BIO - 275 Quiz 3
Glycolysis makes products that feed into ________.
- Krebs cycle - electron transport - fermentation
What two main types of by-products are produced in fermentation?
- acids - alcohol
The presence of microbes in food can be ________.
- beneficia - harmful - neutral
Place the steps in the correct order to review the process of binary fission.
1) a young cell 2) chromosome is replicated 3) protein band forms in center of cell 4) septum formation 5) septum is complete and cells are divided
The generation time of Mycobacterium tuberculosis is _______.
12 hours
What is the total ATP yield per glucose in organisms that carry out fermentation?
2
During one cycle, the sodium-potassium pump binds and moves _______.
3 Na+ and 2 K+
How much ATP is generated in the electron transport system?
34
You ingest 20 cells of Salmonella. This bacterium has a doubling time of 30 minutes. After 4 hours, how many of these bacteria would be present in the body (assuming no immune system responses or other biological activities affect its growth)?
5,120
After six generations, how many bacteria would have formed from the reproduction of one bacterium?
64
How many generations does it take for a single bacterial cell to become 256?
8
If there were 4 viable bacterial cells in an oyster, how many cells would be present after 4 hours if the bacterium exhibited a 20 minute generation time?
8,192
Which of the growth curves represents a facultative anaerobe grown in the presence of oxygen?
A
Which of the growth curves represents an obligate aerobe grown in the presence of oxygen?
A
What is a biofilm?
A group of bacteria that accumulate in layers and secrete an protective extracellular material
Which of the following is the enzyme used to synthesize ATP?
ATP phosphodiesterase ATP hydrolase ATP kinase ATP phosphorylase None of the choices are correct. None of the choices are correct.
What factors can affect the doubling time of a bacterial cell?
All of these factors can affect growth rates.
________ refer(s) only to energy-requiring processes that result in synthesis of cell molecules and structures.
Anabolism
Which of the growth curves represents an aerotolerant anaerobe grown in the presence of oxygen?
B
Consider the biochemical pathway: A - E1 -> B - E2 -> CIf Enzyme 2 is inactive, which of the following compounds will accumulate?
B only
What does the increase in lactate do to blood pH?
Decreases pH
Which of the following is an example of a biofilm commonly found in the human body?
Dental plaque
Which of the following correctly represents the mechanism of enzyme function, where S is "substrate" and E is "enzyme" and P is "product"?
E + S -> E-S -> E-P -> E + P
Where do NADH and FADH2 go after being produced in the Krebs cycle?
Electron transport chain
Which organization monitors commercial food safety in the United States?
FDA
The presence or absence of oxygen has profound effects on the growth of microorganisms based on their ability to tolerate and/or use oxygen in their metabolism. Label the images to demonstrate your understanding of the expected growth patterns in thioglycollate medium based on an organism's oxygen preferences.
Facultative Anaerobe Obligate Anaerobe Microaerophile Obligate Anaerobe Aerotolerant Anaerobe
A hydrogen atom consists of a proton and a pair of electrons.
False
Both human and bacterial cells divide by mitosis.
False
Cells cannot begin a new round of replication until they have completely finished dividing.
False
If you measure turbidity using a spectrophotometer during the death phase, the turbidity will be much lower than it was during the exponential phase.
False
Which of the following signs in the patient would indicate that their body is fighting the microbes causing the UTI?
Fever of 102 degrees Fahrenheit
The physician informs Lisa that cranberry juice appears to reduce the ability of microbes to attach to the urinary tract. Which structures are used for attachment in microbes causing UTIs?
Fimbriae
Which of these represents a proton?
Hydrogen ion
What organ is damaged in Type I diabetes?
Pancreas
What type of relationship is depicted in this image?
Parasitism
Which of the following is NOT a catabolic process?
Photosynthesis
Based upon the data collected, which juice do you hypothesize contains the greatest amount of tannins?
Pomegranate
What type of bacteria will grow in the refrigerator, and why is this usually not a concern?
Psychrophiles; very few are pathogenic to humans
Based on this case, what practice would have helped to prevent the contamination of oysters?
Put the oysters into deeper colder waters.
The two 3-carbon molecules that glucose is split into during glycolysis are converted through a series of steps ending in what 3-carbon molecule?
Pyruvate
What serves as an electron acceptor in fermentation?
Pyruvate or other organic molecule
Which enzyme is NOT involved in DNA replication?
RNA polymerase
Where do the electrons for the electron transport system come from?
Reduced coenzymes
What is the main purpose for fermentation reactions?
Regenerate NAD molecules for glycolysis
Why did the child's breath have a fruity odor?
She was burning fats instead of glucose for fuel
Which of the following will pass through a cell membrane most easily?
Small nonpolar molecules
Looking at the data in this table, this bacterial population is likely in what growth phase between 20 and 24 hours?
Stationary phase
Which of the following binds to the active site of an enzyme?
Substrate
The rate of diffusion is affected by which of the following?
Temperature, size of molecules, and steepness of the concentration gradient
Why was hyperbaric oxygen therapy an effective treatment in this case?
The causative agent is an anaerobe
Why were antibiotics prescribed for Mr. Jones?
The causative agent was a bacterium
How is anaerobic respiration different from aerobic respiration?
The final electron acceptor
Why did the patient's lactate levels rise?
The lactate levels increased due to anaerobic metabolic reactions
Why was it unusual that the oysters from Prince William Sound were contaminated with this bacterium?
The temperature of the Sound is normally too low.
When you inoculate a fresh tube of broth medium, it doesn't instantly turn cloudy. Why is this?
There is lag phase before growth occurs at a level that is visible in the broth.
Which of the following statement(s) about biochemical pathways is(are) TRUE?
They are very well organized and structured and they convert an initial substrate via a series of steps into an end product
For one turn of the Krebs cycle, how many NADH are produced?
Three
Why was the patient treated with IV fluids and oxygen?
To increase oxygen concentration and delivery to tissues
Environmental factors control microbial growth through their influence on enzyme activity.
True
If the doubling time of a bacterium is short, the x-axis of a population growth curve will have smaller numbers.
True
NADH serves as an electron carrier that can donate its hydrogen to other molecules.
True
Protons received from NADH ________.
are pumped outside the cell
Type I diabetes can be considered a(n) ________ disease.
autoimmune
Sepsis is treated with antibiotics to control the ______ that are multiplying in the bloodstream.
bacteria
Most bacteria increase their numbers by _______.
binary fission
Most bacteria reproduce by ________.
binary fission
Most cultured bacteria tend to multiply by ________.
binary fission
Early in glycolysis, two phosphates are added to the glucose molecule. These phosphates come from ________.
breaking down ATP
The NADH involved in the electron transport chain is made ________.
by oxidation reactions in glycolysis and the Krebs cycle
The electron transport system in bacteria is located on the _______ and in eukaryotic cells on the _______.
cytoplasmic membrane; mitochondrion
All biochemical pathways have the same number of enzymatic reactions.
false
An enzyme can only bind one reactant at a time.
false
An enzyme speeds up a chemical reaction in the cell, but can only be used once.
false
Cell division is triggered exclusively when cells attain a threshold mass.
false
DNA helicase is responsible for adding nucleotides to the growing end of the DNA
false
During the stationary phase, binary fission stops.
false
Escherichia and Salmonella are cocci that divide by binary fission.
false
In prokaryotes and eukaryotes, the Krebs cycle takes place in the mitochondria.
false
Only yeast are able to carry out fermentation for catabolism.
false
The Krebs cycle is part of fermentation, as well as cellular respiration.
false
The membrane is permeable to protons.
false
The molecules in a solid lump of sugar do not move.
false
True or False: Females consuming cranberry juice exhibited the greatest incidence of UTIs as compared to the group with no treatment.
false
True or False: The incidence of Type II diabetes is greater than Type I diabetes, regardless of ethnicity.
false
The type of microbial metabolic pathway that is most often exploited to make acids and alcohols industrially is ________.
fermentation
Most bacteria reproduce by _______.
fission
The two 3-carbon molecules which glucose is split into are converted through a series of steps into the final 3-carbon molecule. During these later steps, ________ molecule(s) of ATP are made.
four
The final acceptor for electrons and hydrogens in aerobic respiration is ________.
free oxygen
Clostridium perfringens is the causative agent of ________.
gas gangrene
Glycolysis is the breakdown of ________.
glucose
During glycolysis, _______ is oxidized and _______ is reduced.
glucose; NAD+
The Krebs cycle occurs after ________.
glycolysis
Individual bacteria (such as Salmonella) ________.
grow best at an optimum temperature and a range above and below it
A cell exposed to a hypertonic environment will ______ by osmosis.
lose water
Because this bacterium requires a temperature above 16.5 degrees Celsius, it would be classified as a _______.
mesophile
Most of the microbiota in the human body are classified as ______.
mesophiles
Simple diffusion is defined as the movement of _______.
molecules from areas of higher concentration to areas of lower concentration
Glycolysis starts with _______ and ends with _______.
one glucose; two pyruvate molecules
Hydrogen consists of ________.
one proton and one electron
Consider the biochemical pathway: A - E1 -> B - E2 -> CEnzyme 1 can utilize ________.
only A as substrate
Enzymes that can be shut down or activated based on the presence of chemicals in their environment are called ________.
regulated
The process of decarboxylation involves ________.
removing carbon
Cells must ________ their DNA prior to cell division.
replicate
The FtsZ protein is needed to form the ________.
septum
In the United States, the CDC estimates that ________ people suffer each year from some form of foodborne infection.
several million
Pathogens usually have _____ doubling times.
short
A red blood cell placed in a hypertonic medium will _______.
shrink
During the electron transport chain in bacteria, protons are ________.
shuttled to the outside of the cell membrane
The energy source for contraction of the FtsZ ring during cell division comes from ________.
the hydrolysis of GTP
The safe temperature ranges for the storage of foods are determined by _______.
the low temperature where microbes stop multiplying and the high temperature where they physically die
Oxygen acts as ________.
the terminal electron acceptor
Cells prefer to use carbohydrates as energy sources because ________.
they are such good donors of hydrogen and electrons
The type of food-borne infection known as an intoxication is caused by ________.
toxins produced by microbes as they grow in the food
Coenzyme Q ________.
transfers protons from inside the membrane to outside the membrane
A 5% urea solution is hypotonic to a 10% urea solution.
true
Diffusion is one of the processes whereby materials are exchanged between a cell and its environment.
true
If a cell is placed in an isotonic medium, there will be no net movement of water.
true
In a biochemical pathway, the product of the first reaction becomes the substrate in the second reaction.
true
Rod-shaped bacteria synthesize new cell walls over the entire surface of the cell.
true
The binding and release of sodium or potassium ions are due to conformational changes in the protein.
true
The energy captured in the phosphorylation of ADP to ATP comes from the proton motive force created in respiration.
true
The protons are generated during oxidation reactions.
true
The sodium-potassium pump is a trans-membrane protein.
true
True or False: In kids under the age of 19, there are some ethnic groups that have a greater percentage of Type II diabetes than Type I diabetes.
true
Whenever a molecule is oxidized, another molecule must be reduced.
true
The NET production of ATP upon the completion of the series of glycolytic reactions is ________ molecule(s) of ATP
two
The last carrier protein in the electron transport chain transfers ________.
two electrons to oxygen
During binary fission, one bacterial cell becomes _______ cells.
two genetically identical
Looking at the composite data across all ethnic groups, which type of diabetes is most common in youth under the age of 19?
type I
Many coenzymes are formed from ______.
vitamins
Osmosis is best defined as the movement of _______.
water molecules across a membrane from an area of high water concentration to an area of lower concentration
What is the effect of cold on a population of bacteria?
Cells survive but do not divide at temperatures below the minimum.
What food product is least likely to contain viable vegetative pathogens?
Chicken cooked to 170 degrees F
What food product is least likely to contain viable vegetative pathogens?
Chicken cooked to 170°F
The energy released during the reactions of glycolysis is used to form ________.
adenosine triphosphate
Bacteria that grow in oxygenated environments are referred to as ________.
aerobes
The electron transport chain is part of ________.
aerobic respiration
Most bacteria associated with UTIs make the urine more _______, creating an environment favorable for their growth
alkaline
Bacteria that thrive in environments with a pH of greater than 7 are classified as ________.
alkalinophiles
C. perfringens causes tissue damage by release of ________.
alpha toxin
In eukaryotes, glycolysis takes place in the ________.
cytoplasm
During the electron transport chain, ATP will be made from ________.
ADP + Pi
Why are biofilms important in infectious disease?
Bacteria in biofilms are often protected from antibiotics.
In the case, the patient is treated with antibiotics for her UTIs. Which type of organism must the physician suspect is causing her infections?
Bacterium
What is the source of energy used to power the sodium-potassium pump?
Breakdown of ATP
Which of the growth curves represents an obligate anaerobe grown in the presence of oxygen?
C
What is a by-product of the Krebs cycle?
Carbon dixoide
What is the effect of heat on a population of bacteria?
Cells begin to die at a temperature slightly above the maximum.
Conduct some additional research on gas gangrene, and then move the statements to their proper category to assess your understanding of clinical findings associated with this infection.
Clinical findings not associated with clostridial gas gangrene: - gram staining of cultures reveals gram-negative cocci - endotoxin from organism cause direct muscle tissue damage - optimal culture growth occurs under aerobic conditions Clinical findings associated with clostridial gas gangrene: - optimal culture growth occurs under anaerobic conditions - gram staining of cultures reveals gram-positive bacilli - staining of cultures reveals the presence of bacterial endospores - debridement usually required in combination with antibiotics - gas produced in affected soft tissue
Which of the following contain a metal ion which can accept and donate electrons?
Cytochromes
Where does the Krebs cycle take place in bacteria?
Cytoplasm
What is the usual route for infection with Vibrio parahaemolyticus?
Ingestion of raw or undercooked shellfish
What does it mean to say that C. perfringens can be found as normal biota in the intestine?
It can live in a commensal/mutualistic relationship with the human host
Where does carbon dioxide go when it is released during reactions of the Krebs cycle?
It diffuses out of the cell
Which of the following statements describes Clostridium perfringens?
It is a gram-positive organism
Which of the following is true of passive transport?
It requires a gradient
Which of the following best describes the reduction of the coenzyme NAD+?
NAD+ + H -> NADH
The two 3-carbon molecules which glucose is split into are converted through a series of steps into pyruvate. During these steps _______.
NAD+ is converted to NADH
Hydrogens are transported from other reactions to the electron transport chain by ________.
NADH and FADH
What is oxidized at the beginning of the electron transport system?
NADH and FADH2
What ethnic group is experiencing the most dramatic changes in Type II diabetes, and what is the trend?
Native American; increasing
You leave your potato salad out on the table at the company picnic. When you made it, you unknowingly introduced 100 cells of Salmonella. How much time will it take for the population of Salmonella to reach at least one million if its doubling time is 20 minutes at picnic conditions?
Over 4 hours
What is reduced at the end of the electron transport system?
Oxygen
For each glucose molecule that enters glycolysis, how many times does the Krebs cycle turn?
Two
How many net ATP molecules are produced for each glucose molecule that enters glycolysis?
Two
What is the likely explanation for the contamination of the oysters in this case?
Warmer waters allowed the bacteria to expand their natural habitat.
The energy for the synthesis of ATP in the electron transport chain is provided by _______.
a proton gradient
When protons are pumped outside the cell membrane, ________.
a proton motive force is created
The electron carrier proteins in the electron transport chain shuttle electrons to ________.
a terminal acceptor
The physician suggests that Lisa consume cranberry juice to prevent her recurrent UTIs, due to the fact that the juice makes the urinary tract more ______.
acidic
Proton pumps are an example of _______ transport.
active
If conditions are favorable, the generation time of bacteria _______.
can be as short as 30 minutes
The breakdown of glucose is an example of ________.
catabolism
Synthesis of ATP via a proton gradient is called ________.
chemiosmosis
In a viable count, each _______ represents a _______ from the sample population.
colony; CFU
In this study, the group that did not receive treatment is called the ______ group; this data is necessary to compare results of the various treatments reliably.
control
The structure that divides the bacterial cell in two is termed the ________.
cross septum
Energy is carried from catabolic to anabolic reactions in the form of _______.
high-energy ATP bonds
In bacteria, the electron transport chain is located ________.
in the plasma membrane
Refrigeration will _____ the doubling time of most pathogens.
increase
The patient was deficient in ________.
insulin
After glycolysis, pyruvate can be converted into ________ under anaerobic conditions.
lactic acid
The energy released during the reactions of glycolysis is released by ________ reactions
oxidation
Cells obtain energy by ________ food molecules such as glucose.
oxidizing
A pathogen would most accurately be described as a ______.
parasite
An organism that can synthesize all its required organic components from CO2 using energy from the sun is a _______.
photoautotroph
This patient's wound was likely caused by ________.
poor circulation from diabetes
The main purpose of cellular respiration is to ________.
produce energy
Enzymes are ________.
proteins
In this reaction, ATP synthase uses energy from ______ to make ATP.
protons reentering the cell
Proton pumps are protein complexes that ________.
pump protons from the interior of the cell to the exterior
The sodium-potassium pump functions to pump _______.
sodium ions out of the cell and potassium ions into the cell
The environmental factor that influences bacterial growth the most is _______.
temperature
When sugar is mixed with water, equilibrium is reached when _______.
the dissolved sugar molecules are evenly distributed throughout the solution