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This section includes 15 Mcqs, each offering curated multiple-choice questions to sharpen your Protein Engineering knowledge and support exam preparation. Choose a topic below to get started.
1. |
In the ubiquitin ligase enzyme complex, the ubiquitin molecule is attached to which of its component? |
A. | E4 |
B. | E1 |
C. | E3 |
D. | E2 |
Answer» E. | |
2. |
The second and further ubiquitin molecules are added by which of the following enzymes to make the polyubiquitin chain? |
A. | E3 |
B. | E2 |
C. | E2-E3 complex |
D. | E1- ubiquitin complex |
Answer» E. | |
3. |
The first ubiquitin molecule is linked to the lysine of substrate proteins by which of the following enzymes? |
A. | E1 |
B. | E1-Ubiquitin complex |
C. | E2 |
D. | E2-E3 complex |
Answer» E. | |
4. |
Which property of lysine makes it a good candidate for linking of polyubiquitin chain? |
A. | Its hydrophobicity |
B. | Its electronegativity |
C. | Carboxyl group in the side chain |
D. | Amino group in the side chain |
Answer» E. | |
5. |
Which of the following proteins does not move quickly through the pore of proteasome? |
A. | Abnormal proteins |
B. | Misfolded proteins |
C. | Unfolded proteins |
D. | Very stable proteins |
Answer» E. | |
6. |
Which of the following proteins is also known as unfoldases? |
A. | ACC proteins |
B. | ABC proteins |
C. | AAU proteins |
D. | AAA proteins |
Answer» E. | |
7. |
The threading reaction which unfolds the target proteins as they move through the cap is not driven by ATP hydrolysis. |
A. | True |
B. | False |
Answer» C. | |
8. |
Each proteasome consists of a central hollow cylinder, known as the 20S core proteasome. |
A. | False |
B. | True |
Answer» C. | |
9. |
Each end of the cylinder of the proteasome is normally associated with a large protein complex, the 19S cap. |
A. | False |
B. | True |
Answer» C. | |
10. |
Which of the following recognizes the degradation signals on the abnormal proteins? |
A. | E4 molecules |
B. | E1 molecules |
C. | E2 molecules |
D. | E3 molecules |
Answer» E. | |
11. |
Polyubiquitin chain is linked to which amino acid of the substrate protein? |
A. | Glycine |
B. | Proline |
C. | Methionine |
D. | Lysine |
Answer» E. | |
12. |
Which of the following complex is known as Ubiquitin ligase? |
A. | E1-E3 complex |
B. | E2-E4 complex |
C. | E1-E4 complex |
D. | E2-E3 complex |
Answer» E. | |
13. |
Which of the following enzymes is the starting point of the Ubiquitin-conjugating system? |
A. | Ubiquitin ligase (E2-E3 complex) |
B. | Accessory proteins (E3) |
C. | Ubiquitin-conjugating enzyme (E2) |
D. | Ubiquitin-activating enzyme (E1) |
Answer» E. | |
14. |
ATP dependent proteases constitute how much percent of the total cell proteins? |
A. | 0.2 percent |
B. | 10 percent |
C. | 0.1 percent |
D. | 1 percent |
Answer» E. | |
15. |
The proteolytic machinery acts after the chaperones have finished their tasks. |
A. | True |
B. | False |
Answer» C. | |