Viruses are bundles of genetic material wrapped in a protein coat that can infect living things. Viruses cause damage by hijacking a host cell’s machinery to make copies of themselves, often disrupting normal cell function.
What is a virus?
Viruses are tiny infectious particles that are halfway between living and nonliving organisms. They are so small (a millionth of a millimeter) that it would take hundreds to thousands of them to cover the end of a human hair. Each virus is composed of genetic material wrapped in a protein coat. Viruses that infect plants and animals also have a layer of fat molecules. Viruses cannot reproduce on their own. Instead, viruses replicate by infecting a host cell (such as humans, other animals, plants or bacteria), hijacking the host’s biological machinery and turning the host cell into a virus-producing factory.
What are viruses made of?
Most viruses have the same basic structure:
- a genetic information molecule in the form of nucleic acids such as DNA or RNA.
- a protein layer, or coat, that surrounds and protects the nucleic acids.
The protein layer allows viruses to fuse with the outer layer of the cells they attack. The nucleic acid portion encodes genes to make proteins that are essential for the virus to function. These proteins direct viral replication and carry out other activities, such as evading host defenses…
Source: National Human Genome Research Institute – National Institutes of Health
Fact Sheets about Genomics
The National Human Genome Research Institute (NHGRI) has produced this series of fact sheets to explain complex concepts in genomics research to a non-scientific audience. Teachers, students and the general public alike will find the materials clearly written and easy to understand. – Check it out…