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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- A. Lipids
- B. Proteins
- C. Polynucleotides
- D. Carbohydrates
Explanation: The correct answer is carbohydrate. Carbohydrates are organic compounds that, upon hydrolysis, yield polyhydroxy aldehydes or ketones.
Correct answer: Carbohydrates- A. Glycosidic bond
- B. Keto group
- C. Maltose
- D. Fructose
Explanation: The correct answer is the keto group. A keto group is a defining structural feature of ketose sugars, which are a type of monosaccharide.
Correct answer: Keto group- A. CO
- B. COOH
- C. HCOH
- D. HOH
Explanation: Ketoses are sugars characterized by the presence of a ketone group, represented by the carbonyl group CO.
Correct answer: CO- A. Cx (H2O)Y
- B. (CH2 O)n
- C. Cn (H₂O)n
- D. Cn (H2 O)n−1
Explanation: The correct answer is(CH₂O)n, which is the general formula for monosaccharides.
Correct answer: (CH2 O)n- A. Ribose
- B. Maltose
- C. Cellulose
- D. Glucose
Explanation: The correct answer is glucose. Glucose is the most abundant monosaccharide found in nature.
Correct answer: Glucose- A. Enzymes
- B. Coenzymes
- C. Vitamins
- D. All of these
Explanation: The correct answer is coenzymes. Ribose is a crucial component of coenzymes such as NAD+ (nicotinamide adenine dinucleotide) and FAD…
Correct answer: Coenzymes- A. 1
- B. 2
- C. 4
- D. 2/4
Explanation: A dipeptide is formed when two amino acids are joined by a single peptide bond.
Correct answer: 1- A. Hydrogen bonds
- B. Ionic bonds
- C. Disulphide bonds
- D. Both A and B
Explanation: The correct answer is Option A: Hydrogen bonds. Hydrogen bonds are crucial for maintaining the integrity of the secondary structure of…
Correct answer: Hydrogen bonds- A. Monopeptide
- B. Dipeptide
- C. Tripeptide
- D. Tetrapeptide
Explanation: The correct answer is Option B: Dipeptide. When two amino acids are joined together by a peptide bond, the resulting molecule is called a…
Correct answer: Dipeptide- A. Protein
- B. Lipid
- C. Carbohydrate
- D. Glycoprotein
Explanation: The correct answer is glycoproteins. Glycoproteins are proteins with carbohydrate groups attached and play a crucial role in cellular…
Correct answer: Glycoprotein- A. Glycoproteins
- B. Glycolipids
- C. Phospholipids
- D. All of these
Explanation: The correct answer is phospholipids. These molecules form a bilayer that serves as the fundamental structure of cell membranes, providing…
Correct answer: Phospholipids- A. Haemoglobin
- B. Fibrin
- C. Insulin
- D. Keratin
Explanation: Frederick Sanger is renowned for his groundbreaking work in determining the amino acid sequence of proteins, most notably insulin.
Correct answer: Insulin- A. - NH2 group
- B. -COOH group
- C. R-group
- D. All of the above
Explanation: The properties of amino acids are determined by their R-groups, also known as side chains.
Correct answer: R-group- A. 20
- B. 25
- C. 100
- D. 56
Explanation: The correct answer is 20. Cells use 20 standard amino acids to synthesize proteins, which are encoded by the genetic code.
Correct answer: 201015. Hemoglobin is a:
- A. Fibrous protein
- B. Coiled protein
- C. Globular protein
- D. Double coiled protein
Explanation: Haemoglobin is a globular protein, meaning it has a roughly spherical shape and is soluble in water, which allows it to transport oxygen…
Correct answer: Globular protein- A. 20
- B. 170
- C. 25
- D. 15
Explanation: The correct answer is 20. Proteins are synthesized from 20 different standard amino acids, which are encoded by the genetic code in…
Correct answer: 20- A. Intermediate
- B. Simple
- C. Globular
- D. Fibrous
Explanation: Myosin is a type of fibrous protein. It plays a crucial role in muscle contraction by interacting with actin filaments.
Correct answer: Fibrous- A. Primary structure
- B. Secondary structure
- C. Tertiary structure
- D. Quaternary structure
Explanation: The primary structure of a protein is crucial because it refers to the linear sequence of amino acids, which dictates the protein's final…
Correct answer: Primary structure- A. Rubisco
- B. Collagen
- C. Elastin
- D. Albumin
Explanation: The correct answer is collagen. Collagen is the most abundant protein in the animal world and plays a critical role in providing…
Correct answer: Collagen- A. Haemoglobin
- B. Insulin
- C. Keratin
- D. Fibrin
Explanation: The quaternary structure of a protein involves multiple polypeptide chains coming together to form a functional unit.
Correct answer: Haemoglobin