Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Microbio - LSCI 230 > Chapter 5 - Microbial Growth > Flashcards

Chapter 5 - Microbial Growth Flashcards

1
Q

nutrients in which metabolism is simple

A

N, S, P

only slight modifications are needed before incorporating into cellular material

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

sources in which many transformations must be done during metabolism

A

carbon and energy

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

what is a macronutrient

A

required in large amounts

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

examples of macronutrients

A

Carbon, Nitrogen, Hydrogen, Oxygen, Phosphate, Sulfur, Potassium, Magnesium, Calcium, Sodium

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

what is a muicronutrient

A

required in trace amounts

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

examples of micronutrients

A

iron and trace metals

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

what is a growth factor

A

molecules that a microorganism needs for growth but cant synthesize by itself. can be byproduct or waste of another microbe

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

examples of growth factors

A

vitamins, amino acids, purines, pyrimidines, other organic molecules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

how to most prokaryotes multiply

A

binary fission

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

what is binary fission

A

cells grow in size until it forms a partition that constricts the cell into 2 daughter cells

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

true or false: daughter cells are able to exist independently immediately after creation

A

true

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

what do daughter cells receive from the mother cell

A

daughter cell receives one copy of the chromosome, ribosomes, macromolecules, monomers, and other necessary molecules to exist independently

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what must happen in order for cell division to occur

A

destroying of the cell wall and peptidoglycan to change the size of the cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what exports NAM and NAG peptidoglycan subunits across the cytoplasmic membrane

A

bactoprenol

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

2 things cell division requires

A
  1. synthesis of new cell wall material

2. destruction of cell wall material by autolysins

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

when does bactoprenol fuction

A

during synthesis of new cell wall

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

what is FTsZ ring

A

the division ring

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

what are autolysins

A

bacteriolytic enzymes that digest and synthesize the peptidoglycan of the cell wall

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

how do autolysins function

A

they create gaps in the peptidoglycan at the division ring to allow rearrangement and synthesis of a new cell wall

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

what is a wall band

A

scar between old and new peptidoglycan

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

true or false: the mechanism for division of archaea with a cell wall is very different from that of bacteria

A

false

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

how is macconkey selective

A

it contains bile salts that inhibit G+ (ALLOW G-)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what does macconkey differentiate between and by what colors

A

lactose fermenters - pink

lactose non-fermenters - colorless

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what is the pathway of lactose fermentation and what effect does it have on the medium

A

lactose to glucose and galactose
glucose to glycolytic pathway
pyruvate to fermentation
lactic acid created, thus lowering the pH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
does E. Coli create pink or transparent colonies in a macconkey
dark pink
26
how is mannitol salt selective and what about it allows this
inhibits G- allows G+ high NaCl concentration
27
what organism is mannitol salt used to detect
staphylococcus
28
+ v - on mannitol salt
+: mannitol fermenters yellow | -: not mannitol fermenter, pink
29
staphylococcus aureus is manitol ...
positive
30
staphylococcus epidermidis is manitol...
negative
31
reasons to measure presence, growth, and identifications of microorganisms
1. evaluate contamination of food, water, etc 2. ensure microbes are innoculated during processing of beer, wine, yogurt, cheese, etc. 3. evaluate antimicrobial agent efficiency 4. study microbe populations from different ecosystems 5. measure effects of mutations of genes
32
what type of medium is required for viable counts
permissive growth medium
33
in what range are there reliable results for viable counts
between 30 and 300 colonies
34
what do you measure during viable counts and why
colony forming units because theoretically each colony is made from 1 bacteria, so the number of colonies measures how many bacteria is present
35
equation for colony forming units
(# of colonies) / ((dilution plated)(volume plated))
36
what needs to be done to get a viable count of bacterial cultures with a high number of cells
serial dilution
37
what plate in the serial dilution do you base your results off of?
the one in the 30-300 range; only reliable one
38
what do you do in a microscopic count
count all cells (dead or alive) per specific volume under a microscope
39
how do you tell the difference between dead and living cells in a microscopic count
viability stain green = alive red = dead
40
pros of microscopic counts
fast cheap motility can be prevented by increasing viscosity good when you need to count only 1 sample
41
cons of microscopic counts
difficult to see small cells (bacteria) not good when you need to count more than 1 sample harder to count motile cells
42
concept of volume in microscopic counts
height/distance of coverslip from sample, width and length of gridlines allows you to calculate volume. count the number of cells within this volume
43
what is flow cytometry
automated cell counter; puts cells in a straight line and uses a laser to detect flourescent dyes, count, and LABEL cells
44
what information does flow cytometry provide
texture, size, shape, labeling of cells
45
is flow cytometry better at counting small or big cells
big
46
does flow cytometry count cells that alive, dead, or both
it differentiates between dead and alive cells
47
what is the turbidimetric method
measures the contribution of alive and dead cells to turbidity. a spectrophotometer is used to measure how much light the solution blocks
48
what is the relationship between cell density and turbidity
higher density = more opaque/turbid
49
does the turbidimetric measure dead or alive cells>
both
50
what alters the behavior of cells and thus turbidity
clumping and attachment to surfaces
51
what kind of graph can be created with the turbidimetric method
optical density v time
52
what properties affect optical density
size, shape, composition, cell inclusion, etc
53
what does the OD v time curve tell us
the relationship between OD and cell number for different organisms
54
true or false: turbidity accurately detects the number of cells
false; it is an approximation since it tells you dead and alive cells and many properties may affect it
55
what is generation time
time needed for the population to double
56
what does generation time depend on
growth medium and environmental conditions
57
equation for exponential growth of microorganisms and when does this occur
``` N= (N0)(2^n) N = number of cells N0 = initial number of cells n = number of generation this occurs when the conditions are optimal and the population doubles at a constant rate ```
58
equation for generation time
g=t/n g= generation time t = time n = number of generation
59
look at generation time and growth phase graphs and be able to interpret them
okie mims
60
what are the 3 phases of growth that occur in a batch culture
1. lag phase 2. exponential growth phase 3. stationary phase 4. death phase
61
what is happening in the lag phase
the bacteria is placed in the broth and adjusting to its environment. only turbidity line occurs in this region. slow growth
62
what is happening in the exponential growth phase
the viable count starts and both viable count and turbidity exponentially increase - doubling at a constant rate
63
what is happening in the stationary phase
``` limiting nutrients are depleted/accumlation of waste inhibits growth growth stops (plateau) no net increase in cell number cells are metabolically active survival mechanisms activated ```
64
which plataeus first: turbidity or viable count
turbidity
65
what occurs in the death phase
exponential death
66
true or false: batch cultures are continually being affected by the metabolic activities of the growing microorganism
true. ex. depletion of nutrients and generation of toxic waste
67
is the batch culture an open or closed system
closed
68
what about batch cultures is different from the real environment
no turnover of nutrients - most natural environments are open systems
69
what characteristics are present in open systems
1. constant supply of nutrients 2. diffusion of waste 3. competition 4. predation 5. changing environmental conditions
70
how is equilibrium defined for environmental systems
division rate equals death rate
71
what is the main factor for environmental equilibrium
the concentration of a limiting growth factor
72
what is a chemostat used for and how
keep microorganisms in a constant growth rate over a long period of time by providing fresh broth (supply of nutrients) and removing overflow (waste and organisms) at a constant rate
73
what contributes to the death rate of microorganisms in the environment
sickness leading to death, predation (eaten by something else), or being taken away by the environment

Microbio - LSCI 230 (1 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions