BRAINCAKEThe Structure of Viruses
All viruses share the same basic plan: a core of nucleic acid protected by a protein coat. Some also have an outer envelope.
Nucleic acid. The genome may be DNA or RNA, and it may be single-stranded or double-stranded. It carries the genes needed to make new virus particles, and is usually very small, with only a few genes to a few hundred genes.
Capsid. The protein coat is the capsid. It is built from many identical protein subunits called capsomeres, which fit together in a regular pattern. The capsid protects the nucleic acid and, in many viruses, carries the attachment proteins that bind to receptors on the host cell. The nucleic acid plus capsid is called the nucleocapsid.
Sign in free to see the rest of this lesson, the R.E.C.I.P.E. recall steps and the quiz
BrainCake is free. Make an account in seconds and pick up where this page stops.
Key terms in this lesson
- reverse transcriptase
- A viral enzyme that synthesises DNA from an RNA template, used by retroviruses such as HIV.
More in Prokaryotic Cells
- Gram-Staining
- Antibiotics
- Alternative Classification of Bacteria
- Viruses
- DNA Viruses
- RNA Viruses
- RNA Retroviruses
- Viral Reproduction
All 31 lessons in Prokaryotic Cells · All Edexcel AS-level Biology topics