Microbiology: Chapter 8

1. Dessication is the......

Removal of water

Addition of water

2. Heat can quickly denatures proteins, may damage the membrane by making it more fluid and denature DNA and RNA

True

False

3. A good example of dry is flaming a loop used to transfer bacteria to a petri plate

True

False

4. Dessication may help to stop growth, but doesn't necessarily kill bacteria.

True

False

5. Match the term to the definition: Sterilization

The complete destruction of all microbes on an object

The reduction or inhibition of microbial growth on non-living surface

The reduction or inhibition of microbial growth on living tissue

6. Bacteria tend to die at a fixed exponential rate, meaning X^2(squared)

True

False

7. Match the term to the definition: Disinfection

The complete destruction of all microbes on an object

The reduction or inhibition of microbial growth on non-living surface

The reduction or inhibition of microbial growth on living tissue

8. Many endospores are resistant to dessication

True

False

9. Which of these is most popular in sterilizing culture media and lab instruments?

Autoclaving

Dry heat

Purell

Antiseptics

10. Dry heat kills by oxidizing and can...

Denature protein and DNA

Slow the growth of bacteria

Inhibits growth of new bacteria

11. Freeze drying also called lyophilizaiton is the...

Simultaneous combination of freezing and heating

Simultaneous combination of freezing and addition of water

Simultaneous combination of freezing and dessication

12. Match the term to the definition: Antisepsis

The complete destruction of all microbes on an object

The reduction or inhibition of microbial growth on non-living surface

The reduction or inhibition of microbial growth on living tissue

13. Osmotic pressure treatment is the use of ____ and causes _____.

Salts, freeze drying

Ice, plasmolysis

Salts, plasmolysis

Submit

15. Halogens are which of these (as it applies to us for this class)

Earth metals

Strong oxidizing agents

Non-earth metals

Weak oxidizing agents

16. Pasteurization is the....

Short duration/high temperature treatment of food (72C for 15 seconds)

Long duration/low temperature treatment of food (12C for 3 hours)

Short duration/low temperature treatment of food (12C for 15 seconds)

Long duration/high temperature treatment of food (72C for 3 hours)

17. What are two methods of dry heat?

Incineration (combustion)

Dry ovens

Heat lamp

Natual heat source (sun)

Submit

18. This is a commonly used household disinfectant.

Sodium hypochlorite

Hypochlorous acid

Hypochlorite

Sodium hypochlorite is bleach

Explanation

Sodium hypochlorite is bleach

19. Which of these are reasons to control microbial growth? (Choose all that apply)

Prevention and treatment of infection

Prevention of infection

Is a form of secondary prevention

Prevention of food spoilage

Submit

20. Match the term to the statement: When chlorine is added to water, what forms is a strong oxidizing agent and disrupts enzymes.

Hypochlorite

Hypochlorous acid

Compressed chlorine gas

Bleach

21. Choose all those that are correct when asking how various agents harm bacteria.

Damage to cell wall

Alteration of membrane permeability

Damage to proteins and/or nucleic acids

Controlled by either physical or chemical agents

All of these

Only A, B, and C

22. Filtration is the passage of a liquid through a filter that create a filtrate (microbes), there are membrane filters that can eliminate most bacteria, however,which of these statements is something that is not true of filtration.

Filters cannot help you obtain toxins that may be present

Filters can remove toxins that could be present

Filtration can help to separate microorganisms from a liquid

23. Boiling water kills most bacteria and viruses but how long does it take to kill each of these?

10 minutes for bacteria, 15 minutes for a virus

15 minutes for a bacteria, 25 minutes for a virus

10 minutes for a bacteria, 20 minutes for a virus

5 minutes for bacteria, 20 minutes for a virus

24. Radiation helps to kill bacteria which of these types of radiation are considered "ionizing" (Choose all that apply)

Gamma rays

UV

Microwaves

X-Rays

Submit

25. Match the term to this statement: The chemical choice in treatment of swimming pools.

Hypochlorite

Hypochlorous acid

Compressed chlorine gas

Bleach

26. Radiation kills bacteria in many ways, one of these is Non-ionizing which can be which of these? (Choose all that apply)

Gamma rays

UV

Microwaves

X-Rays

Submit

27. This is used in the disinfection of public drinking water and pools (using small quantities such as 1ppm)

Hypochlorite

Hypochlorous acid

Compressed chlorine gas

Bleach