Key Features of Viruses
- Viruses are non-cellular particles that infect living cells
- Note that viruses are not cells, and they are not considered to be living organisms, so are referred to as 'particles'
- They are much smaller than prokaryotic cells, with a diameter of 20-300 nm
- Structurally they have
- A nucleic acid core made of either DNA or RNA
- A protein coat called a capsid
- Some viruses have an outer layer called an envelope; this forms from the membrane phospholipids of the host cell in which they were produced
- Viruses can only reproduce by infecting living cells and using their protein-building machinery to produce new viral particles
- Viruses use attachment proteins on their surface to bind to and infect their host cells
Virus structure diagram
Basic virus structure includes a protein capsid and a nucleic acid core
