Free Proteins MCQs with Answers
99 Proteins MCQs from Biology, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Proteins are polymers of amino acids joined by peptide bonds, and their function depends on primary, secondary, tertiary and quaternary structure. The topic covers fibrous and globular proteins, enzymes, antibodies, hormones and transport proteins, as well as denaturation by heat or extreme pH.
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- A. Hydrogen groups of adjacent amino acids
- B. Non-functional groups of the amino acids
- C. Carboxyl groups and amino groups
- D. Functional groups and hydrogen groups of adjacent amino acids
Explanation: The correct option is: Carboxyl groups and amino groups.Peptide bonds are formed through a condensation reaction between the carboxyl…
Correct answer: Carboxyl groups and amino groups- A. NH3
- B. CO2
- C. H2O
- D. O2
Explanation: Peptide bond formation is a condensation process which involves removal of water molecule
Correct answer: H2O- A. Fatty acids, polysaccharides
- B. Protein, amino acids
- C. Lipids, glucose
- D. None of these options is correct
Explanation: Fatty acids do not catabolize to form polysaccharides. Lipids can be catabolized to fatty acids and glycerol, not glucose.
Correct answer: Protein, amino acids- A. Polyprotein
- B. Polymerase
- C. Polyisomerase
- D. None of these options is correct
Explanation: The correct answer is a) Polyprotein. A long polypeptide that is cut up to generate several small proteins is known as a polyprotein.
Correct answer: Polyprotein- A. Protein
- B. Globular protein
- C. Functional protein
- D. Secretive protein
Explanation: An amino acid joined only by peptide bonds is the straight chain and has the primary structure of a protein.Globular protein has a…
Correct answer: Protein- A. Peripheral protein.
- B. Transmembrane proteins.
- C. Intrinsic proteins.
- D. Intracellular proteins.
Explanation: Peripheral proteins are a group of biologically active molecules formed from amino acids that interact with the surface of the lipid…
Correct answer: Peripheral protein.- A. Three
- B. Six
- C. Nine
- D. Twelve
Explanation: There are nine essential amino acids. They are essential because they cannot be made by the body. They must be taken from food.
Correct answer: Nine- A. 20
- B. 27
- C. 15
- D. All
Explanation: X-ray analysis has shown that on the average there are 27 amino acid units for each turn of the helix.
Correct answer: 27- A. Hydrogen bonds
- B. Ionic bonds
- C. Peptide bonds
- D. Glycosidic bonds
Explanation: Amino acids are linked together by peptide bonds. A glycosidic bond or glycosidic linkage is a type of covalent bond that joins a…
Correct answer: Peptide bonds- A. Primary, secondary, tertiary and quaternary
- B. Primary, secondary and tertiary only
- C. Primary and quaternary only
- D. Quaternary only
Explanation: We are told that we have 2 chains of amino acids that are forming the enzyme (since it is formed by 2 chains, we know it has a quaternary…
Correct answer: Primary, secondary, tertiary and quaternary- A. H
- B. CH2OH
- C. CH3
- D. NH2
- E. OH
Explanation: Explanation for this question will be added soon.
Correct answer: CH3- A. Between Alpha C of one monomer and Carboxyl group of another monomer
- B. Between Alpha C's of both monomers
- C. Between Alpha C of one monomer and Amino group of another monomer
- D. Between carboxyl group of one monomer and amino group of another monomer
- E. None of the above
Explanation: Explanation for this question will be added soon.
Correct answer: Between carboxyl group of one monomer and amino group of another monomer- A. 4 Polypeptide chains + 4 Heme portions
- B. 4 Polypeptide chains + 1 Heme portions
- C. 1 Polypeptide chains + 4 Heme portions
- D. 1 Polypeptide chains + 1 Heme portions
Explanation: Myoglobin is a 17-kDa protein found in cardiac and red muscle tissues for oxygen storage.
Correct answer: 1 Polypeptide chains + 1 Heme portions- A. Primary structure
- B. Secondary structure
- C. Tertiary structure
- D. Quaternary structure
Explanation: Primary structure, is simply the sequence of amino acids in a polypeptide chain.
Correct answer: Primary structure- A. Pepsinogen
- B. Casein
- C. Enzyme
- D. Collagen
Explanation: Collagen is the main structural protein in the extracellular matrix found in the body's various connective tissues.
Correct answer: Collagen- A. Elastin
- B. Keratin
- C. Collagen
- D. Histone
Explanation: Collagen is a fibrous protein that provides structural support and forms the matrix of tissues like bone and cartilage.
Correct answer: Collagen- A. Water
- B. Lipids
- C. Carbohydrates
- D. Proteins
Explanation: The most abundant organic compound in mammalian cells is protein
Correct answer: Proteins- A. Acid
- B. Base
- C. Neutral
- D. None of these
Explanation: In an acidic medium, amino acids can carry a positive charge by losing a proton (H+) from their amino group (NH2).
Correct answer: Base- A. To enable them to respond to environmental alterations
- B. To assemble the monomers to form a coordinated polymeric structure.
- C. In the case of enzymes, to improve their rate of catalysis.
- D. None of the above.
Explanation: Option A: To enable them to respond to environmental alterations: Some proteins with quaternary structure can undergo conformational…
Correct answer: To assemble the monomers to form a coordinated polymeric structure.- A. Hydrophilic
- B. Hydrophobic
- C. Basic
- D. Acidic
Explanation: In an aqueous environment, the most stable tertiary conformation of a protein is usually one in which the hydrophobic amino acids are…
Correct answer: Hydrophobic