BSC 310
Explain why chaperonins are critical to a cell's survival.
Chaperonins aid in the correct folding of proteins, as well as refolding partially denatured proteins
Determine why some prokaryotes have less DNA but more genes than eukaryotes.
Eukaryotes have more introns in their chromosomes
Which of the following is correct for a peritrichous bacterium?
Flagella cover the cell surface.
In sequencing, it may be necessary to find a consensus nucleotide. What does this mean?
It is the nucleotide most commonly found at a particular location.
Which of the following is true regarding the basal body of bacterial flagella?
It may have two or four rings if the bacterium is Gram-positive or Gram-negative, respectively.
What is the function of the parental DNA in replication?
It serves as the template for DNA replication.
Which of the following would be the order at which a facultative organism would break down glucose?
It would first respire glucose in the presence of oxygen and ferment glucose if oxygen is lacking.
Which of the following are terms associated with Okazaki fragments?
Lagging strand, DNA ligase, and discontinuous
Escherichia coli can be grown on a simple defined medium, but Leuconostoc mesenteroides does not grow on this medium. This is because __________.
Leuconostoc mesenteroides requires several nutrients for growth that E. coli does not
Redox reactions in microbial cells require small molecules to serve as electron carriers. An example of an electron carrier is __________.
NAD+
The step in Koch's postulates that most critically enabled him to determine that a particular microbe was the cause, and not an effect, of a particular disease was __________.
cells from a pure culture of the suspected pathogen must cause the disease in a healthy susceptible animal
tight, sticky matrix of either polysaccharide or protein that allows prokaryotes to attach to solid surfaces and protect from dessication
capsule
mitochondria and hydrogenosomes are similar in that they both
carryout the complex oxidation of pyruvate and are sites for aerobic respiration and energy production
communication
cells interact with each other by chemical messengers
metabolism
cells take up nutrients, transform them, and expel waste
motility
cells are capable of self-propulsion
genetic exchange
cells can exchange genes by several mechanisms
evolution
cells evolve to display new properties. phylogenetic trees capture evolutionary relationships
the terms run and tumble are generally associated with?
chemotaxis
Most bacteria require vitamins for their growth. In the cell, vitamins function as __________.
coenzymes
The field of study that can reveal how genes function, reveal how organisms interact with the environment, and show evolutionary relationships is __________.
comparative genomics
a major function of prokaryotic gas vesicles is to
confer buoyancy on cells by decreasing their density
Plasmids function in bacterial cells to __________.
confer to a cell additional genetic traits that are needed only under certain circumstances
Horizontal gene flow can be accomplished in prokaryotes by __________.
conjugation, transduction, and transformation
Which early microbiologist studied the large filamentous sulfur bacterium, later called Beggiatoa?
ferdinand cohn
Which list contains the correct components of a bacterial flagellum?
filament, hook, basal body
numerous filamentous proteins extending from cell that aid in adhesion and pellicle or biofilm formation
fimbriae
lophotrichous
flagella located in a tuft on one end
amphitrichous
flagella located in tufts on both ends
flagellin _____
forms helical chains that make up the filament
which of the following is NOT a function of chaperonins
freeing stalled ribosomes from mRNA
What did supporters of the theory of spontaneous generation declare was needed for life to arise that Pasteur's swan-necked flasks accommodated?
fresh air
Heterotrophic microorganisms acquire their cell carbon __________.
from organic chemicals
The genome sequence of an organism can provide information about the organism's __________.
genes, function, and evolutionary history
While many Archaea are extremophiles, the microbes at Lake Vida are classified as Bacteria. What is the most definitive way that researchers could have determined whether they had found Archaea or Bacteria?
genetic analyses
Arrange the following genetic components in the correct order.
genome, transcriptome, proteome, metabolome
What is the hydrophilic group in bacterial phospholipids?
glycerophosphate
you are given an electron micrograph of a bacterial cell. in the micrograph you can clearly see three thin layers of different densities surrounding the cell. based on the micrograph, you can infer that this cell is _____ and would appear ____ after application of the gram stain procedure
gram negative, pink
Predict which type of organism would be more difficult to treat with antibiotics and why.
gram-negative organisms -- extra layer of LPS
Which of the following terms are mismatched?
gram-negative outer membrane -- teichoic acids
Amphitrichous bacteria ___________________.
have a flagellum at either end of the cell.
bacteria
have peptidoglycan cell walls
neither archaea nor bacteria
have typical membrane-bound organelles
compared to eukaryotes, bacteria and archaea have ___ surface-to-volume ratios, causing ____ nutrient exchange and growth rates
higher, higher
what are the properties of all cells
homeostasis, metabolism, growth, adaptation, response to stimuli, reproduction, evolution
Which of the following are structures that make up the flagella?
hook, basal body, rod, filament
Given that the cytoplasmic membrane has a fluid dynamic nature, with phospholipids and proteins able to move about within the bilayer structure, what force or structure keeps the membrane from falling apart?
hydrophilic/hydrophobic forces
membrane-enclosed organelles, such as nuclei, lysosomes, endoplasmic reticulum, mitochondria, and chloroplasts
increase structural complexity, help eukaryotes overcome diffusion limitation due to their size, and form specialized environments for specific functions to occur
a glycoprotein
is a type of peripheral protein above that can be used as a receptor or in enzymatic functions.
If an arrow were drawn between "DNA" and "mRNA," which of the following would be the best label?
is transcribed into
ATP is an important compound in all living cells. This is because
it is an energy-rich compound that can be broken down to liberate energy for cellular functions
Which of the following is NOT a characteristic of the last universal common ancestor (LUCA)?
its genes were composed of RNA
Which strand will require more RNA primers to complete synthesis?
lagging strand
is the process where one DNA molecule becomes two DNA molecules.
replication
occur in central red region
replication and transcription
genetic
replication, transcription, translation
made of peptidoglycan, enables prokaryotes to withstand high pressures without lysing
thick cell wall
Which structural feature of Gram-positive bacteria enhances their ability to retain the crystal violet dye?
thick peptidoglycan layer
In E. coli, the consensus sequence for the Pribnow box (the -10 sequence) is TATAAT. Therefore, __________.
this will be the strongest -10 promoter sequence
Specify why is it necessary to use stains to view microorganisms.
to increase the contrast and make the cells more visible
In bacteria, which of the following enzymes must act to separate (or unlink) daughter chromosomes following replication?
topoisomerase IV
is the process where information carried by DNA becomes mRNA
transcription
Which of the following are the correct sequential processes involved in protein synthesis?
transcription and translation
is the process where information carried by mRNA is made into a functional protein.
translation
occurs in the polar green regions.
translation
which of the following types of microscopy could be used to visualize the layers of the cell membrane and the cell wall
transmission electron microscopy
integral proteins are mostly involved in
transport function
Which of the following bacteria would have axial filaments?
treponema spirochetes in a syphilis chancre
according to our present understanding, each of the three major domains of life arose from a single last universe ancestor
true
although archaea cell walls are quite variable among species, the presence of a s-layer is the most commonly observed across the domain
true
atp-binding cassette transport systems have high substrate affinity and thus help microorganisms survive in low nutrient environments
true
bacteria containing endospore formation makes it more resistant to heat and uv light compared to a bacteria that doesn't
true
confocal scanning laser microscopy couples a computerized microscope, laser light source and fluorescent dye(s) to visualize microorganisms
true
mitochondria and chloroplasts have their own DNA and ribosomes, which supports the endosymbiosis hypothesis
true
poly-beta-hydroxybutyric acid (phb) is a carbon- and energy-storing polymer
true
resolution of a microscope is best described as the ability to distinguish 2 adjacent objects as separate and distinct
true
slimelayers, fimbriea and pili can all aid bacteria in sticking to surfaces
true
type IV pili is associated with an microorganism exhibiting twitching motility
true
5th step in RNA processing
the completed messenger RNA leaves the nucleus
For most compounds, the free energy Gf0 is negative. This means that __________.
the compound can form spontaneously from its elements
In E. coli, what two promoter regions are recognized by the s70 subunit?
-10 and -35
Flagellar motility is widespread in both Archaea and Bacteria. The introductory passage references findings that some archaeans (Methanocaldococcus) swim faster than E.coli bacteria, and some (Halobacterium) are slower. The wide range of speeds may indicate that flagellar motility is an example of convergent evolution. What are some other similarities or differences between archaeal and bacterial flagella?
-Archaeal flagella are made of flagellin proteins unrelated to those seen in bacterial flagella. -Archaeal flagella are powered directly by ATP, but bacterial flagella are powered by a proton-motive force. -Archaeal flagella are about half as wide as bacterial flagella.
What are the benefits of polycistronic mRNA to bacterial cells?
-Bacteria can quickly utilize multiple different metabolic resources -All of the proteins for a single enzymatic pathway will be coordinately available
Both prokaryotic cells and eukaryotic cells require ribosomes for translation and the synthesis of proteins. Why is the bacterial ribosome an excellent drug target?
-Ribosomes are involved in protein synthesis that facilitate bacterial survival and may produce disease-causing toxins. -The ribosomes of bacterial cells have a distinct structure from those in eukaryotic cells.
A bacterium tumbles ___________________.
-more frequently as it moves toward a negative stimulus. -when the flagella rotate clockwise.
As a rule of thumb, what is the lower size limit for bacterial cells?
200 nm
how many bases make up a codon
3
In which direction does DNA polymerase synthesize DNA for the lagging strand?
5' to 3'
ribosomes move along the mRNA in which direction?
5' to 3'
What would happen if the DNA sequence that coded for Cys was mutated in the third position from a U to an A?
A stop codon would be introduced prematurely.
Why is ATP necessary for active transport?
ATP provides energy to transfer material against its concentration gradient.
What would you anticipate seeing if you accidentally switched crystal violet and safranin while performing a Gram stain?
All bacteria would appear purple.
Which of the following is NOT an important infectious disease in the developing world today?
Alzheimer's disease
Why is DNA replication essential for a cell?
An organism must copy its DNA to pass genetic information to its offspring.
Some viruses have a genome consisting of double-stranded RNA. How could you distinguish between the genome of this virus and a virus containing double-stranded DNA?
Analysis of the genome sequence would reveal different nitrogenous bases in the RNA virus as compared to the DNA virus.
Which of the following is NOT part of the endospore structure?
B form DNA
How is bacterial translation different from eukaryotic translation?
Bacteria can begin translation before transcription has terminated.
Hypothesize the most plausible reason why scientists accepted spontaneous generation for so many years.
Biology was primarily an observational science for many hundreds of years until the acceptance of the scientific method.
DNA and RNA share which of the following characteristics?
Both are made, in part, of nitrogenous bases and sugars.
What characteristic of DNA allows two connected DNA polymerases to synthesize both the leading and lagging strands?
DNA is flexible
The molecule that seals the gaps between the pieces of DNA in the lagging strand is
DNA ligase
Which enzyme joins the gaps between synthesized DNA fragments of the lagging strand?
DNA ligase
Which statement about DNA replication is FALSE?
DNA ligase adds nucleotides to the lagging strand.
Which statement illustrates why DNA polymerase cannot initiate a new DNA strand?
DNA polymerase requires a free 3′-hydroxyl group to add nucleotides.
Which of the following build(s) new strands of DNA?
DNA polymerases
Which protein must first bind to the origin of replication for DNA synthesis to begin?
DNAa
Newer sequencing techniques require only one lane on an electrophoresis gel rather than four. How is this possible?
Each base is identified with a different fluorescent color.
The ion torrent sequencing method uses "the world's smallest pH meter" to detect the addition of bases. What change related to pH would be measured?
Each time a new base is added, an H+ is removed. A pH meter would record an increase in H+ concentration in the environment as a decrease in pH (greater acidity).
Which statement illustrates how the development of enrichment culture techniques by Beijerinck contributed to our knowledge of microbial diversity?
Enrichment culture technique allows targeting of specific metabolic groups by using selective nutrients and incubation conditions.
Which statement best illustrates the importance of a high surface-to-volume ratio that is found in microorganisms?
If a cell has a high surface-to-volume ratio, there will be enough surface area to get the needed nutrients in to support cellular metabolism and the accumulated waste out.
Horizontal gene transfer refers to the transfer of genes from one organism to another, as occurs during conjugation between bacteria. How does this differ from vertical gene transfer?
In horizontal gene transfer, genes are transferred from one mature adult organism to another. In vertical gene transfer, genes are transferred from adults to offspring.
Differentiate between industrial microbiology and biotechnology.
Industrial microbiology uses naturally occurring microbes to make low-value products, while biotechnology uses genetically engineered microbes to make high-value products.
Predict why dipicolinic acid is only found in endospores and not vegetative cells.
It binds free water and aids in dehydration, which would be detrimental to vegetative cells.
Which of the following statements about a gram-negative cell wall is true?
It contains ketodeoxyoctonate (KDO).
Why is having few or no inteins related to having a very small genome?
Organisms with very small genomes tend to have essential genes with minimal additional material.
If an E. coli cell has a surface area-to-volume (S/V) ratio of 4.5, and a Pelagibacter ubique has an S/V ratio of 22, which cell will be able to exchange nutrients and wastes with the environment more efficiently?
Pelagibacter ubique, because its cells are smaller
You are interested in trying to determine the function of a particular gene in a common bacterium (meaning that it has a haploid genome). To do this, could you use a knockout mutation?
Possibly; it would depend on whether the gene was essential for survival and on whether you could create a diploid bacteria as well.
Why must primase be used before DNA polymerase when replicating DNA?
Primase provides an RNA primer with a 3' end on which DNA polymerase can act.
In DNA replication in vivo, RNA primers are used. However, researchers use DNA primers instead in the lab because DNA primers are more stable. Why might this be the case
RNA has a relatively short half life compared with DNA and does not need to be as stable to perform its functions in the cell.
which of the following makes mRNA from the information stored in a DNA template?
RNA polymerease
How do eukaryotic flagella differ from prokaryotic flagella?
The filament of a eukaryotic flagellum is covered by a membrane.
During DNA replication, which nucleotide will bind to an A nucleotide in the parental DNA?
T
What nucleotides would DNA polymerase add if it encountered the nucleotide sequence: ATTGC?
TAACG
Given the following DNA sequence (5' ( 3'), what would be the DNA sequence on the complementary strand (3' ( 5') of a double-stranded helix molecule? DNA sequence: AGTCCGA
TCAGGCT
Researchers discover a new species of bacterium that has an unusual metabolism. However, it has biochemical and morphological similarities to other species. What is the most comprehensive and effective approach to determine how to classify these bacteria?
The bacteria should be classified by using genomic analyses to construct phylogenies.
How does a bacterium "know" when a light source is present?
The bacterium contains receptors that are sensitive to the light.
How do polysomes illustrate the energy efficiency of a cell?
The cell can synthesize multiple copies of a protein from a single piece of mRNA
Why is no energy required in passive transport?
The concentration gradient drives the movement.
Which statement about DNA replication is CORRECT?
The leading strand is built continuously, and the lagging strand is built in pieces.
Functional analysis of the genome of a prokaryote shows that 20% of the genome is for metabolism, 1 % biosynthesis of amino acids, 8% peptide ABC transporters, and 2% replication. What can you determine about the environment this organism lives in?
The organism lives in an environment rich in organic material, particularly amino acids and proteins.
What is the second of Koch's postulates?
The organism must initially be cultivated in pure culture away from the animal body.
Which statement illustrates how prokaryotes determine where to begin translation so the correct protein is synthesized?
The rRNA recognizes the correct start codon with the aid of an upstream Shine-Dalgarno sequence
Explain why promoters for the same sigma subunit do not have identical sequences in all organisms.
The sequences within the promoter region at -10 and -35 are the most important for recognition by the sigma subunit.
Why is the DNA synthesis of the lagging strand considered discontinuous?
The synthesis is moving in the opposite direction from the replication fork.
Explain why the presence of a capsule or slime layer would benefit a bacterial cell.
These outer layers can aid in attachment to solid surfaces.
What is the function of the connector proteins?
They link the leading strand DNA polymerase and the lagging strand DNA polymerase together.
Which of the following amino acids is coded by only one codon?
Trp
Two capillary tubes were immersed in a suspension of motile bacteria. After 10 minutes, the capillary tubes were removed and the number of bacteria in the capillary was counted. Tube A contained 105 bacteria/ml, whereas Tube B contained 1000 bacteria/ml (the same concentration as the original suspension of bacteria). Which of the following statements best describes these results?
Tube A contained an attractant and Tube B contained a buffer control.
What are the products of semiconservative replication for a double-stranded DNA molecule?
Two double-stranded DNA molecules, each consisting of one parental strand and one daughter strand.
Which of the following statements regarding bacterial flagella is true?
When the flagellum or flagella rotate counterclockwise, the bacterium runs.
The replisome is a large complex of proteins that contains many enzymes involved in DNA replication. Hypothesize why these enzymes do NOT function independently of each other.
With the replisome, it can replicate both strands of DNA at the same time.
Which of the following scenarios would be considered bacterial motility?
a bacterium swimming away from a high concentration of a toxic compound
Based on your understanding of the chapter material and the information in the passage, the speed of Bacteria and Archaea is determined by:
a combination of structural, functional, and environmental factors.
With what does the initiation of protein synthesis in Escherichia coli always begin?
a free 30S ribosomal unit
Proofreading of newly-synthesized DNA is important because __________.
a high fidelity in the copying of DNA is necessary for good heredity
the cytoplasmic membrane could best be described as
a highly selective permeability barrier
1st step in RNA processing
a modified guanine nucleotide is added to the beginning of the RNA strand as a cap
As a researcher you find a strain of E.coli that produces a colicin, which acts on various pathogenic strains of E. coli. On what type of genetic element would you expect to find its gene?
a plasmid
In addition to an inverted repeat sequence in the DNA that leads to a stem-loop structure in the RNA, what is the other primary feature of an intrinsic transcriptional terminator?
a series of A residues
To determine if you have identified a functional open reading frame (ORF), you should have found within the sequence __________.
a start codon and a ribosomal binding site (RBS)
Which of these organisms is likely to have the largest genome?
a yeast cell
The main functions of the bacterial cell wall include all but the following __________.
actively transporting solutes against the concentration gradient
What is a major advantage of gas vesicle production?
allows cells to control their vertical position in the water column to maximize photosynthesis
Bacteria with ___ arranged flagella change direction by periodically stopping to reorient themselves or by changing the flagellar rotation.
amphitrichously
Which type of active transport protein uses one protein to pump two different molecules?
antiport and symport
Defined culture media __________.
are made by adding precise amounts of purified organic and inorganic chemicals to distilled water
GAU codes for
aspartic acid
you isolate an organism from the environment and discover it uses hydrogen sulfide as its energy source, oxygen as its terminal electron acceptor and carbon dioxide as its source of carbon, it is a _____
autotroph
the use of the gram stain in microbiology is important because it differentiates
bacterial cells with different types of cell walls
Chromosomal islands are similar to plasmids __________.
because both elements contain nonessential genes
Teichoic acid molecules in Gram-positive cell walls include phosphate groups. Therefore, they will __________.
bind positive ions like Mg2+ and Ca2+
The enzyme lysozyme kills bacterial cells by cleaving the β-1,4-glycosidic bonds in the peptidoglycan. This leads to which of the following?
breaches of the cell wall and cell lysis due to osmotic swelling
how does water enter and exit a cell
by simple diffusion or by use of an integral transport protein
chemical structure of archaea phospholipid
c-o-c-r | r
Microorganisms that are fastidious, that is, difficult to grow, __________.
can be grown with the addition of nutrients such as serum to a complex medium
Pathogenic bacteria _______________________
can be identified and classified by differences in their flagellar proteins.
Microbes evolve specific traits that increase their fitness in specific environments. Martinus Beijerinck developed the enrichment culture technique to isolate microbes from complex natural samples, like soil and water, by manipulating the __________.
culture conditions and nutrients
What type of microscope would you use if you are viewing a light specimen on a contrasting background?
dark-field microscope
Staining increases the visible contrast of cells compared with the background. Because the Gram stain results in some types of bacteria staining purple, and other types appearing pink, this is called a __________ stain.
differential
properties of some cells
differentiation, communication, genetic exchange, and motility
Which of the following RNA molecules in NOT found in translation?
dsRNA
Gene duplication is essential to organisms because __________.
duplicate genes are free to evolve into new genes
Identify which situation would be harmful rather than beneficial.
e. coli in ground meat
Which of the following processes generates ATP through oxidative phosphorylation?
electron transport chain
Identify which of the following is a major function of the cytoplasmic membrane.
energy conservation
In addition to being the boundary between the external environment and the inside of the cell, in prokaryotes the cytoplasmic membrane also functions in which of the following?
energy conservation reactions
catalytic
energy, biosynthesis
Transport proteins can become saturated with solute, have high specificity for certain substances, undergo conformational (shape) changes, and are highly regulated by the cell. What other type of cellular proteins have these four general characteristics?
enzymes
Which of the following would be an example of applied microbial research?
experiments that test a hypothesis to improve wastewater treatment
4th step in RNA processing
extra adenine nucleotides are added to the end of the RNA strand, forming a tail
all membrane proteins are involved in membrane transport
false
all microorganisms require molecular oxygen to carry on life functions
false
archaea is a domain of life characterized by cells containing a membrane-enclosed nucleus and other subcellular organelles including mitochondia
false
both hydrophilic and charged molecules readily diffuse through the cytoplasmic membrane
false
chemotaxis is a sensory response that does not effect the rotational direction of the flagellar motor
false
electron microscopes have less resolving power than light microscopes
false
in general, swimming is performed with pili, whereas gliding uses other cellular components such as flagella
false
most microorganisms are pathogenic
false
Which DNA strand is synthesized continuously?
leading strand
confers strength and protection and is toxic to many animals because of its lipid A component
lipopolysaccharide layer
Which of the following attaches the outer membrane to peptidoglycan?
lipoprotein
Which of the following refers to a bacterium with a tuft of flagella at one end of the cell?
lophotrichous
Which of the following can be translated into protein?
mRNA
Which of the following is NOT a molecule found during DNA replication?
mRNA
Transcription produces which of the following?
mRNA, tRNA, and rRNA are all produced by transcription.
Although the existence of microorganisms was surmised long before, their discovery depended upon a technological development (the microscope) in order for scientists to __________.
make direct observations of microbes
applied microbiology deal with important practical problems in
medicine, agriculture, and industry
In both Bacteria and Archaea, fatty acids are important components of __________.
membranes
Like all forms of life on Earth, all microbial cells perform three major types of activities: __________.
metabolism, growth, and evolution
the start codon also codes for which amino acid?
methionine
which of the following statements is false?
microbial cells include both bacteria and viruses
the largest mass of living material on earth comes from
microorganisms
Once equilibrium is reached,
molecules move, but there is no net movement in a particular direction.
peritrichous
multiple flagella, all over the cell
What is the predominant type of supercoiling in Bacteria?
negative supercoiling
Consider the following two statements: Because viruses are acellular, they do not contain genes. In most cases, prokaryotes contain a linear chromosome.
neither statement
growth
nutrients from the environment are converted into new cell materials to form new cells
chemical structure of bacteria and eukarya phospholipid
o || c-o-c-r | r'
Pasteur's experiments refuting the theory of spontaneous generation were crucial to the advancement of the field of microbiology because they led to the development of all EXCEPT which of the following? a- the germ theory of disease b- optical isomers c- sterile technique d- food preservation
optical isomers
LUCA sequence
origin of earth (4.6 bya)-->origin of cellular life (4 bya)-->anoxygenic phototrophic bacteria --> origin of cyanobacteria-->modern eukaryotes-->humans
Arrange Koch's postulates in the correct order.
pathogen present in all cases of disease; pathogen isolated in pure culture; pathogen able to infect healthy host; pathogen re-isolated
gel-like space with hydrolytic enzymes for nutrient transport and chemoreceptors to direct movement
periplasm
Bacteria with ____ arranged flagella change direction by changing the flagellar rotation and "tumbling."
peritrichously
Which type of microscopy would NOT produce three-dimensional images of microscopic specimens?
phase contrast microscopy
Genetic information in the cell is carried by information molecules, including all EXCEPT which of the following? -rna -dna -polypeptides -phospholipids
phospholipids
filamentous proteins extending from the cell with various functions such as conjugation, transformation, and twitching motility
pili
Match the bacterial genetic element with the correct characteristic
plasmid -- nonessential genes
n general, ___ flagellated organisms move more quickly than peritrichously flagellated organisms.
polarly
As with other bacteria, many genes on the E. coli chromosome are found in functional clusters that are transcribed into a single mRNA. What are these mRNA molecules called?
polycistronic mRNA
What results from the process of translation?
polypeptide
Which of the following terms describes a group of cells derived from one "parental" cell?
population
Which of the following terms refers to a bacterium moving toward a carbon source for food?
positive chemotaxis
Which of the following would not move freely across the cytoplasmic membrane?
positively charged hydrogen ions
In Sanger sequencing and in many newer sequencing techniques, labeled precursors are used. What are these precursors?
primers or nucleotides that will be incorporated into the newly synthesized DNA
basic microbiology can be used to
probe the fundamental process of life, study characteristics of cells of multicellular organisms, and model our understanding of cellular processes in multicellular organisms, including humans
Which of the following is NOT included in the genome?
proteins
The energy conservation feature of the bacterial cytoplasmic membrane is based on the low diffusion of which chemical?
protons
Following the Gram stain procedure, gram-positive bacteria appear __________.
purple
What are the products of glycolysis?
pyruvate, ATP, and electron carriers
Ribosomes contain which of the following?
rRNA
A student observed a stained specimen of bacteria using bright-field microscopy. At 100x magnification, there appeared to be only one cell in the field of view, but at 1000x it was clear that there were two cells close together. The ability to distinguish these two cells as separate entities is called __________.
resolution
All life on Earth can be divided into three main Domains, the Bacteria, the Archaea, and the Eukarya, based on the similarities of their __________.
ribosomal RNA
Which of the following is NOT a new subdiscipline that has been created from the study of genomes?
ribosomics
Bacteria _______________________
rotate the flagella 360 degrees to move through their environment.
interlocking molecules of protein or glycoprotein that prevents osmotic lysis and acts as a semipermeable barrier
s-layer
Bacteria can have positive, neutral, or negative effects on humans and other macroorganisms. Which of the following would be a negative association?
salmonella bacteria in the human gut
Polypeptides and proteins must fold properly to be functional. Hydrogen bonds between the oxygen and nitrogen atoms of the peptide bonds are crucial to which level of protein structure?
secondary structure
2nd step in RNA processing
segments of the RNA strand that do not actually code for the protein are removed
3rd step in RNA processing
segments of the RNA that do code for the protein are reconnected
DNA replication is sometimes also called __________.
semiconservative replication
Which statement best describes an operon?
several genes, next to each other in prokaryotic DNA, that are transcribed as a single piece of mRNA
A plasmid differs from the bacterial chromosome in that it is __________.
significantly smaller
How many codons code for the amino acid arginine?
six
The cytoplasmic membrane is termed "semi-permeable" because some substances, like water and alcohols, can pass freely through while others, like sugars, amino acids, and ions, cannot. What molecular characteristics largely determine whether or not a substance can pass through the membrane?
size and hydrophobicity
loose, easily deformed, sticky matrix of either polysaccharide or protein that allows prokaryotes to form biofilms and avoid dehydration
slime layer
both archaea and bacteria
some are extremophiles, most have single and circular main chromosomes, may have small circular pieces of DNA called plasmids
differentiation
some cells can form new cell structures such as spores
Explain the germ theory of disease.
some microorganisms can cause disease
which is a valid cell morphology
spirochette
Consider the following two statements about microorganisms and their environments: I. Aerobic organisms maintain oxygen in their environment. II. Some microorganisms consume the waste products of another population as nutrients.
statement II
Which of the following would be an example of basic microbiology research?
studies on how cells respond to DNA damage by triggering a repair pathway
Which type of active transport protein moves two molecules into the cell at the same time?
symport
The proton motive force is generated by the movement of electrons across a membrane, so that the two sides of the membrane differ in both charge and pH. This proton motive force is essential for which of the following?
synthesis of ATP
The process of synthesizing proteins involves translating one "language," nucleic acid sequences, into another "language," amino acid sequences. The cellular component that does the actual translating from codons to amino acids is the __________.
tRNA
Which of the following is involved in bringing amino acids to the ribosomes?
tRNA
The presence of which of the components listed below would allow you to distinguish between a gram-positive or gram-negative cell wall?
teichoic acids -- gram-positive
motility is
the ability of an organism to move by itself
When a bacterial flagellum turns clockwise, ______________________.
the bacterium "tumbles."
Mycoplasma species are bacteria that do not possess a cell wall. What accounts for the extra strength and rigidity of a mycoplasmal cell membrane?
the presence of sterols in their membranes
The first step of translation begins when __________.
the ribosome binding site (RBS) on the mRNA binds to the 16S rRNA to begin the formation of the initiation complex
Transport proteins (transporters) require energy expenditure for each molecule of substrate transported. The reason for this energy requirement is __________.
the solute must be transported against a concentration gradient
In addition to completing the oxidation of glucose during respiration, the citric acid cycle is important for which of the following processes?
the synthesis of amino acids using α-ketoglutarate and succinate as precursors
The resolving power of an electron microscope is much greater than that of the light microscope because __________.
the wavelength of electrons is much shorter than the wavelength of visible light used in a light microscope
What plantlike characteristic do chemolithotrophs possess?
they are autotrophs
what is the biological function of endospores
they enable organisms to endure extremes of temperature, drying, and nutrient depletion
What makes phospholipid membranes good at keeping some molecules out, and allowing others to freely pass?
they have hydrophilic and hydrophobic regions
deduce why viruses are excluded from ribosomal RNA-based tree of life
they lack ribosomal DNA
reasons why a virus is not considered living
they lack their own metabolism, protein synthesis machinery, not motile, and neither communicate nor differentiate
Enzymes are cellular catalysts. This is because __________.
they lower the activation energy of a reaction, thereby increasing its rate
Some bacteria can carry out interesting and important metabolisms not found in any macroorganism. Many of these reactions are crucial to life on Earth because __________.
they recycle elements needed by living organisms
Which transport protein employs transporters that move molecules only in one direction?
uniport and symport
Archaea have
unique cell wall structure lacking peptidoglycan, cellulose, or chitin
DNA polymerase can only add nucleotides to a free 3(-hydroxyl group on a nucleic acid strand. As a consequence, all EXCEPT which of the following statements are true of DNA replication?
uracil is not found in DNA
Who isolated in pure culture the first nitrogen-fixing bacterium?
winogradsky
When does evidence suggest that life first arose on Earth?
~ 3.8 × 109 years ago
