Viruses vs Bacteria Bacteria and Viruses

Viruses are not alive… They are not composed of cells They do not respond to stimuli They do not use energy for growth and development They cannot reproduce on their own

Viruses are… Particles that cause diseases such as: Common cold Influenza Measles Chicken pox Herpes Warts AIDS

Q: People infected with the human immunodeficiency virus (HIV) have an increased risk of dying from secondary infections. Which of these best explains how HIV increases the danger of secondary infections? A.HIV produces antigens that damage red blood cells. B.HIV adds genetic material from harmful microbes. C.HIV destroys helper T cells. D.HIV consumes beneficial microbes in the body.

Q: Viruses can be transmitted in a variety of ways. The virus that causes SARS (severe acute respiratory syndrome) can be transmitted when an infected person coughs or sneezes. This virus is transmitted in a manner most similar to the transmission of — A) smallpox B) AIDS C) West Nile virus D) influenza The correct answer is D

Viral Structure All viruses contain a nucleic acid (DNA or RNA) surrounded by a protein coat called a capsid. Some viruses have a second protective coating called an envelope. Glycoproteins enable a virus to bind to the surface of a cell and enter it.

Bacteria are… Microscopic, prokaryotic cells that cause diseases such as: Strep throat Tuberculosis Botulism Anthrax Pneumonia Salmonella Lyme disease

Bacteria are also Beneficial! In the environment as producers, decomposers and by converting atmospheric nitrogen into a usable form for plants In the production of food such as yogurt, sauerkraut, and some cheeses In genetic engineering In bioremediation In your intestines they aid in digestion and help make vitamin K

Bacterial Structure Because bacteria are prokaryotes and have no nucleus, the DNA (a single circular chromosome) floats freely in the cytoplasm.

Q: Bacteria are the only organisms that can – A) Obtain energy by decomposing carbohydrates B) Transform atmospheric nitrogen into ammonia C) Produce glucose from dissolved carbon dioxide D) Synthesize proteins from amino acid molecules

 Cell Wall  Can be beneficial to living things  Capsule  Plasma membrane  Have genetic material  Can cause disease  Protein coat  No cell wall  Reproduce inside a host  Most are harmful to living things