Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Microbiology > Lab Final Review - Week #6 > Flashcards

Lab Final Review - Week #6 Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

Why is the control of microorganisms so important?

A

It allows for the prevention and treatment of diseases and to inhibit spoilage of food as well as other industrial products

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is a microbicidal effect?

A

It is one that kills the microbes immediately

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is a microbiostatic effect?

A

It is one that inhibits the reproductive capacities of cells and maintains the microbial population at a constant size

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the 3 chemical methods for control of microbial growth?

A
  1. antiseptics
  2. disinfectants
  3. chemotherapeutic agents
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Antiseptics

A

chemical substances used on living tissue, they kill or inhibit the growth of vegitative microbial forms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Disinfectants

A

chemical substances used on nonliving things, they kill or inhibit the growth of vegitative microbial forms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Chemotherapeutic agents

A

chemical substances used in living tissue, they kill or inhibit the growth of microorganisms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the 5 different physical methods for control of microbial growth?

A
  1. cell-wall injury
  2. cell membrane damage
  3. alteration of colloidal state of cytoplasm
  4. inactivation of cellular enzymes
  5. interference with the structure and function of DNA
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How types of cell-wall injury can occur?

A
  1. lysis of cell wall

2. inhibition of cell wall synthesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What types of cell membrane damage can occur?

A
  1. lysis of cell membrane

2. affect on selectivity of membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What does altering the colloidal state of the cytoplasm result in?

A

It results in the denaturing of proteins, rendering them useless

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How can cellular enzymes be inactivated?

A
  1. competitvely - reversible, binds to active site, blocking substrate and preventing it from attaching
  2. non-competitively - irreversible, binds not at active site, but alters active site so that substrate is unable to bind.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the 4 factors which primarily impact the efficiency of all antiseptics and disinfectants?

A
  1. concentration
  2. length of exposure
  3. type of microbial population to be destroyed
  4. environmental conditions
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the relationship between concentration and chemical agent effectiveness?

A

The greater the conc. the more rapid death occurs. However it is important to remember that concentrations can become toxic when placed in or on living tissues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What happens to antimicrobial activity when the length of exposure of a chemical agent is increased?

A

The antimicrobial activity will increase as well

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What type of microbes are the most resistant?

A

Bacterial spores

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Which is more resistant, capsulated or non capsulated microorganisms?

A

capsulated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Which is more resistant acid fast or non-acid fast microorganisms?

A

acid facst

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Which is more resistant younger or older cells?

A

Older cells are more resistant because they are less metabolically active

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are the 3 different environmental conditions which effect the antimicrobial action of chemical agents?

A
  1. temperature -> increase in temp = increase in rate of chemical reactions
  2. pH -> deviation from neutral may increase or decrease microbicidal action
  3. type of material on which the microorganism exists -> e.g. organic material decreases microbicidal action
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is the agar plate-sensitivity method used to test?

A

The effectiveness of a chemical agent.

22
Q

Which wavelength electromagnetic radiations are capable of being microbicidal?

A

short wavelengths 300 nm and below (gamma, X rays, and UV light)

23
Q

What are the two types of ionizing radiation?

A

gamma radiation and x radiation

24
Q

What is the mechanism by which ionizing radiation is microbicidal?

A

They transfer energy through quanta (photons) to the matter through which they pass. This energy transfer causes excitation and loss of electrons

25
Q

What are the effects of ionizing radiation on cellular constituents?

A

Cells can be directly affected through loss of chemical structures or hydrogen peroxide can be produced as a result of water being ionized -> which is toxic to cells

26
Q

How is UV light capable of disinfection materials?

A

When UV light is absorbed it damages DNA via thymine dimerization, this in turn affects DNA replication.

27
Q

Why is it that x-rays can be used for sterilization but UV light cannot?

A

Because UV light has lower energy than ionizing radiation. Many different microorganims are resistant to the effects of UV light

28
Q

What are the 2 enzyme capable of repairing radiation induced DNA damage?

A
  1. excision repair system

2. light repair system

29
Q

Which types of microorganisms are most resistant to the effects of UV light?

A

yeasts and bacterial spores are the most resistant. gram + > gram - and cocci > bacilli. However viruses are the most resistant of all.

30
Q
  1. Why is it important to remember that differences and chance cause variation?
A

Because the real world varies unpredictably and there are many explanations in answer to certain trends

31
Q
  1. Can a measurement be exact?
A

Not really, practically all measurements have some errors

32
Q
  1. What is confirmation bias?
A

It is when a scientist finds evidence to support their claim but is then not critical enough to search for contrary evidence or be critical of their results

33
Q
  1. Why are bigger samples better?
A

Because it helps to reduce natural variation and measurement error in the averages

34
Q
  1. Correlation does not imply causation because…?
A

There is always the possibility of confounding variables. Perhaps the correlation is completely wrong

35
Q
  1. What does it mean to say that regression to the mean can mislead?
A

That extreme patterns in data can be due to chance or error and it is important to realized that.

36
Q
  1. What does it mean to extrapolate beyond data?
A

It is when patterns found in data are used to predict or confirm things that are related to the data. It should not be done

37
Q
  1. What is the base-rate fallacy?
A

The ability of an imperfect test to identify a condition depends upon the likelihood of that condition occurring (base-rate). The fallacy is in drawing a conclusion without taking the base-rate (likelihood of a result to occur) into account

38
Q
  1. Why are controls important?
A

They allow for further confirmation that the treatment or test did occur and minimize the possibility that the results are due to chance

39
Q
  1. Why is randomization important?
A

Because it allows for bias to be avoided

40
Q
  1. What is the difference between replication and pseudoreplication?
A

replication -> many studies replicated on independent populations
pseudoreplication -> generalization to all populations with only data of one population

41
Q
  1. Why are scientists a problem sometimes when it comes to presenting and interpreting data?
A

Because they are invested in their work and if they are trying to prove something, they may selectively report results and even exaggerate them

42
Q
  1. How is significance of results determined?
A

By performing a T-test if P (the degree of certainty as to the accuracy of the results) is greater than 0.05 than the results are not statistically significant

43
Q
  1. What does it mean to separate no effect non-significance?
A

The lack of statistically significant result does not mean their was no underlying effect, just that it was not detected

44
Q
  1. How does effect size matter?
A

large responses are more likely to be detected and are better used for making claims than small responses

45
Q
  1. What does it mean to say that study relevance limits generalization?
A

That relevance depends on the and how much they actually resemble those of the issue being considered

46
Q
  1. Feelings influence risk ______________
A

perception

47
Q
  1. Why do dependencies change the risks?
A

Because if events are interrelated than the probability of their co-occurrence is much higher than expected

48
Q
  1. Why is data sometimes dredged or cherry picked?
A

In order to support the researchers, authors, publishers (etc.) point of view regarding the subject

49
Q
  1. How do extreme measurements mislead?
A

sampling, bias, culture, measurement error etc. are all things that can occur to the variations visible in data

50
Q

Examples of specific chemicals which control microbial growth by inactivation of cellular enzymes include?

A

mercuric chloride and ammonium

Microbiology (13 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions