Question

14. How does Coronavirus infect the lung tissue?

A. The S-spike protein binds to Angiotensin Converting Enzyme 2 on Type 2 alveolar cells, leading to its destruction, a reduction in surfactant and Coronavirus replication .

B. The S-spike protein binds to Angiotensinogen on Type 2 alveolar cells, leading to its destruction, a reduction in surfactant and Coronavirus replication .

C. The S-spike protein binds to Angiotensin Converting Enzyme 2 on Type 1 alveolar cells, leading to its destruction, a reduction in surfactant and Coronavirus replication .

D. The S-spike protein binds to Angiotensinogen on Type 1 alveolar cells, leading to its destruction, a reduction in surfactant and Coronavirus replication .

17. Bacteria found in our colon has the following roles EXCEPT:

A. Metaboloze undigested food, causing Gas

B. Production of Vitamin K

C. Production of Bile

D. Microbial Antagonism

Answer 1

14. Option 'A' is correct

Justification: Coronavirus is a novel infectious disease caused by chronic respiratory syndrome. The protein which contains 1,400 amino acids for the corona virus is the 'S-spiked protein' and it binds to Angiotensin converting enzyme 2 (ACE2) receptor, which acts as the specific target site for coronavirus. The studies revealed that 83% of ACE2 expressing cells were the alveolar type 2 cells and these cells serves as reservoir for the invasion of virus. So, binding of S-spiked protein to these cells leads to their destruction and it causes the replication of coronavirus, by reducing its surfactant property.

Justification for incorrect options:

• Options 'B' and 'D' are incorrect because the S-spiked protein binds to angiotensin converting enzyme 2 (ACE2) to cause the Coronavirus because it acts as target site, but NOT to the angiotensinogen (unbroken form of angiotensin enzyme). So, these options are incorrect.
• Option 'C' is incorrect because the S-spiked protein binds to ACE2 enzyme on the type 2 alveolar cells as they act as reservoir for invading virus, but not on the type 1 alveolar cells. So, this option is incorrect.

15. Option 'D' (Microbial antagonism) is NOT the role of bacteria in colon

Justification: The microbes present in the colon of intestine helps in synthesizing vitamin K, which is important for producing some blood clotting factors and prothrombin. So, microbial growth in the colon is important and hence, bacteria in colon does not have a role of antagonizing microbes.

Justification for other options:

• Options 'A' and 'B' are correct because bacteria in the colon of intestine helps in digesting and metabolizing the undigested food by creating gas and bacteria in colon has also a function of making and producing some important substances like vitamin K, which is important for blood clotting.
• Option 'C' is correct because some of the anaerobic bacteria in the colon of intestine metabolizes bile salts, which results in the production of compounds of secondary bile salts.

Thank you!