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CHAPTER 18: BACTERIA & VIRUSES

Bacteria

 

 

Prokaryotes Eukaryotes
     
     
     

  

Bacteria exist in 3 different shapes:

Rod Spherical (Round) Spiral
 

 

  

 

 

 

  

     
Exanples: Examples: Examples:

 

 

Traits of Prokaryotes (Bacteria): 

 

Bacteria Can Be Classified According to these 3 things:

 

 

 

 

 

Bacteria Can have 2 different types of cell walls:

 

1.          _________________________________________________

 

 

 

 

 

 

 

2.          ________________________________________________

 

 

 

 

 

 

__________________________________ - A special staining procedure that reveals the chemical difference between the 2 types of bacterial cell walls.

 

This staining procedure is important in diagnosing diseases caused by bacteria because:

 

 

 

Bacteria Reproduce by:

 

1.          ____________________________________________ -

 

 

 

 

 

2.          _____________________________________________ -

 

 

 

 

Bacteria reproduce __________________.

 

 

Bacterial Nutrition

Bacteria are successful because they can use a wide variety of foods.

 

 ____________________________: Converting light energy into food molecules

 ____________________________: Making complex organic molecules from energy in inorganic molecules, such as ammonia or methane. 

  

Most bacteria are ______________________, they feed off of living things, causing disease.

 

 

HOW BACTERIA AFFECT HUMANS

 Beneficial Bacteria:

 

1.          ____________________________________________ - Return nutrients to the environment by breaking down organic matter, releasing CO2, N, P, S, H2O, nutrients that plants need to grow.

 

2.          ______________________________________________ - Convert atmospheric nitrogen to ammonia (a Nitrogen compound that plants can absorb)

 

3.          ______________________________________________ - Adds flavor to foods (cabbage -> sauerkraut, cucumbers-> pickles); produce dairy products (yogurt, sour cream); produce insulin & antibiotics

 

Harmful Bacteria:

 

1.          ______________________________________________ - Disease-causing bacteria. They cause damage to hosts’ tissues, may be transmitted through the air, and produce toxins that attack cells.

 

2.          ____________________________________________ - Bacteria ferment sugars on teeth -> lactic acid is produced -> loss of calcium -> break down of proteins in tooth enamel

 

3.          ______________________________________________ - Stress creates an environment beneficial to bacterial growth.

 

4.          ______________________________________________ - Botulism, Salmonella, E. coli, Cholera are examples of bacteria spread in this fashion.

 

To prevent contamination:

 

  

 

Bacteria can be spread through the air (examples): Tuberculosis, diptheria, whooping cough

Prevention & Control of Bacterial Disease

 

 

 

 

 

(Refer to figure 18-11 to see how a vaccine works)

 

 

 

 

 

 

            Examples of antibiotics: Penicillin, Tetracyclin, Streptomycin

 

Bacterial Resistance to Antibiotics

 

Many bacteria are becoming resistant to antibiotics because of _______________ and ________________ of antibiotics.

 

Bacteria acquire resistance through:

 

 

 

Refer to figure 18-13.

 

  

 

 

VIRUSES

Microscopic particles that invade the cells of plants, animals, fungi & bacteria. They usually destroy the cells they invade.

  

Traits of Viruses 

 

Viruses are not considered to be Alive because:

 

 

If viruses are not living things, then why do we study them in biology?

 

 

Tour of an AIDS Virus (p. 346) 

 

How viruses Reproduce (Life cycle of the HIV Virus) (fig 18-15) 

 

 

 

 

 

HIV destroys large numbers of ____________ that fight _______________ in the body. In early stages, only _____________ symptoms appear. Within 10 years, T-cell levels can drop drastically. When T-cell levels have gone below __________, a person is said to have “AIDS,” Acquired Immunodeficiency Syndrome.” Patients die of ________________  __________________that their bodies cannot fight due to lack of defense from the _____________ system, more specifically from _______________.

 

 

Diseases Cause by Viruses

 

Viral Disease Transmitted by Symptoms
        
        
        
         
        
        
        
        
        
        
                

 

Defense Against Viruses

 Antibiotics cannot be used to treat viruses because:

 

Effective Treatments include: 

 

Vaccines do not protect against ALL viruses 

___________, ____________ virus & ___________ virus have surface proteins whose genes constantly _______________ & ______________. _____________ system does not recognize new surface proteins and cannot fight the mutated virus.

 

    

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