. Amylose
- B. Myoglobin
- C. Collagen
- D. Glycogen
Explanation: The correct answer is Glycogen. It is a polysaccharide stored in human muscles, playing a vital role in energy storage.
Correct answer: Glycogen- A. Amylase
- B. Haemoglobin
- C. Collagen
- D. Keratin
- E. C and D
Explanation: The correct answer is Option E: C and D, as both Collagen and Keratin are fibrous proteins.
Correct answer: C and D