Biochemistry Multiple Choice Questions on “Protein Tertiary and Quaternary Structures”.
1. Fibroin is rich in ________
A. Alanine and Glycine
B. Alanine
C. Glycine
D. Pro
Answer: A
Clarification: Fibroin is rich in Alanine and Glycine residues, permitting a close packing of β sheets and an interlocking arrangement of R groups.
2. Which of the following bonds are not involved in tertiary type of protein structure?
A. Disulfide bond
B. Hydrogen bonding
C. Salt bridges
D. Hydrophilic interactions
Answer: D
Clarification: Hydrophobic interactions are present in tertiary type of protein structure.
3. Which of the following does not possess a quaternary structure?
A. Myoglobin
B. Lactate dehydrogenase
C. Immunoglobin M
D. Creatine Phospho Kinase
Answer: A
Clarification: Myoglobin is a monomer, so it does not possess a quaternary structure.
4. Which of the following is abundantly found in collagen?
A. Glycine
B. Serine
C. Alanine
D. Tryptophan
Answer: A
Clarification: Each three amino acids of the collagen peptide chain is a glycine. It is thus an abundant amino acid that is important for collagen structure.
5. Which of the following is first determined as oligomer?
A. Myoglobin
B. Collagen
C. Keratin
D. Hemoglobin
Answer: D
Clarification: Hemoglobin contains four polypeptide chains and four heme prosthetic groups in which iron atoms are present in Fe+2 state.
6. Which of the following is false?
A. Lysozyme has S-S linkage
B. Ribonuclease has S-S linkage
C. Heme group in cytochrome c is covalently linked to the protein on two sides
D. Ribonuclease has SH-SH linkage
Answer: D
Clarification: Lysozyme and ribonuclease have disulfide linkages.
7. Which of the following enzyme is secreted by the pancreas?
A. Ribonuclease
B. Lysozyme
C. Cytochrome c
D. Myoglobin
Answer: A
Clarification: Ribonuclease is secreted by the pancreas into small intestine, where it catalyses the hydrolysis of certain bonds in ribonucleic acids present in the ingested food.
8. Which of the following is a component of mitochondria?
A. Ribonuclease
B. Lysozyme
C. Cytochrome c
D. Myoglobin
Answer: C
Clarification: Cytochrome c which is a heme protein is a component of the respiratory chain of mitochondria.
9. Which of the following serves as bactericidal agent?
A. Ribonuclease
B. Lysozyme
C. Cytochrome c
D. Myoglobin
Answer: B
Clarification: Lysozyme can lyse, or degrade bacterial cell walls, so it serves as a bactericidal agent.
10. Which of the following is false about fibrous protein?
A. It is in rod or wire like shape
B. Keratin and collagen are the best examples
C. Hemoglobin is the best example
D. It provides structural support for cells and tissues
Answer: C
Clarification: Hemoglobin is the best example of globular protein.
.