Question 2: Compartmentalization and vesicular trafficking
i. BMPRII is a glycosylated membrane protein. State where in the cell, this protein was glycosylated. (1 mark)
ii. Explain how a newly synthesised polypeptide chain is transferred to the region in the cell where glycosylation occurs and how it moves from there to the plasma membrane. (9 marks)
COVID-19 belongs to a broad family of viruses called Coronaviruses, causing severe acute respiratory syndrome (SARS). Recent research illustrated that the SARS-CoV-2 spike protein (ligand) binds to its plasma membrane specific receptor (ACE2) via its Receptor-binding domain.
i. Please state two (2) reasons why COVID19 cannot be classified as a cell. (2 marks)
ii. From your knowledge of vesicular trafficking, name a mechanism by which COVID-19 virus can enter the cell after it binds to the ACE2 receptor on the host’s plasma membrane. (1 mark)
iii. Explain this mechanism. (7 marks)