Summary of "Viruses (Updated)"
Scientific Concepts and Discoveries
Viruses vs. Living Organisms: Viruses are not classified as living things because they lack cellular structure and characteristics of life. They are much smaller than cells and require a host for replication.
Structure of Viruses
- Composed of genetic material (DNA or RNA).
- Surrounded by a protein coat (capsid).
- Some have additional structures like enzymes or an outer envelope.
Viral Replication Cycles
- Lytic Cycle:
- Virus attaches to a host cell and injects its genetic material.
- The host cell replicates the viral components, leading to cell lysis (bursting) and the release of new Viruses.
- Lysogenic Cycle:
- Virus injects its genetic material, which integrates into the host's DNA and remains dormant.
- The viral genetic material replicates with the host's DNA until triggered to enter the Lytic Cycle.
Implications of Viral Infections
- Common colds are caused by Viruses, which cannot be treated with antibiotics.
- HIV targets immune cells (Helper T cells), making infected individuals vulnerable to other infections.
- Antiviral medications exist to slow HIV replication, but mutations in the virus can complicate treatment.
Positive Aspects of Viruses
- Viruses can play a role in gene therapy.
- Some Viruses can target pest insects, potentially serving as alternatives to chemical pesticides (e.g., Nuclear Polyhedrosis Virus).
Researchers or Sources Featured
- Amoeba Sisters (YouTube channel)
Category
Science and Nature
