Practice Questions

Interferons are signaling proteins (cytokines) released by host cells in response to viral pathogens, and they are glycoproteins.

O-linked glycosylation occurs through the covalent attachment of an oligosaccharide to the oxygen atom of serine or threonine side chains.

Viral envelope glycoproteins interact with host cell-surface receptors, mediating viral attachment and entry.

Cytochromes are electron-transporting metalloproteins whose iron center alternates between Fe2+ and Fe3+ states to transfer electrons.

LDL transports cholesterol from the liver to peripheral tissues; excess circulating LDL can oxidize and deposit in arterial walls.

The molecule develops dual properties: a hydrophobic domain anchored in the lipid bilayer and a hydrophilic domain exposed to water.

Gangliosides are abundant in nerve cell membranes, where they participate in cell signaling, myelin stability, and synaptogenesis.

Liver cells require protein synthesis to form VLDLs; blocking this prevents lipid export, causing fats to accumulate internally.

N-linked glycosylation targets the nitrogen atom on the side chain of an asparagine residue within a specific consensus sequence.

Even when bound to basic proteins, the dense phosphate backbone of the DNA molecule provides a strong net negative charge to chromatin.