WorksheetsBMOL6401 - L5 - Microbial Environment Requirements
Total questions: 65
Worksheet time: 55mins
Name
Class
Date
1.
What does physiochemical parameters mean?
a)
Factors affecting the environment
b)
Physical and chemical factors
c)
Only temperature and pH
d)
Only chemical properties
e)
Water availability
2.
What is a psychrophile?
a)
Cold-loving organism
b)
Heat-resistant organism
c)
Salt-resistant organism
d)
High-pressure organism
e)
Acid-resistant organism
3.
What is a thermophile?
a)
Cold-loving organism
b)
Heat-loving organism
c)
Salt-loving organism
d)
Acid-loving organism
e)
Pressure-loving organism
4.
What is a halophile?
a)
Cold-loving organism
b)
Heat-loving organism
c)
Salt-loving organism
d)
Acid-loving organism
e)
Pressure-loving organism
5.
Which of these is a non-negotiable need for life?
a)
Oxygen
b)
Nitrogen
c)
Salt
d)
Water
e)
Carbon dioxide
6.
Define extremophiles
a)
Organisms that thrive in moderate conditions
b)
Organisms that thrive in extreme conditions
c)
Organisms that die in extreme conditions
d)
Organisms with a short lifespan
e)
Organisms with high adaptability
7.
As temperature increases, gas solubility…
a)
Increases
b)
Decreases
c)
Stays the same
d)
Fluctuates
e)
None of the above
8.
How can you prevent ice crystals forming in cells at low temperatures?
a)
Add salt
b)
Add glycerol
c)
Increase pressure
d)
Add antifreeze chemicals
e)
Heat the cells
9.
Define cardinal temperatures
a)
Temperatures where no growth occurs
b)
The temperature at which the organism grows best
c)
The maximum temperature organisms can tolerate
d)
The minimum, optimum, and maximum temperatures organisms grow
e)
The minimum temperature only
10.
Define psychrophiles
a)
Cold-loving organisms
b)
Heat-loving organisms
c)
Salt-loving organisms
d)
Acid-loving organisms
e)
Pressure-loving organisms
11.
Define mesophile
a)
Cold-loving organisms
b)
Moderate-temperature-loving organisms
c)
Heat-loving organisms
d)
Salt-loving organisms
e)
Pressure-loving organisms
12.
Define thermophile
a)
Cold-loving organisms
b)
Heat-loving organisms
c)
Salt-loving organisms
d)
Acid-loving organisms
e)
Pressure-loving organisms
13.
Define hyperthermophile
a)
Organisms that grow at very high temperatures
b)
Organisms that grow at very low temperatures
c)
Organisms that grow in acidic environments
d)
Organisms that grow at moderate temperatures
e)
Organisms that live in extreme cold
14.
Most pathogens are…
a)
Psychrophiles
b)
Mesophiles
c)
Thermophiles
d)
Hyperthermophiles
e)
Halophiles
15.
What are some molecular adaptations of psychrophiles to function optimally in the cold?
a)
Increase β-sheets
b)
Decrease polar residues
c)
Increase prolines
d)
Increase hydrophobic residues
e)
Increase H-bond-forming residues
16.
Increase in glycines is typical molecular adaptations of…
a)
Psychrophiles to function in cold
b)
Thermophiles to function in heat
c)
Halophiles to function in salt
d)
Acidophiles to function in acid
e)
Hyperthermophiles
17.
Decrease in prolines is a molecular adaptation seen in…
a)
Thermophiles
b)
Psychrophiles
c)
Halophiles
d)
Acidophiles
e)
Hyperthermophiles
18.
Decreasing residues that form H-bonds allows organisms to function in…
a)
Cold (psychrophiles)
b)
Heat (thermophiles)
c)
Salt (halophiles)
d)
Acid (acidophiles)
e)
High-pressure (barophiles)
19.
What are cold shock proteins and cryoprotectants?
a)
Heat-shock proteins and water
b)
Cold-shock proteins and antifreeze proteins
c)
Ice-forming proteins and salt
d)
Heat-shock proteins and glycerol
e)
Proteins used for freezing cells
20.
To allow their transport processes to function optimally at low temperatures, psychrophiles…
a)
Increase prolines
b)
Increase hydrophobic residues
c)
Modify their cytoplasmic membranes
d)
Increase β-sheets
e)
Produce more enzymes
21.
Psychrophiles aim to make themselves...
a)
Less rigid, more flexible
b)
More rigid, less flexible
c)
Smaller in size
d)
Larger in size
22.
Psychrophiles want to limit...
a)
Nutrient uptake
b)
Energy production
c)
Interactions between molecules
d)
Water absorption
23.
Membrane composition of psychrophiles are...
a)
Lipid membrane is saturated
b)
Lipid membrane is unsaturated
c)
Lipid membrane has high cholesterol
d)
Lipid membrane has low cholesterol
24.
Membrane composition of thermophiles are...
a)
Lipid membrane is saturated
b)
Lipid membrane is unsaturated
c)
Lipid membrane has high cholesterol
d)
Lipid membrane has low cholesterol
25.
Define psychrotolerant microorganisms
a)
Organisms that grow optimally at low temperatures but can tolerate high temperatures
b)
Organisms that tolerate cold temperatures but grow optimally at moderate temperatures
c)
Organisms that only grow in cold environments
d)
Organisms that grow in hot environments
26.
If an organism doesn’t grow, it means it will die
a)
True
b)
False
27.
Halophiles grow best at...
a)
Low salt concentrations
b)
Moderate salt concentrations
c)
High salt concentrations
d)
No salt concentration
28.
Antarctic microbes are most likely to be equipped with which molecular adaptation?
a)
Proteins with more β-sheets
b)
Proteins with more α-helices
c)
Proteins with high thermal stability
d)
Proteins with high salt tolerance
29.
Above 65 degrees, usually only _____ can exist
a)
Eukaryotes
b)
Prokaryotes
c)
Archaea
d)
Viruses
30.
Thermophiles optimum growth temperature is...
a)
45-55 degrees
b)
55-65 degrees
c)
65-75 degrees
d)
75-85 degrees
31.
Hyperthermophiles optimum growth temperature is...
a)
Above 55 degrees
b)
Above 65 degrees
c)
Above 80 degrees
d)
Above 100 degrees
32.
What is the difference between eukaryotes and prokaryotes?
a)
Eukaryotes have a nucleus, prokaryotes do not
b)
Prokaryotes have a nucleus, eukaryotes do not
c)
Eukaryotes are single-celled, prokaryotes are multi-celled
d)
Prokaryotes are larger in size
33.
What is Thermus aquaticus used for?
a)
Gene cloning
b)
PCR (polymerase chain reaction)
c)
Protein synthesis
d)
Metabolic engineering
34.
What do the molecular adaptations for thermophiles aim to achieve?
a)
Stability at lower temperatures
b)
Flexibility at higher temperatures
c)
Stability at higher temperatures
d)
Flexibility at lower temperatures
35.
Increase in H-bonds and non-covalent interactions...
a)
Increase membrane permeability
b)
Make molecules less rigid
c)
Weaken protein structures
d)
Strengthen structures at higher temperatures
36.
Thermophiles molecular adaptations include...
a)
High glycine content for flexibility
b)
High proline content for stability
c)
High polar residue content
d)
Low proline content for flexibility
37.
How is DNA stabilized in thermophiles?
a)
Histone-like proteins
b)
Chaperone proteins
c)
HSPs
d)
Beta-sheets
38.
In thermophiles...
a)
Chaperone proteins help protein unfolding
b)
Chaperone proteins help protein folding
c)
Proteins require less assistance to fold
d)
Proteins do not fold
39.
In thermophiles, there are more alpha-helices than beta-sheets to increase stability.
a)
True
b)
False
40.
What is the role of chaperones?
a)
Assist protein unfolding
b)
Assist correct protein folding
c)
Prevent protein degradation
d)
Inhibit protein synthesis
41.
What are HSPs and what do they do?
a)
Refold denatured proteins after heat shock
b)
Assist protein synthesis
c)
Prevent protein degradation
d)
Assist protein folding
42.
What are thermosomes?
a)
Specialized lipids for heat tolerance
b)
Heat-tolerant RNA molecules
c)
Special class of chaperonins
d)
High-temperature enzymes
43.
How is the membrane of bacteria adapted to thermophily?
a)
Low proportion of saturated fatty acids
b)
High proportion of unsaturated fatty acids
c)
High proportion of saturated fatty acids
d)
Low hydrophobic interactions
44.
How is the membrane of archaea adapted to thermophily?
a)
Lipids contain fatty acids
b)
Lipids contain isoprene repeats
c)
Lipids contain ester linkages
d)
Lipids contain unsaturated fatty acids
45.
Organisms that grow best between pH 6 and 8 are called...
a)
Neutrophiles
b)
Acidophiles
c)
Alkaliphiles
d)
Halophiles
46.
Acidophiles grow best at a pH of...
a)
< 4
b)
< 5
c)
< 6
d)
< 7
47.
Some alkaliphiles grow at pH >9 and have adapted by having a...
a)
Sodium-potassium pump
b)
Calcium pump
c)
Proton pump
d)
Acid tolerance system
48.
What is an example of acid tolerance response?
a)
Decrease in internal pH
b)
Synthesize heat-shock proteins
c)
Pump protons into the cell
d)
Pump protons out of the cell
49.
Producing acidic or basic waste products helps the organism...
a)
Neutralize toxins
b)
Change the pH of their habitat
c)
Store energy
d)
Decrease temperature
50.
What does osmolarity mean?
a)
Concentration of protons
b)
Concentration of water molecules
c)
Concentration of solutes
d)
Concentration of gases
51.
Define Xerophiles
a)
Organisms that grow in dry environments
b)
Organisms that grow in high sugar
c)
Organisms that grow in salt water
d)
Organisms that grow in high pressure
52.
Define Halophiles
a)
Organisms that grow in dry environments
b)
Organisms that grow in high salt
c)
Organisms that grow in high sugar
d)
Organisms that grow in high pressure
53.
Define Osmophiles
a)
Organisms that grow in high salt
b)
Organisms that grow in high sugar
c)
Organisms that grow in low oxygen
d)
Organisms that grow in acidic environments
54.
Define Halotolerant organisms.
a)
Organisms that can tolerate low salt but grow best without it
b)
Organisms that grow best in high salt
c)
Organisms that grow in low sugar
d)
Organisms that grow in dry environments
55.
Define isotonic solution.
a)
A solution with a lower solute concentration than the cell
b)
A solution with equal solute concentration as the cell
c)
A solution with a higher solute concentration than the cell
d)
A solution that has no solutes
56.
Define hypertonic solution.
a)
A solution with a lower solute concentration than the cell
b)
A solution with equal solute concentration as the cell
c)
A solution with a higher solute concentration than the cell
d)
A solution with no solutes
57.
Typically, the cytoplasm has a ______ solute concentration than the surrounding environment, therefore water has a tendency to move _______ the cell.
a)
Higher, out of
b)
Higher, into
c)
Lower, out of
d)
Lower, into
58.
How do cells cope with low water activity?
a)
By pumping out inorganic ions
b)
By decreasing cytoplasmic membrane permeability
c)
By synthesizing organic solutes or pumping in inorganic ions
d)
By decreasing cellular metabolism
59.
What are compatible solutes (CS) and how are they used to help cells cope with low water activity?
a)
They are inorganic solutes used to regulate pH
b)
They are organic osmolytes compatible with cell metabolism
c)
They are ions used to increase cellular respiration
d)
They are proteins used to maintain cell integrity
60.
What are ROS?
a)
Reactive oxygen species
b)
Ribosomal organic sequences
c)
Rigid organic structures
d)
Radioactive oxygen solutes
61.
What does barotolerant mean?
a)
An organism that grows only under high pressure
b)
An organism unaffected by pressure
c)
An organism that grows only in low pressure
d)
An organism that thrives in hypertonic conditions
62.
What are some molecular adaptations to increased pressure?
a)
Decreased membrane fluidity
b)
Higher proportion of unsaturated fatty acids in membranes
c)
Increased H-bonding in the cell membrane
d)
Higher proportion of saturated fatty acids in membranes
63.
What is special about Deinococcus radiodurans?
a)
It is the smallest bacterium known
b)
It can survive extreme heat
c)
It is extremely resistant to ionizing radiation
d)
It can survive without oxygen
64.
How many Rads are lethal to humans?
a)
10 rad
b)
50 rad
c)
100 rad
d)
150 rad
65.
Endospores have a water content of ______.
a)
10-25%
b)
50-60%
c)
70-80%
d)
5-10%
100 %
