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. Glycine and Glycine
- B. Glycine and Alanine
- C. Alanine and Alanine
- D. Glycine and Valine
Explanation: A dipeptide glycylalanine consists of the amino acids glycine and alanine.
Correct answer: Glycine and Alanine- A. 21, 30
- B. 20, 31
- C. 31, 20
- D. 22, 29
Explanation: Short chain of insulin consists of 21 amino acids whereas long chain consists of 30 amino acids.
Correct answer: 21, 30- A. Peptide bonds
- B. Hydrogen bonds
- C. Disulphide bond
- D. Glycosidic bonds
Explanation: Disulphide bonds hold together the two chains of amino acids.
Correct answer: Disulphide bond- A. Disulphide bonds
- B. Hydrogen bonds
- C. Hydrophobic interaction
- D. Peptide bonds
Explanation: The primary structure of proteins is stabilized by peptide bonds. Peptide bonds are the bonds that link amino acids together to form a…
Correct answer: Peptide bonds- A. 151 amino acids
- B. 146 amino acids
- C. 141 amino acids
- D. 156 amino acids
Explanation: Each alpha chain of hemoglobin consists of 141 amino acids.
Correct answer: 141 amino acids- A. 146 amino acids
- B. 156 amino acids
- C. 141 amino acids
- D. 151 amino acids
Explanation: Each beta chain of hemoglobin consists of 146 amino acids.
Correct answer: 146 amino acids- A. 574
- B. 570
- C. 572
- D. 573
Explanation: 574 as 141×2= 282 and 146×2= 292 then 282+292-574
Correct answer: 574588. Number of peptide bonds involved in maintenance of primary structure of shorter chain of insulin is:
- A. 30
- B. 21
- C. 20
- D. 19
Explanation: Shorter chain of insulin consists of 21 amino acids, thus having 20 peptide bonds.
Correct answer: 20- A. Number of amino acids
- B. Type of amino acids
- C. Number and type of amino acids
- D. Number and sequence of amino acids
Explanation: The primary structure of protein is determined by number and sequence of amino acids.
Correct answer: Number and sequence of amino acids- A. 10,000
- B. 1000
- C. 10,0000
- D. 100
Explanation: In human body all the proteins are synthesized from same twenty amino acids however their diversity depends upon number and sequence of…
Correct answer: 10,000- A. Shape
- B. Functional capacity
- C. Oxygen carrying capacity
- D. Quaternary level
Explanation: By changing sequence of amino acids in a quaternary protein the structure and function of proteins is changed but it will remain a new…
Correct answer: Quaternary level- A. Quaternary
- B. Tertiary
- C. Secondary
- D. Primary
Explanation: Any change in hemoglobin at primary level changes the overall configuration of hemoglobin and as a result it stops functioning properly.
Correct answer: Primary- A. α-helix
- B. β-helix
- C. α-pleated sheet
- D. β-pleated sheet
Explanation: Alpha helix is also called a classic Pauling-Corey-Branson α-helix. The 3.613 is also used for this type of helix denoting the average…
Correct answer: α-helix- A. Ionic bond
- B. Peptide bond
- C. Hydrogen bond
- D. Disulphide bond
Explanation: The coils and folds of secondary structure are stabilized by hydrogen bonds between consecutive folds or turns /coils.
Correct answer: Hydrogen bond- A. Ionic bonds
- B. Hydrogen bonds
- C. Disulphide bonds
- D. Hydrophobic interaction
Explanation: Hydrophobic amino acids are buried inside while the hydrophilic amino acids are on the surface of the molecule until the aqueous medium…
Correct answer: Hydrophobic interaction- A. Ionic bonds
- B. Hydrophobic interaction
- C. Hydrogen bonds
- D. Ionic bonds, Hydrogen bonds and Hydrophobic interaction
Explanation: Quaternary structure is maintained by ionic bonds, hydrogen bonds, and hydrophobic interactions.
Correct answer: Ionic bonds, Hydrogen bonds and Hydrophobic interaction- A. Primary structure
- B. Secondary structure
- C. Tertiary structure
- D. Quaternary structure
Explanation: A hemoglobin molecule stands at quaternary level of proteins. It involves four chain of tertiary level i.e.
Correct answer: Quaternary structure- A. Keratin
- B. Hemoglobin
- C. Enzyme
- D. Antibodies
Explanation: Keratin is that structural protein which is used to make our hair and nails and all structural proteins including keratin are included in…
Correct answer: Keratin- A. Keratin
- B. Fibrin
- C. Collagen
- D. Hemoglobin
Explanation: All functional proteins are globular proteins including hemoglobin.
Correct answer: Hemoglobin- A. 3.4 Ao
- B. 34 Ao
- C. 0.34 Ao
- D. 340 Ao
Explanation: Dividing 34 A0 (3.4 nm) by 10, we get 3.4 A0 or 0.34 nm.
Correct answer: 3.4 Ao