Describe the chemical composition and physical structure of an enveloped and a nonenveloped virus.
- chemical composition-the envelope usually consists of some combination of lipids, proteins, and carbohydrates; some animcal viruses are released from the host cell by an extrusion process that coats the virus with a layer of the host cell's plasma membrane; that layer becomes the viral envelope. in many cases, the envelope contains proteins determined by the viral nucleic acid and materials derived from normal host cell components
- physical structure-depending on the virus, envelopes may or may not be covered by spikes; enveloped viruses are roughly spherical
- chemical composition-just has a protein coat over it called a capsid
- from powerpoint:
- The protein coatsurrounding the nucleic acid of a virus is called the capsid.
The capsid is composed of subunits, capsomeres, which can be a single type of protein or several types.
The capsid of some viruses is enclosed by an envelope consisting of lipids, proteins, and carbohydrates.
Some envelopes are covered with carbohydrate-protein complexes called spikes.