A virus is made up of a core of genetic material, either DNA or RNA, surrounded by a protective coat called a capsid which is made up of protein.

What are viruses made of?

Viruses are infectious agents that are composed of genetic material (DNA or RNA) enclosed in a protein coat called a capsid. Some viruses also have an outer envelope made of lipids that covers the capsid. The structure of a virus is relatively simple compared to other living organisms.

The Capsid of a Virus

The capsid is a protective shell made of protein subunits called capsomeres. The capsomeres fit together like a puzzle to form the capsid. The capsid protects the virus's genetic material and helps the virus infect host cells.

The Envelope of a Virus

Some viruses have an outer envelope made of lipids that covers the capsid. The envelope is derived from the host cell's plasma membrane or internal membranes. Viruses with envelopes are called enveloped viruses. The envelope is essential for the virus to enter and exit host cells.

The Genetic Material of a Virus

The genetic material of a virus can be either DNA or RNA. The genetic material is enclosed in the capsid or located inside the envelope. Some viruses have single-stranded RNA or DNA, while others have double-stranded RNA or DNA.

The Functioning of a Virus

Viruses are not living organisms because they cannot reproduce on their own. They need a host cell to replicate and spread. Once a virus enters a host cell, it uses the host's cellular machinery to reproduce its genetic material and produce new virus particles. The new virus particles then exit the host cell, either by budding off the plasma membrane or by lysing the cell.

In conclusion, viruses are composed of genetic material (DNA or RNA) enclosed in a protein coat called a capsid. Some viruses also have an outer envelope made of lipids that covers the capsid. The structure of a virus is relatively simple compared to other living organisms. Viruses are not living organisms because they cannot reproduce on their own and need a host cell to replicate and spread.