viruses

Describe the structure of a virus (genetic material, capsid, envelope)

Viruses either have DNA/RNA as their genetic material, so it can either be double stranded or single stranded

A protein coat called a capsid surrounds the genetic material. The capsid is made up of protein subunits called capsomers.

Some viruses have an outer lipid envelope which came from the host cell membrane.

How do viruses replicate?

• virus attaches to specific receptor on surface of host cell

• Fuse with cell membrane

• Inside it releases it genetic material

• Viral genome and virtual genes are transcribed

• New virus particles are formed and released from host cell

What are viroids?

Smaller infectious agents composed of a short circular RNA molecule.

Cause disease in plants

What are prions?

Misfolded proteins that cause normal proteins to also adopt the abnormal structure/