1 / 16

Viruses and Bacteria

Viruses and Bacteria. Chapter Two. Viruses. Characteristics of a Virus Tiny non-living particle that enters and then reproduces inside a living cell. 2. Viruses can multiply, but only as a parasite (causing harm) inside a living cell (host). B. Virus Shape

royce
Télécharger la présentation

Viruses and Bacteria

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Viruses and Bacteria Chapter Two

  2. Viruses • Characteristics of a Virus • Tiny non-living particle that enters and then reproduces inside a living cell. 2. Viruses can multiply, but only as a parasite (causing harm) inside a living cell (host).

  3. B. Virus Shape -wide variety of shapes such as round, rod, bricks, bullets, or robots. 1.Bacteriophage- “bacteria eater” virus that harms a bacteria cell. (See worksheet for diagram and pg.43 in book for round virus). 2.Scientists name viruses after the disease they cause, or the people who find them.

  4. C. The Structure of Viruses 1. Protein Coat-protects the virus and is important in the invasion of other cells. 2. Genetic Material- injects into the cell and allows it to reproduce.

  5. D. Virus Multiplication (reproduction) 1. Attaches to the living cell 2. Injects the genetic material 3. Genetic material reproduces 4. New Viruses assemble 5. Cell bursts open releasing new viruses.

  6. Bacteria • Cell Structure- single celled organism with genetic material not in a nucleus. 1. Cell wall- rigid for protection 2.Cytoplasm- gel-like material holding the genetic material in the cell.

  7. 3. Ribosome-chemical factories where proteins are produced. 4. Flagellum-whip-like structure that helps a cell to move. B. Cell Shapes- rod, sphere, spiral

  8. C. Obtaining Food- 1. Autotrophs-some bacteria can use the sun’s energy to make their own food. 2. Heterotrophs-some bacteria obtain energy from their environment.

  9. D. Respiration-some bacteria need oxygen, for others, oxygen is poison. E. Reproduction-need food, the right temperature, moisture

  10. 1.Asexual Reproduction-Binary Fission involving only one parents where the offspring are identical. The cell duplicates, then dies. 2.Sexual Reproduction-Two parents who combine their genetic material during conjugation-transfers the DNA.

  11. 3. Endospore Formation- Small round thick walled resting cell that forms inside the bacteria until conditions are right for reproduction. Bacteria can survive freezing, heating, and drying for many years.

  12. F. Role of Bacteria in Nature- 1. Oxygen Production- bacteria have contributed to the Earth’s atmosphere. 2. Food Production- Cheese, sauerkraut, pickles, yogurt, buttermilk, sour cream, etc. during pasteurization food is heated to kill bacteria. 3. Recycling- Decomposers break down dead organisms into their nutrients.

  13. 4. Environmental Clean up- Oil eating bacteria for oil spills 5. Health and Medicine- Insulin making bacteria.

  14. III. Viruses, Bacteria, and your Health • Infectious Diseases- pass from one organism through: • Contact with an infected person • A contaminated object • Infected animal • Environmental source

  15. B. Treating Infectious Diseases 1. Bacterial diseases can be treated with antibiotics that kill bacteria without harming a person’s cells. Examples: Lyme Disease, Tuberculosis, Tetanus (lockjaw), Food Poisoning, Strep Throat

  16. 2. Antibiotic resistance- results when some bacteria are able to survive in the presence of antibiotics. 3. Virus Diseases- there are currently no medications to kill viruses. a. Influenza, Hepatitis C, Chicken pox, Acquired Immuno-Deficiency Syndrome (AIDS)

More Related