04-08 Immune system and disease

04-08 Immune system and disease - Biology 105 Immune System...

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Biology 105 Immune System and Disease I. Types of pathogens (disease-causing agents) A. ____________________ 1. simple, prokaryotic cell structure 2. genes made of DNA like other organisms a. main DNA is a circular molecule called the chromosome b. separate small circular DNA molecules in the cytoplasm are called ___________________ i. plasmids often contain antibiotic resistance genes ii. plasmids can be transferred from one bacterium to another, even of a different species. This can result in the evolution of very dangerous multiply ___________________ resistant bacteria. 3. Bacteria reproduce rapidly, doubling as often as every 20 minutes. At this rate, one bacterium becomes _______________________ bacteria after 4 hours. a. reproduction is slowed by _________ temperatures, hence the benefits of refrigeration 4. Having bacteria growing in or on your body is not inherently dangerous. a. Our bodies are covered, inside and out, with a bacterial "_____________", most of which are non-pathogenic, and in fact are beneficial. i. they take up space and nutrients, ________________________ the resources available to pathogens ii. gut flora aid in digestion and vitamin uptake; when killed by antibiotics ________________ is a frequent result. b. Most disease-causing bacteria secrete ___________________ into the body which cause the damage associated with the disease. Other symptoms of disease, such as __________________, are caused by the body's attempts to kill the bacteria. example: ________________ bacteria secrete 3 toxins. i. the first allows the other two the get through the human cell membrane, ii. the second causes swelling of tissues and death as cells become unable to regulate their _________________ intake, iii. and the third kills white blood cells and spills out their destructive enzymes, which then _____________________ body cells. 5. Most important characteristic of bacteria: they are killed by ___________________________. a. Antibiotics target differences between the prokaryotic bacterial cells and the eukaryotic human cells, for example possession of cell walls and their different types of ribosomes. This allows the antibiotics to kill the bacterial cell without hurting the __________________ cell. B. Viruses 1. are not considered living organisms by most biologists a. are not composed of _____________ b. have no _____________________, do not make their own energy or proteins. c. instead, they invade cells and take over their metabolic machinery. 2. Viruses do have ____________________ material, either DNA or RNA, so they have traits and can mutate and evolve. 3. Viruses consist of a DNA or RNA core inside a protein coat and sometimes a membrane derived from the host cell. 4. viral life cycle
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04-08 Immune system and disease - Biology 105 Immune System...

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