What are Viruses?

Viruses are tiny infectious agents made up of genetic material (either DNA or RNA) enclosed in a protein coat called a capsid. Some viruses also have an outer lipid envelope. They are much smaller than bacteria and cannot reproduce or carry out metabolic processes on their own. Instead, viruses must infect a host cell and use its machinery to replicate.

Key Characteristics:

Structure: Most viruses consist of a nucleic acid core (genetic material), a protein coat, and sometimes a lipid envelope.
Non-Living: Viruses are considered non-living because they cannot reproduce independently or maintain metabolic processes without a host.
Host Specificity: Viruses can infect a variety of organisms, including humans, animals, plants, fungi, and even bacteria (bacteriophages).

How Viruses Work:

Attachment: The virus binds to specific receptors on the surface of the host cell.
Entry: The virus or its genetic material enters the host cell.
Replication: The host cell’s machinery is hijacked to replicate the virus’s genetic material.
Assembly: New viral particles are assembled.
Release: The new viruses are released, often destroying the host cell in the process, and go on to infect other cells.

Examples of Viruses:

Influenza Virus: Causes the flu.
Human Immunodeficiency Virus (HIV): Causes AIDS.
SARS-CoV-2: The virus responsible for COVID-19.
Herpes Simplex Virus (HSV): Causes oral and genital herpes.

Viruses can cause a range of diseases, but not all are harmful. Some viruses are even being explored for their use in gene therapy and cancer treatments.