EOG REVIEW 8 th grade SCIENCE

1. EOG REVIEW 8th grade SCIENCE

2. GOAL 7 Microbiology BACTERIA VIRUSES

3. microorganism a very small organism that can be seen only with a microscope EXAMPLE: bacteria

4. bacteria a large group of one-celled organisms without nuclei that sometimes cause disease

5. bacteria All bacteria are single cells without nuclei. All bacteria are prokaryotic cells.

6. Shapes of Bacteria -Streptococcus(strep throat) -Staphylococci ("staph“ infections) COCCI: sphere-shaped -sometimes grow in chains or in clumps like a bunch of grapes -can also form in chains -some types have whiplike structures called flagella to help them move around. BACILLI: rod-shaped -E.coli(found in the intestines of mammals) -Salmonella(food poisoning) -can use their shape to propel themselves by twisting like a corkscrew SPIRILLA: spiral-shaped -Borrelia burgdorferi(Lyme disease)

7. BACTERIAL GROWTH • Bacterial growth is the division of one bacterium into two daughter cells in a form of asexual reproduction called binary fission.

8. BACTERIAL GROWTH • Bacterial growth is an increase in population size NOT an increase in the size of a single bacterium. • Bacterial growth proceeds exponentially until the environment can no longer support the growth or deaths of bacterial cells begin. E. coli bacteria undergoing binary fission. The cell wall is dividing resulting in the formation of two cells.

9. BACTERIAL GROWTH CURVE 4 3 1 2 • Microbial Growth Cycle • 1) LAG PHASE • Interval of time between when a culture is inoculated and when bacterial population growth begins. • 2) Exponential phase • Cells in this phase are typically in the healthiest state. Growth of bacterial population is at maximum rate. • 3) Stationary phase • Growth rate of bacterial population is zero. • Number of new cell divisions = Number of cells dying • 4) Death phase • Lack of nutrients and increasing accumulation of wastes cause--- • Number of cell deaths > Number of new divisions

10. BACTERIAL GROWTH CURVE

11. BACTERIAL GROWTH RATE • Growth rate varies depending on environmental conditions. • Different microbes have different growth rates. • EXAMPLES: • Mycobacterium leprae = 10-30 days • Staphylococcus aureus = 20-30 minutes Bacteria Divide and Multiply Bacteria Growth Rate

12. producer • an organism that captures energy from sunlight and transforms it into chemical energy that is stored in energy-rich carbon compounds • a source of food for other organisms

13. decomposer an organism that feeds on and breaks down dead plant or animal matter

14. decomposer Decomposers include: 1) bacteria 2) fungus-like protists (molds) 3) worms 4) insects

15. parasite an organism that absorbs nutrients from the body of another organism, often harming it in the process

16. host cell a cell that a virus infects and uses to make copies of itself

17. virus • a nonliving, • disease-causing particle that uses the materials inside cells to reproduce • consists of genetic material enclosed in a protein capsid (protein coat)

18. virus POLIO VIRUS

19. MAKING NEW VIRUSES 5 Steps to Make a New VIRUS / DESCRIPTION 1) ATTACHMENT- virus attaches to surface of a cell 2) INJECTION- virus injects its DNA into the cell 3) PRODUCTION- using same machinery used by host cell for copying its own DNA, host cell makes copies of viral DNA 4) ASSEMBLY- viral DNA forces infected cell to assemble news viruses from parts it created 5) RELEASE- cell bursts open, releasing 100+ new viruses

20. The most common viral diseases are colds and influenza (flu). Cold and flu viruses are spread through the air, on surfaces, and by contact with infected persons.

21. PROPERTIES • unicellular • some form chains or clumps • no nucleus • genetic material floats freely in cytoplasm • no organelles (other than ribosomes) • reproduce by binary fission • (1 cell divides into 2 cells) • cell membrane and cell wall • some have flagella • pathogenic- can cause disease • nonliving • genetic material enclosed in protein coat • must infect living • host cell to reproduce • pathogenic- can cause disease • unicellular (most) • multi-cellular (some) • nucleus containing genetic material • live in moist environments • variety of organelles: • 1) vacuoles 2) mitochondria 3) chloroplasts • some have flagella • or cilia • 3 major groups: • 1) plant-like • (algae) • 2) animal-like (protozoa) • 3) fungus-like (decomposers) • pathogenic- can cause disease

22. IMAGES- BACTERIA spirilla cocci bacilli BACTERIA CAM BINARY FISSION

23. IMAGES- VIRUS bacteriophage Oh Goodness!!! My E. coli has a Virus!

24. pathogen • agents that cause disease • comes from the Greek word pathos, which means "suffering"

25. mutagen • ORIGIN- Latin meaning origin of change • an agent that changes the genetic material (usually DNA) of an organism and thus increases the frequency of mutations • Mutagens can be carcinogenic (able to cause cancer)

26. antigen • foreignsubstance that prompts the generation of antibodies and can cause an immune response to avoid infection, disease, or other unwanted biological invasion

27. antibiotic • a substance that can destroy bacteria • first discovered in 1928 when scientist Alexander Fleming was performing experiments on bacteria

28. antibiotic

29. Vaccines are the best way to prevent people from getting sick from viral infections. Vaccines are made from parts of a virus. They allow our bodies to see a virus in a form that won't make us sick. Then when our bodies see the virus again it recognizes and fights the virus. If you do get sick from a virus, your doctor may use an antiviral drug to help you get better. Antibiotics do not work on viruses! Antibiotics kill only bacteria. VACCINES

30. VACCINES Vaccines can also be made to prevent bacterial diseases such as whooping cough and tetanus.

31. VACCINES A terrible viral disease called small pox used to exist. The small pox vaccine was very widely used and now small pox has been eliminated! There have been no cases of small pox reported since 1977. In 1796, Edward Jenner made the first vaccine for smallpox.

32. infectious disease • diseases caused by pathogens EXAMPLES: bacteria, viruses • diseases that can be transmitted or spread from one organism to another

33. infectious disease • Infectious diseases are called • CONTAGIONS.

34. noninfectious disease diseases that cannot be spread by pathogens

35. resistance the ability of an organism to protect itself from a disease or the effects of a substance

36. 3 diseases caused by bacteria: - pneumonia - food poisoning - strep throat

37. 3 sicknesses caused by viruses: - influenza (flu) - chicken pox - colds

38. Alexander Fleming discovered penicillin (1928)

39. Alexander Fleming - performing experiments on bacteria - found mold growing on his bacteria samples (accidental) - area around mold was clear of bacterial colonies - concluded that something in mold killed bacteria

40. vector insects and animals that spread diseases to humans EXAMPLES Deer ticks are the vector of Lyme disease (bacterial). Mosquitoes are the vector of the West Nile disease (viral).

41. carrier people who are infected with a disease and can infect others but do not show symptoms of the disease themselves

42. THE END