Midterm Flashcards
Chapters 4-8 & Lab exam 1
Which of the following is an example of phagocytosis?
A white blood cell engulfing a bacterium
Which type of stain would you use for bacteria that have a capsule?
Negative Staining
What organelle is highly abundant in bacteria?
Ribosomes
Oxygen must be present for pyruvic acid to enter the Kreb cycle.
True
Which of the following are attributes of Gram positive bacteria? Select all that apply.
60-90% of cell wall is peptidoglycan
Stain purple
Complete the equation for the oxidation of glucose. What are the correct coefficients for each molecule?
1; 6; 6; 6
Where does the Krebs cycle occur in prokaryotes?
Cell Wall
What is the function of vacuoles?
store materials such as starch and fat
All bacteria can form capsules.
False
Heat fixation accomplishes 3 things. Select all that apply.
Kills the organism
Causes the organism to adhere to the slide
What are ways to speed up a biological reaction? Select all that apply
Add an enzyme/catalyst
Increase the temperature
What part of the microscope allows precise control of moving the slide?
Mechanical stage
Which of the following are the proper names for parts of a compound light microscope? Select all that apply.
Ocular lens
Mechanical stage
Iris diaphragm
Which form of movement causes vesicles to pinch off from the plasma membrane and enter the cell.
Endocytosis
Which of the following are forms of movement across a membrane? Select all that apply.
Exocytosis
Active transport
Diffusion
Which stain would you want to use to identify mycobacterium?
Acid-fast staining
Aerobes do not use oxygen.
False
Which of the following statements about enzymes are true? Select all that apply
They have a region known as the active site
They exhibit a high degree of specificity
How many times were the first simple microscopes capable of magnifying an object?
100 – 300X
Which of the following are examples of light transmission? Select all that apply.
Seeing a fish swimming in a pond
Peeking through someone’s window
What is used to prevent blurring of a microscope image due to the refraction of light through different media?
Immersion oil
Which type of bacteria don’t form arrangements?
Spiral bacteria
What is the total ATP yield from 1 glucose following glycolysis, Krebs cycle and electron transport?
38
What happens during event 4 of glycolysis?
ATP and pyruvic acid are formed
Which are components of an endospore? Select all that apply.
Spore coat
Core
The most commonly used dyes in microbiology (such as methylene blue or crystal violet) are ___.
positively charged
In aerobic respiration, oxygen becomes reduced to what?
Water
The site of ATP synthesis in prokaryotic cells is the ___. While in eukaryotic cells it is the___.
Cell membrane; mitochondria
How does a cationic dye work?
It is attracted to the negatively charged cell surface
The eukaryotic cell is the basic structural unit for all organisms in the protist, plant, animal and fungi kingdoms.
True
ATP synthase coverts ATP to ADP?
False
This type of microscopy, which makes use of antibody staining is widely used in diagnostic procedures to determine if an antigen is present.
Fluorescent microscopy
Which of the following statements is FALSE regarding prokaryotes?
Prokaryotes include viruses
Put the steps of the electron transport chain/oxidative phosphorylation in order.
1) NADH releases its electrons to the ETS system
2) Electrons move from complex to complex, releasing energy, which is used to pump H+ ions into the intermembrane space
3) Oxygen captures the electron
4) H+ ions diffuse through ATP synthase
5) ATP synthase converts ADP to ATP
What is the name of the molecule formed during Event 1 of glycolysis?
fructose 1,6-diphosphate
What happens during Event 2 of glycolysis?
Fructose is split into two 3-carbon molecules
Oxidative phosphorylation occurs in the nucleus.
False
What is the name of the lowest magnification objective lens (on a standard 4 objective lens microscope)?
Scanning lens
Which molecules are found in glycolysis? Select all that apply.
Pyruvic acid
Glyceraldehyde 3-phosphate
Fructose 1,6-diphosphate
Which of the following can be found in prokaryotic cells? Select all that apply.
Ribosomes
Vacuoles
Which of the following is TRUE about phagocytosis? Select all that apply.
Large vacuoles form around microorganisms or debris
The association of endotoxin in Gram-negative bacteria is a result of the presence of.
Lipopolysaccharide
What is the purpose of a condenser in a compound light microscope?
It converges light beams through a specimen
The term “fluid mosaic” refers to:
the cell membrane
What makes a microscope a compound microscope?
It has more than one lens
During aerobic cellular respiration, most of the energy is produced during:
Electron transport chain
Which of the following organelles is responsible for converting toxic hydrogen peroxide into harmless water and oxygen?
Peroxisome
On a hot day, one wants to avoid wearing black clothes because black reflects all light rays.
False
Match the following terms
- Krebs cycle 2 ATP formed
- Glycolysis, Krebs & ETS 38 ATP formed
- ETS 34 ATP formed
In event 1 of glycolysis, the 2 phosphates from ATP provide the activation energy necessary for glycolysis to proceed.
True
You just completed a gram stain, and upon looking through the microscope, you see that your slide has a unevenly stained cells. What would your bacteria.
Gram-variable
Which of the following are proper names for parts of a compound light microscope? (select all that apply)
Condenser
Arm
Objective lens
The enzyme lysosome is found in tears and digests peptidoglycan
False
What color do cells stain in a negative stan?
Clear
Which of the following are attributes of eukaryotic cells? (select all that apply)
Endoplasmic reticulum
Can have cilia
What is oxidative phosphorylation?
The conversion of ADP to ATP
APT synthesis converts ATP to ADP
False
A typical oil immersion lens on a microscope with a 10X ocular lens provides a total magnification of 1000X
True
Eukaryotic cells contain membrane-enclosed organelles
True
Eukaryotic flagella move like a rotating hook
False
This type of microscopy, which makes use of antibody staining is widely used in diagnostic procedures to determine if an antigen is present
Fluorescent microscopy
A compound microscope can have up to 4 interchangeable lenses that have different powers of magnification.
False
Which of the following are a part of catabolism? (select all that apply)
Energy for movement
Energy for transport
How many ATP are formed in glycolysis (total)
4
Which of the following are TRUE regarding passive transport? (select all that apply)
Particles move with concentration gradient
No energy is expended
Spiral cells are also known as bacillus
False
What is the total magnification of your microscope if the magnifying power of the ocular lens is 5X and your objective lens is 40X
200x
in order to see two objects separately (rather than as one) the wavelength of light must be ___ the distance between the objects
Shorter than
Which of the following statements is FALSE regarding prokaryotes?
Procaryotes include viruses
Which form of movement of substances is most important to microbiologists?
Phagocytosis
Staining a specimen ___ differences in the index of refraction
Increases
Bacteria consist primarily of cytoplasm
True
What part of the cell does glycolysis occur?
Cytosol
Which of the following are examples of light transmission? (select all that apply)
Seeing a fish swimming in a pond
Peeking through someones window
What color will a vegetative cell stain?
Red
Aerobes are capable of using oxygen for energy
True
What happens during event 2 of glycolysis?
Fructose is split into two 3-carbon molecules
Which bacterial shape generally does not have flagella?
Cocci
What is the total magnification of your microscope if the magnifying power of the ocular lens is 5X and your objective lens is 100X
500X
Which of the following statements is FALSE?
The cell wall functions solely to maintain the shape of the cell
The majority of an aerobe’s energy comes from glycolysis
False
What is the name of the lens that is closest to your eyes in a compound light microscope?
Ocular lens
Where does the electron transport chain occur?
mitochondria
Gram negative cells can have as many as 40 layers of peptidoglycan
False (gram + does)
When light strikes an object and bounces back (giving a color) this is known as ___.
Reflection
Bacterial pili are used for
Adherence to surfaces
Which of the following are examples of cofactors? (select all that apply)
Zinc
Magnesium
Manganese
The ___ is the amount of energy required to start a reaction
Activation energy
The association of endotoxin in gram-negative bacteria is a result of the presence of
Lipopolysaccharide
The eukaryotic plasma membrane is identical in structure and function to the prokaryotic cell membrane
False
Which of the following are examples of light reflection? (select all that apply)
A white t-shirt
Black asphalt
A blue colored house
What is the function of the Golgi apparatus?
Package substances into vesicles and releases them
Which of the following are true about phosphorylation? (select all that apply)
Addition of a phosphate group to a molecule
Happens early in glycolysis
What happens during event 3 of glycolysis?
NAD is oxidized and reduced, and electrons are transferred to it for later use in the ETS
Total magnification of a microscope is the object lens power divided by the ocular lens power
False
Bacterial media that are composed of ingredients whose exact chemical composition are known are called
defined
What are the nutrients that microorganisms use as building blocks to synthesize cell components and synthesize enzymes?
Nitrogen
Carbon
Actively metabolizing bacterial cells can live with or without water in their environment.
false
Acidophiles like basic pHs.
false
Given the following DNA template sequence, what is the complementary messenger RNA sequence? 3’-ATGCCCTAG-5’
5’-UACGGGAUC-3’
Which of the following are TRUE regarding the log phase of growth? (Select all that apply)
population growth is exponential
Which of the following is NOT true about the lag phase of growth. (select all that apply)
organisms increase significantly in number
What type of media contains reasonable familiar materials but varies slightly in composition from batch to batch?
synthetic
When a spore returns to its vegetative state. What happens during outgrowth?
proteins, RNA, and DNA are synthesized
In eukaryotes, what is the name of the noncoding region in DNA segments?
interons
What type of replication is DNA replication, where each daughter strand contains one parent strand?
semiconservative
What type of bond holds adjacent amino acids together in a growing polypeptide chain?
peptide bonds
Which of the following statements is true?
pH 6 is more basic than pH 3
There are no bacteria capable of tolerating the full pH range.
true
Exactly 100 bacteria with a generation time of 60 minutes are introduced into fresh broth at 9:00am and maintained at an optimum incubation temperature throughout the day. How many bacteria are present by 5:00pm?
8 generations
I have a pH of an 8 and a pH of a 13. How much more acidic is the 13? (Choose the correct answer)
it is more basic
Which of the following are characteristics of transfer RNA? (Select all that apply)
This RNA carries amino acids to growing protein
This RNA contains a 3-base anticodon
What color does methylene blue turn in the absence of oxygen?
colorless
Select all answers that are physical factors.
Temperature
pH
radiation
Measuring metabolic products of a cell population is a method for directly measuring number of bacteria present.
false
Each tRNA has a three-base ___ that is complementary to a particular mRNA codon.
anticodon
During DNA replication, the lagging strand runs in the 3’ to 5’ direction.
true
What is the pH range for an alkaliphile?
7.0 - 11.5
Give the correct order for the following phases of growth (number them 1-4 from first to last phase):
1) Lag phase
2) Log phase
3) Stationary phase
4) Decline phase
What base replaces thymine in RNA?
uracil
What 3 signals can induce a bacterium to form an endospore? (select 3 answers)
Metabolic
Environmental
Cell cycle
In a colony, all cells are perpetually in the same growth phase.
false
Ribosomes, mRNA and tRNA are reusable.
true
Peptone media is often enriched with soybean extract.
false
A codon is made up of how many bases?
3
Halophiles are not capable of surviving in environments with greater than 10% salt concentrations.
false
When moved to a lower pressure environment, proteins and enzymes in a barophile denature, killing it.
true
If you counted 52 colonies on a plate and had a dilution factor of 10⁴, what is the count in CFU/ml?
5.2 x 10⁵
What are the ways in which information is transferred in a cell? (select all that apply)
Replication
Transcription
Translation
A mother cell must ___ in size and duplicate in size before dividing into daughter cells.
double
What is the name for short DNA segments used to synthesize the new DNA on the lagging strand?
okazaki fragments
Match each of the following terms with their correct definition
Facultative anaerobe – uses aerobic metabolism when oxygen is available but can undergo fermentation when there is no oxygen
Obligate anaerobe – killed by oxygen
Obligate aerobe – requires oxygen to grow
Which of the following pairs are not complementary?
A-G
When doing an MPN test, what 3 volumes of a dilution are used? (select 3 answers)
0.1 ml
1 ml
10 ml
In protein synthesis, what type of RNA serves as the template for amino acid sequence?
mRNA
Most lab cultures will use media containing peptone.
true
Human blood is the blood of choice for enriching agar medium when studying hemolysis.
false
Match the term with the correct pH. (match the following)
Neutral 7
Extremely basic 14
Extremely acidic 0
Growth of most bacteria 6-9
Most microbes cant grow in a pH more than 1 pH unit above/below their optimum pH.
true
Match the following terms to their correct definition:
Lag phase organisms are metabolically active but not increasing in number
Decline phase cells lose ability to divide and die
Log phase exponential cell population growth
Stationary phase number of new cells produced equal number that are dying
Mark all answers that are considered acidic. (mark all that apply)
Wine
Urine
Which phase of cell growth represents when cell death exceeds cell growth?
decline phase
What enzyme is responsible for unwinding two strands of DNA?
helicase
For each of the following state whether it is associated with replication, transcription or translation
Origin replication
P site translation
DNA converted to RNA transcription
Anticodon
translation
What is hydrostatic pressure?
The pressure exerted by standing water in proportion to its depth
What is the pH range for a neutrophile?
5.4 - 8.0
What is the name of the microbe capable of withstanding extremely high pressure?
barophile
A bacterial colony is formed when a single cell divides exponentially.
true
You’re currently on vacation visiting some local caves. What type of bacteria will you most likely find there?
acidophiles
Which are the three pH classifications for bacteria? (Select 3 answers)
Alkaliphiles
Neutrophiles
Acidophiles
You are getting ready for a dip in a natural hot spring. What type of bacteria will you most likely find there?
thermophiles
what are some of the trace elements needed by microorganisms? (Select all that apply)
zinc
iron
in prokaryotes, chromosomes are ___, while in eukaryotes they are ___.
circular; linear
Which of the following statements about endospores is true? (Select all that apply)
Endospore formation generally occurs because of environmental stressors such as limited nutrients
Endospore formation occurs in certain gram positive bacteria
The matching of a codon to an anticodon is what specifies the sequence of amino acids in a protein.
true
How many chromosomes are found in a typical bacterial cell?
1
Given the following original DNA strand, select the sequence of the strand synthesized during replication: CATTGGCCA
GTAACCGGT
DNA polymerase adds nucleotides to the 5’ end of a growing DNA strand.
false
If you had a dilution factor of 100,000 and you counted 23 colonies on your plate, what is the bacterial growth?
2.3 x 10⁶ CFU/mL
What is the name for salt-loving bacteria?
halophile
In order to perform a standard plate count, you must make serial dilutions. Which of the following is NOT a step used to prepare for a standard plate count?
dilutions continue until we reach 10ᶟ
When detecting gas production by cells, the gas is collected in small inverted tubes placed in larger tubes of liquid medium containing bacteria.
true
Which of the following are DNA nucleotides? (Select all that apply)
Guanine
Adenine
(Thymine & Cytocine)
If you counted 120 colonies on a plate and had a dilution of 10⁵, what is the count in CFU/ml?
1.2 x 10⁷
What are the 3 parts of a nucleotide?
Sugar
Phosphate
Base
Which is NOT an event that occurs during binary fission?
DNA synthesis occurs during the 5 phase
Where does transcription and translation take place in prokaryotes?
cytoplasm
Most bacteria use carbon as an energy source.
true
In protein synthesis, what type of RNA serves as the template for amino acid sequence?
mRNA
Which of the following pairs are not complementary?
A-G
match the following terms with their definition:
syphilis grow in cultures that contain living human cells
natural media growing in nature in oceans, lakes, and soil
laboratory media synthetic media
what enzyme is responsible for unzipping double-stranded DNA into single strands?
helicase
All bacteria are capable of forming endospores?
false
In DNA replication, which strand is discontinuous?
lagging
Select all of the ways in which bacterial growth can be measured.
Dry wet measurement
Most probable number
What are the 3 types of RNA that participate in transcription/translation? (select 3 answers)
mRNA
tRNA
rRNA
Which of the following is the best definition of generation time?
when a organism divides at its most rapid rate
What method estimates organism numbers by running a known volume of water or air through a filter then growing on a solid medium?
filtration
What is the term for a cloudy appearance indicating the presence of organisms?
turbidity
If you count 52 colonies on a plate and had a dilution factor of 10⁴. What is the count in CFU/ml?
5.2 x 10⁵
I have a pH of a 2 and a pH of a 5. How much more acidic is the 2? (choose the correct answer)
1000x
Which of the following are characteristics of ribosomal RNA? (select all that apply)
This RNA serves as the site for protein synthesis
Eukaryotic ribosomes consist of 40S and 60S subunits
Prokaryotic ribosomes consist of 30S and 50S subunits
Blood agar is often used to observe changes in the appearance of the agar around the colonies growing on this medium. What would we call this type of media?
differential
A facultative organism is one that must have a specified environmental condition
false
What is the stationary phase of cell growth?
when cell division equals cell death
The synthesis of mRNA from DNA is known as translation, and the synthesis of protein from mRNA is transcription.
false
Each tRNA has a three-base ___ that is complementary to a particular mRNA codon.
anticodon
If you had a dilution factor of 100,000 and you counted 7 colonies on your plate, what is the bacterial growth?
7 x 10 CFU/ml
What are the three temperature classifications for bacteria? (select 3)
Thermophiles
Mesophiles
Psychrophiles
The negative stain can be used for what type of cells? (select all that apply)
- Cells that are too delicate to be heat fixed
- Cells that are difficult to stain
- Cells that are being prepared for electron microscopy
When performing the zig-zag method, you must sterilize the inoculating loop between each drag from number to number.
true
How do you determine total magnification of an image with a compound microscope?
Multiply the power of the objective by the power of the eyepiece.
What bacterial sample did you use to inoculate your slant?
Rest of the colony left over from the gram stain
Black absorbs all colors.
true
In the below picture of the microscope, what is the function of the structure indicated by the letter C?
It converges the light beam so they pass through the specimen
What is the 40x objective lens called?
high
What are the two groups that gram staining differentiates between? (select 2 answers)
- Gram negative
- Gram positive
According to proper handwashing guidelines, how much of your hands/arms should you wash?
hands and at least 4 inches above the wrists
What is the purpose of the iodine step in a gram stain?
it fixes the crystal violet to the bacterial cell wall
If you have a 10X eyepiece and a 10X objective lens, what is the total magnification?
100x
In the below picture of the microscope, what is the function of the structure indicated by the letter H?
coarse focus
How do you stop or slow down the growth in a slant?
place in the fridge
If you have properly prepared your nigrosin smear, what color will it be?
When performing the zig-zag method, you should draw your line all the way from 4 back to 1?
false
How long do you need to let an inoculating loop cool after sterilizing in a microincinerator?
What is used as the decolorizer in a Gram stain? (select all that apply)
- Acetone
- Ethanol
What surface does the stain adhere to in a negative stain?
surface of the glass slide
What is the ideal temperature range for growing cultures?
70 - 95F
What is used to prevent a slant from drying out?
screw cap top
What do gram negative cells contain in their cell wall that allows the challenge rinse to penetrate the cell and rinse out the stain?
lipid
Magnification alone is sufficient to achieving a good image under a microscope.
false
You should never leave the flame of a Bunsen burner unattended.
true
All of the cells in a bacterial colony are the same stain
true
In bright field microscopy, a sample’s contrast comes from the scattering of light by the sample.
false
What is standard agar made from?
red algae
What motion are you using to inoculate your slant?
zig-zag
What is the name of the container specialized for growing bacteria?
petri dish
You should clean the lab bench before and after each lab session.
true
When performing a gram stain, how long should you leave the primary stain on the slide?
1 minute
In the below picture of the microscope, what is the function of the structure indicated by the letter G?
it holds the slide and moves it around
Where do you want to store your bacterial to grow?
incubator
In the below picture of the microscope, what is the function of the structure indicated by the letter F?
it connects the body tube to the base
What types of dyes are used for negative stains?
acidic dyes
When performing the zig-zag method, you will close the dish and resterilize the inoculating loop between each line.
true
What dye is used for negative staining?
nigrosine dye
What color is nigrosine dye?
black
Use the picture below along with the dichotomous key to identify the unknown bacterium.
(picture is of red stained circular bacteria)
neisseria meningitides
How do you know when the microincinerator is ready for use?
it will have an orange glow
What types of lenses can be found in a compound microscope? (select all that apply)
- Objective lens
- Ocular lens
How is a slant made?
while liquid agar is still hot, it is poured in a test tube and allowed to solidify in a tilted position
What is the standard growth medium used for culturing bacteria, mold and yeast?
agar
What color are bacteria on a negative stain?
clear/colorless
When should an inoculated slant be placed to grow?
incubator
What is resolving power?
the ability to measure the separation of images that are close together
What is the purpose of solidifying the agar at a slant in the tube?
to increase surface area
Before putting away your microscope, you should rotate the lenses back to the scanning objective.
true
To heat fix cells, you will pass the slide (smear side up) through a flame 2-3 times
true
How should you incubate your slant?
agar up
