Quiz - Sessions 4 and 5

They are inert particles that are passively taken into the cell and play no role in genome delivery

They are not metastable

They are spring loaded to uncoat and deliver the genome in the right cell

The subunits are permanently bonded together

They can never be taken apart

Virus particles are constructed with many copies of few proteins

Viral proteins have structural properties that permit regular and repetitive interactions among them

Each subunit may have 'identical' bonding contacts with its neighbors

Bonding contacts among subunits are usually non-covalent

All answers are correct

Poliovirus

Adenovirus

Herpesvirus

Parvovirus

Influenza virus

The receptor may uncoat the viral genome

Some enveloped viruses fuse with the plasma (external) membrane

Low pH in the endosome activates viral fusion glycoproteins

The outer capsid shell may be removed after endosomes fuse with lysosomes

All answers are correct

By hiding the fusion peptide near the viral membrane

Cleavage of fusion proteins by cellular proteases

Low pH exposes the fusion peptide

Binding of a viral glycoprotein to a fusion receptor in the endosome membrane

All answers are correct

The influenza virus HA contains a receptor-binding pocket at the tip that binds amino acids of the cellular receptor

Receptors are needed because virus particles are too large to diffuse across the plasma membrane

Different viruses may bind the same receptor molecule

Some viruses require more than one receptor molecule for cell entry

Some virus particles are too large to move intact through the nuclear pore complex