Viruses

Role of Viruses in the Environment

  • Maintains balance in the environment

  • Controls many ecological processes (nutrient cycling, algal bloom control)

  • Can help with population control of dominant host species

  • Can cause death to marine life, and the decomposing bodies provide nutrients to bacteria at the bottom of the ocean

Parts of a Virus

Ligand:

protein that sticks out of surface of virus

acts as key to recognize cell and invade it

Membrane envelope:

layer of fatty acids

usually derived from membrane of host cell

Genetic material:

Usually has DNA or RNA(retroviruses)

Capsid

Made of protein

Bacteriophage - viruses that infect bacterial cells

Lyctic cycle (How viruses reproduce)

  1. Virus approaches cell

  2. Viruses attaches to cell and inserts DNA

  3. Virus multiplies

  4. New viruses form around DNA

  5. Cell bursts open and new viruses are released

  • Viruses are obligate intercellular parasites (have to reproduce within a cell of a different organism)

HIV & AIDS

HIV infects cells of human immune system, which weakens the immune system

Currently is treated with ARVs (Anti retro viral drugs) to deacrease viral load and give immune system a chance to strengthen, however it is not a cure as it cannot destroy the virus

To prevent have safe/no sex, avoid contact with others blood (don’t share needles) and avoid substance abuse