quizzes from unit 2 Flashcards
One cell with generation times of 60 minutes are inoculated into a culture medium. How many cells are there after 5 hours?
32
2 bacterial cells with generation time of 20 minutes are inoculated into a culture medium. How many cells are there after 2 hours? (Assuming all cells divide by binary fission in log phase and remained viable).
128
A virus such as influenza virus might produce 800 progeny virus particles from one host cell infected by one virus.
How would you mathematically represent the exponential growth of the virus?
800^n
A cafeteria worker who fails to wash his hands thoroughly and fails to wear gloves inoculates a pie with 4 E.coli cells in when he uses his finger to test whether it is done.
By the time you purchase the pie, there were 128 E.coli cells. How many generations did the cells go through between the initial inoculation and the time you bought the pie? Assuming all cells multiplied in a log phase.
5
A cafeteria worker who fails to wash his hands thoroughly and fails to wear gloves inoculates a pie with 4 E.coli cells in when he uses his finger to test whether it is done.
By the time you purchase the pie, there were 128 E.coli cells. How many minutes it took from the time he touched it until you purchased it? Assuming all cells multiplied in a log phase.
FYI, E. coli have a generation time of 20 minutes.
100
You have obtained a pond water sample and wish to determine the concentration of bacteria. After making two 1/100 dilutions, you plate 1 ml of the second dilution onto agar plate. After appropriate incubation, you found 155 colonies. What was the concentration of bacteria (CFUs) per ml of the pond water sample?
1.55 x 10^6
You inoculated 25 bacteria A, with a generation time of 20 minutes, into 200 ml of nutrient broth. At the same time, you inoculated 75 bacteria B with generation time of 20 minutes into 100 ml of nutrient broth. After incubation for 24 hours, if all cells divide by binary fission and remain viable in log phase, you can reasonably expect to have
(a) the same number of cells in both cultures
(b) more Bacteria A in the 100ml.
(c) more Bacteria B in the 100ml.
(d) The answer cannot be determined based on the information provided.
(c) more Bacteria B in the 100ml.
You inoculated 25 bacteria A, with a generation time of 10 minutes, into 100 ml of nutrient broth. At the same time, you inoculated 75 bacteria B with generation time of 20 minutes into 200 ml of nutrient broth. After incubation for 24 hours, if all cells divide by binary fission and remain viable in log phase, you can reasonably expect to have
(a) more Bacteria B in the 200ml.
(b) The answer cannot be determined based on the information provided.
(c) more Bacteria A in the 100ml.
(d) the same number of cells in both cultures
(c) more Bacteria A in the 100ml.
C. botulinum is an aerotolerant anaerobic bacterium able to survive in the presence of oxygen with the help of certain metabolic antioxidants.
Which of the following enzymes would you expect to find in C. botulinum that you would not find in a strict anaerobic bacteria?
(a) phosphofructokinase
(b) pyruvate dehydrogenase
(c) hexokinase
(d) superoxide dismutase
(d) superoxide dismutase
Neisseria meningitidis is cultured on chocolate agar, a medium containing red blood cells that help cultivate the fastidious Neisseria bacteriumto detectable levels. What type of growth medium is chocolate agar based on the description?
enriched medium
Which of the following types of media are NOT correctly matched with their description?
(a) Selective media—favor the growth of one organism over another
(b) Synthetic media—nutrient rich but poorly defined
(c) Differential media—exploit differences between two species that grow equally well
(b) Synthetic media—nutrient rich but poorly defined
What is the fastest way to measure cell density?
spectrophotometer(measures optical density)
A student who was trying to determine the concentration of Escherichia coli in a sample completed a total plate count assay. After plating 1mL of the 10-6dilution tube and incubating the plate at 37oC for 24 hours the student counted 210 colonies on the plate. What is the CFU/mL of the original sample?
2.1 x 10^8 cfu/mL
You notice something is growing in a 100ml pot of liquid soap. You took 1ml of this liquid soap and performed a serial dilution and plate to determine the number of bacteria per 1ml in the liquid soap. From the 1:100,000 dilution tube, you plated out 0.1ml and counted of 37 colonies. How many bacteria were present in 1ml of soap (cfu/1ml)?
3.7 x 10^7 cfu/1ml
One cell with generation times of 60 minutes are inoculated into a culture medium. How many cells are there after 5 hours? (Assuming all cells divide by binary fission in log phase and remained viable).
32
Five cells with generation times of 60 minutes are inoculated into a culture medium. How many cells are there after 5 hours? (Assuming all cells divide by binary fission in log phase and remained viable).
160
A cafeteria worker who fails to wash his hands thoroughly and fails to wear gloves inoculates a pie with 4 E. coli cells in log phase when he uses his finger to test whether it is done. By the time you purchase the pie, there are 128 E. coli cells in it. How many generations did the cells go through between the initial inoculation and the time you bought the pie?
5
All of the following statements about ABC transporters are true EXCEPT
Check module 4 to answer this question.
a. They require energy.
b. They can be used for import and export.
c. They are the largest family of transporters.
d. The are found only in prokaryotes.
d. The are found only in prokaryotes.
Which of the following is NOT correct with respect to the redox pair NAD+/NADH?
A) NAD+ can accept electrons during glycolysis and gets reduced to NADH
B) In glycolysis, a total 2 net ATP are produced per each glucose
C) The reduced NADH is at a higher energy than the aromatic ring of NAD+
D) In glycolysis, NAD+ is oxidized to NADH
D) In glycolysis, NAD+ is oxidized to NADH
In Glycolysis, _____ ATP are invested and ______ ATP are created.
2, 4
You feed E. coli 3 glucose molecules. How many net ATP are created by glycolysis.
6
The Entner-Dourdoroff (ED) pathway and the Pentose Phosphate Pathway (PPP) both produce NADH.
True/False
False
What are the overall (NET) products of glycolysis?
2 Pyruvates, 2 ATP, 2 NADH
Which of the following is not an end product of fermentation?
a) Pyruvate
b) Propionate
c) Acetone
d) Carbon Dioxide
a) pyruvate
Fermentation produces more energy than anaerobic Respiration.
True/False
False
Why do bacterial cells need fermentation?
to reduce NAD+ to NADH
The maximum theoretical yield of ATP from aerobic cellular respiration is 38 ATP. On the other hand, mitochondria produce higher proton potential during ETS but the total mitochondrial ATP yield is lower than the ATP produced by E. coli by aerobic respiration.
True/False
True
Rank according to net ATP yield, from high to low.
- Eukaryotic respiration
- E. coli aerobic respiration
- Anaerobic respiration
2, 1, 3
Rank according to net ATP yield, from high to low.
- E. coli fermentation
- E. coli aerobic respiration
- Anaerobic respiration
2, 3, 1
An unknown bacterium can be tested for fermentation of lactose to mixed acid byproducts such as malic acid and succinic acid through which of the following tests?
(a) Phenol red test
(b) Methyl Red test
(c) Voges-Proskauer test
(d) Any of the three tests can be used
(b) Methyl Red test
E. coli ETS includes which of the following components (select more than one answer. You will lose points for selecting wrong answer).
(a) Mobile electron carrier
(b) Terminal electron acceptor
(c) NADH dehydrogenase or oxidoreductase
(d) Ubiquinol:cytochrome c oxidoreductase
a, b, and c
E. coli produces __________ ATP by substrate level phosphorylation and ___________ ATP from oxidative phosphorylation from aerobic respiration of single glucose molecule.
4, 34
Which of the following is NOT true about mitochondrial ETS.
(a) Mitochondrial ETS can produce ATP without the use of ATP synthase
(b) Mitochondrial ETS is capable of producing more proton motive force when compared with E. coli ETS
(c) Possess an intermediate ubiquinol:cytochrome c oxidoreductase complex
(d) Mitochondrial ETS pumps 12 H+ per NADH, 2 more than E. coli
(a) Mitochondrial ETS can produce ATP without the use of ATP synthase
Rank the energy yield, from the highest to lowest, from catabolism of single glucose molecule.
(a) Unable to determine based on presented information
(b) Aerobic respiration - Anaerobic respiration - Fermentation
(c) Anaerobic respiration - Aerobic respiration - Fermentation
(d) Aerobic respiration - Fermentation - Anaerobic respiration
(e) Fermentation - Anaerobic respiration - Aerobic respiration
(b) Aerobic respiration - Anaerobic respiration - Fermentation
Which of the following pathways would be fully operational only in respiring bacteria?
Hint: Select multiple answers. You will be penalized for selecting a wrong choice.
(a) Pentose Phosphate Pathway
(b) ETS
(c) Fermentation
(d) TCA
(e) Glycolysis
(b) ETS and (d) TCA
Which of the following statements about anaerobic respiration is TRUE?
(a) it is also called fermentation
(b) it does not require ETS
(c) it generates only 2 ATP per single glucose
(d) use oxidized ions of nitrogen, and sulfur as their final electron acceptor
(d) use oxidized ions of nitrogen, and sulfur as their final electron acceptor
