Microbio SuperSet 2
What are the functions of the enzyme gyrase and topisomerase?
Gyrase and topisomerase remove supercoils by cutting the DNA, rotating the cut ends in the direction opposite of the supercoiling, and then rejoining the cut ends.
What provides electrons for the light reactions? -H2O -CO2 -The Calvin cycle -O2 -Light
H2O
In oxygenic photosynthesis, cyanobacteria, algae, and green plants replenish electrons to the reaction center by dissociation of ___________ molecules, resulting in the release of ___________ molecules
H2O;O2
a high efficiency particulate air filter that removes particles, including microbes, from intake or exhaust air flow
HEPA filter
What is a retrovirus type that can make reverse transcriptase enzyme?
HIV
Staphylococcus aureus
Halophile, Gram positive cocci cluster skin infection (boils, impetigo), deep infection (wound infection, bacteremia, osteomyelitis, necrotizing pneumonia), toxic shock, scalded skin, food poisoning; gram + cocci, catalase-positive, coagulase-positive, β-hemolytic; found in anterior nares of ~30% of healthy individuals
Soaps
Have Hydrophilic and Hydrophobic ends; good Degerming agents, but not Antimicrobial
Griffiths transformation experiment
He gave mice an infectious strain of bacteria, and a non infectious type of bacteria. the mice died from being directly injected with the infectious strain. Heat kill the infectious strain, the mice does not die. Mix the heat killed strain with the non infectious strain and then injected it into the mouse, the mouse died. Conclusion: the uninfectious bacteria uptake some genetic material required to make the infectious bacteria.
Thimerosal
Heavy metal used to preserve vaccines
Copper
Heavy metal which controls algal growth in reservoirs, fish tanks, swimming pools, and water storage tanks; interferes with chlorophyll
Example of micoaerohiles?
Helicobacter pylori
what is an example of successful subunit vaccine?
Hepatitis B
What is heterochromatin?
Heterochromatin is tightly packed inactive DNA.
What is the function of histones?
Histones stabilize and package DNA to form nucleosomes connected by linker DNA.
Explain diabetes using the term homeostasis
Homestasis control things within a window, so individual deficient in homeostasis of blood sugar or glucose in blood
alone or together in Quaternary Protein Structures
How can polypeptides released at the Termination stage of Translation function?
Number of Base Pairs (= # of nucleotides)
How is the length of a DNA molecule usually expressed?
An example of protein synthesis is the production of_enzyme
Human Growth hormone
A proton gradient is an electrochemical gradient of ______________ ___________across a membrane.
Hydrogen ions
examples of chemoautotrophs
Hydrogen, sulfuer, and nitrifying bacteria, some archaea
Beta-oxidation is a catabolic process in which enzymes split pairs of _____________ carbon atoms from fatty acid and join them to coenzyme A to form acetyl-CoA.
Hydrogenated
What is the most reactive of the 4 toxic forms of oxygen?
Hydroxyl radical
In eukaryotic DNA replication, what is the role of alpha DNA polymerase?
IN eukaryotic DNA replication, alpha DNA polymerase initiates replication, including synthesis of a primer.
Why are redox reactions considered coupled reactions? -Because they involve both the Krebs cycle and the electron transport chain, redox reactions are said to be coupled. -Electrons are always passed in pairs. -Because they affect both the charge and the structure of molecules, redox reactions are said to be coupled. -If an electron is transferred between molecules, one molecule is oxidized while the other molecule is reduced.
If an electron is transferred between molecules, one molecule is oxidized while the other molecule is reduced.
What happens if temperature is too high in membranes?
If too high, membranes become too fluid and cannot contain the cell or organelle
What happens if the temperature is too low in membranes?
If too low, membranes become rigid and fragile
Specialized Transduction
Important in transferring Genes that code for some bacterial toxins-- those causing Diphtheria, Scarlet Fever, and severe diarrhea of E. coli
methylated
In Bacteria, Adenine Bases are usually _________; meaning CH3 is added to one or two Nitrogen Bases in a specific Nucleotide sequence
c
In DNA, adenine forms __________________hydrogen bonds with _________________. a. three / uracil b. two / uracil c. two / thymine d. three / thymine
copies of the RNA
In Elongation of RNA Transcription, many Polymerase molecules may concurrently transcribe the same genes, forming ______ __ ___ ___.
Plant and Animal Cells
In Eukoaryotes, what kinds of cells methylate only Cytosine Bases?
1-2 distinct chromosomes
In Prokaryotes, the main portion of DNA, along with associated Proteins and RNA (which holds the DNA in place) is packaged in what?
Shorter
In Synthesis of the Lagging strand in Eukaryotes, the Okazaki Fragments are _________; only about 100-400 Nucleotides long
What is a sigma factor?
In bacteria, a polypeptide subunit of RNA polymerase called the sigma factor is necessary for recognition of promoter
In eukaryotic transcription, what is capping?
In capping, a modified guanine nucleotide is added to the 5' end of the mRNA
What differentiates eukaryotic mitochondrial and chloroplast DNA from eukaryotic nuclear DNA?
In contrast to linear nuclear DNA, eukaryotic mitochondria and chloroplast DNA is circular.
In eukaryotic DNA replication, what is the function of epsilon DNA polymerase?
In eukaryotic DNA replication, epsilon DNA polymerase is responsible for replicating the lagging strand.
In eukaryotic DNA replication, what is the function of gamma DNA polymerase?
In eukaryotic DNA replication, gamma DNA polymerase replications mitochondrial DNA.
IN eukaryotic DNA replication, what is the function of sigma DNA polymerase?
In eukaryotic DNA replication, sigma DNA polymerase elongates the leading strand.
In genetics, a palindrome is a region of DNA in which the sequence of nucleotides is _____________.
In genetics, a palindrome is a region of DNA in which the sequence of nucleotides is identical to an inverted sequence. E.g., GAATTC on the top strand is the palindrome of CTTAAG on the bottom strand. GAATTC| |GAATTC CTTAAG| |CTTAAG -------------------------- (IR) transposase (IR) gene
How does DNA methylation play a role in the initiation of DNA replication?
In many bacteria, methylated nucleotide sequences play a role in initiating DNA replication.
In eukaryotic transcription, what is polyadenation?
In polyadenation, 100-250 adenine nucleotides are added to the 3' end
Describe how DNA packaging in eukaryotes differs from DNA packaging in prokaryotes
In prokaryotes DNA is packaged in a chromosome and located in the cytoplasm of the cell. Regions of DNA called operons respond to chemical signals in the cell and direct which genes will be transcribed. In eukaryotes DNA is wrapped around histone proteins to form nucleosomes that are compacted into chromatin fiber. The genes must be unwound by chromatin modifying enzymes and exposed to RNA polymerase in order for transcription to begin.
operon
In prokaryotes, a region of DNA that includes a promoter, an operator, and one or more structural genes that code for proteins needed to do a specific task
Where does transcription occur prokaryotes?
In prokaryotes, transcription occurs in the nucleoid.
How does DNA methylation play a role in the control of genetic expression?
In some cases, genes that are methylated are turned off and are not transcribed, whereas in other cases methylated genes are turned on and transcribed?
highest
In the Use-dilution test, the most effective agent entirely prevents microbial growth at the _________ dilution.
How does the action of primase differ in the lagging strand as compared to the leading strand?
In the lagging strand, primase synthesizes RNA multiple primers - one every 1000 to 2000 DNA bases of the template strand.
where do you insert DNA in the gel electrophoresis technique?
In the sample wells (small holes cut into agarose gel) near the negative plaque
What is the function of primase?
In the synthesis of the LEADING strand, primase synthesizes short RNA molecules that are complementary to the template DNA strand.
What is the function of the RNA primer?
In the synthesis of the LEADING strand, the RNA primer provides the 3' hydroxyl group required by
In the synthesis of the lagging strand, what is the function of DNA ligase?
In the synthesis of the lagging strand, DNA ligase seals the gaps between the adjacent fragments to form a continuous DNA strand.
In the synthesis of the leading strand, what is the function of DNA polymerase I?
In the synthesis of the leading strand, DNA polymerase I replaces RNA primer with DNA.
In the synthesis of the LEADING strand, what is the function of DNA polymerase III?
In the synthesis of the leading strand, DNA polymerase III covalently joins deoxyribonucleotides one at a time. It can add about 500 to 1000 per second.
In addition to it's main function, DNA polymerase III also performs a secondary function in the synthesis of the leading strand. What is it?
In the synthesis of the leading strand. DNA polymerase III performs a proofreading function.
d
In translation, the site through which tRNA molecules leave a ribosome is called the a. A site b. X site c. P site d. E site
Nucleus (mainly in the nucleoli)
In what part of the Eukaryotic cell does most Transcription take place?
Chromosomes and Plasmids
In what two structures are prokaryotic genomes contained?
Antimicrobials
Include Antibiotics, semisynthetic, and synthetic chemicals
Base Pair Mutations
Include base pair substitution, which a new base pair is replaced with another one, can change the whole meaning of the code. Ex: THECATATEELK, sub: THERATATEELK. Results: silent-no change, missense-amino acid sub may affect function, nonsense-mutation changes regular codon to stop codon
Factors affecting the efficacy of antimicrobial methods
Includes: The nature of the site to be treated, the degree of susceptibility of microbes involved, and environmental conditions that pertain
Bacterial growth is defined as......
Increase in bacterial cell population.
How does indirect selection work?
Indirect selection involves isolating mutant phenotypes on the basis that they are auxotrophs.
Name the steps of transcription in order
Initiation, Elongation, Termination
Life cycle of bacteriophage
Injects DNA into the cell, phage enzymes degrade host DNA, cell synthesizes new phages that incoporate phage DNA and mistakenly some host DNA
In photophosphorylation, ADP is phosphorylated with organic or inorganic phosphate?
Inorganic
Recombinant approach
Insert gene into vector
Frame Shift Mutations
Insertion or deletion of a base pair, everything is thrown off by one. Results in missense and nonsense mutations
Mutagens
Ionizing Radiation, Nonionizing Radiation, Nucleotide Analogs, Nucleotide-Altering Chemicals, and Frameshift Mutagens
Reverse transcriptase is isolated from what organism? (specify if their genome is of DNA or RNA)
Isolated from retroviruses (RNA genomes)
Which of the following best describes the function of a photosystem? -It absorbs light energy and converts it to ATP and NADPH. -It generates a proton gradient in order to produce ATP and NADH. -It generates glucose from carbon dioxide and water. -It generates NADH and FADH2 from the oxidation of acetyl-CoA
It absorbs light energy and converts it to ATP and NADPH
Describe the function of a photosystem?
It absorbs light energy and converts it to ATP and NADPH.
How can a noncompetitive inhibitor affect enzyme activity without binding to the active site? -It alters the shape of the substrate, making it difficult for it to bind to the active site. -It physically blocks the entrance to the active site. -It binds to another location on the enzyme, altering the active site shape. -It degrades the substrate.
It binds to another location on the enzyme, altering the active site shape.
What is the fate of dihydroxyacetone phosphate (DHAP) in glycolysis? -It is directly involved with the reduction of NAD+ to NADH. -It is converted to fructose-1,6-bisphosphate. -It phosphorylates ADP to ATP. -It is converted to glyceraldehyde 3-phosphate (G3P).
It is converted to glyceraldehyde 3-phosphate (G3P).
what is one difference between the streak and pour plates methods?
It is that colonies form both at and below the surface of the medium in pour plates method
Why is ATP used in the preparatory stage? -It is needed to produce water from the energy-conserving stage. -It is needed to reduce NAD+ to NADH. -It makes the process of converting glucose into two 3-carbon molecules easier. -ATP is needed to allow the cell to move toward a carbon source.
It makes the process of converting glucose into two 3-carbon molecules easier.
What is the purpose of the Calvin-Benson cycle? -It produces glyceraldehyde-3-phosphate by fixation of CO2 molecules. -It forms phosphorylated pentose sugars from glucose-6-phosphate. -It catabolizes glucose to pyruvic acid using enzymes different from those used in glycolysis. -It transfers an amine group from one amino acid to another.
It produces glyceraldehyde-3-phosphate by fixation of CO2 molecules.
What is the primary function of fermentation? -It is a metabolic pathway used to produce organic acids, like lactic acid. -It is an alternative way for a cell to produce carbon dioxide. -It provides the cell with a mechanism to regenerate the oxidized form of electron carriers, allowing glycolysis to continue. -It enables the electron transport chain to continue functioning in the absence of oxygen.
It provides the cell with a mechanism to regenerate the oxidized form of electron carriers, allowing glycolysis to continue
What is the major function of fermentation? It generates a proton gradient. it regenerates NAD+ for glycolysis. It produces ADP. It reduces glucose
It regenerates NAD+ for glycolysis
What is the major function of fermentation?
It regenerates NAD+ for glycolysis.
Why is NADH an important growth factor for microorganisms?
It serves as an electron carrier in energy-producing pathways.
What are jumping transposons?
Jumping transposons move from place to another on a DNA molecule.
What type of test do you do if you want to determine a sensitivity test (which antibiotic would work best for a specific infection)?
Kirby Bauer (disk diffusion) test.
Amino acids from protein degradation can be used directly in which metabolic process(es)? -glycolysis -Krebs cycle -oxidative phosphorylation -Krebs cycle AND glycolysis -fermentation
Krebs cycle AND glycolysis
In Prokaryotes - Lac operon like a thermostat
Lac operon is like a thermostat in which the substrate (molecule being broken down), lactose, induces production of the enzyme that will break it down, lac. Thermostats turn on when the temp is low (for example), and will turn off when the temp is too hi. The lac operon does the same thing, in low concentrations of lactose, it's off, and in high concentrations, its on. Since the product is glucose, and high glucose levels also dampen the production of Lac genes, It's an example of feedback inhibition this is an example of a "inducible" gene
Phase in a growth curve in which organisms are adjusting to their environment.
Lag phase
a
Ligase plays a major role in a. lagging strand replication b. mRNA processing in eukaryotese c. polypeptide synthesis by ribosomes d. RNA transcription
The redox reactions of photosynthesis are classified as what other types of reactions? (There are two).
Light dependent reactions and light independent reactions
in the 5' to 3' direction
Like DNA Polymerase, RNA Polymerase joins Nucleotides in what direction?
Many disinfecting agents, like Lysol, are phenol derivatives. Who discovered phenol and why don't we use it anymore?
Lister, used it in operating rooms to improve patients chance of survival. Don't use anymore because it is carcinogenic.
During which phase of bacterial growth would you see cell dividing most rapidly?
Log phase
Heavy Metals
Low-Level Bacteristatic and Fungistatic Agents
Enzymes can be classified as hydrolases,isomerases,ligases (polymerase),____________,oxidoreductases, or __________,reflecting their mode of action.
Lyases;transferases
Removal of water from a frozen culture or other substance by means of vacuum pressure, used for the long term preservation of cells and food.
Lyophilization
__________ agar distinguishes lactose-fermenters from non-lactose-fermenters.
MacConkey
Which of the following is both a selective and a differential medium? -nutrient broth -blood agar -MacConkey agar -Sabouraud dextrose agar
MacConkey agar
deoxyribose sugar
Makes up the sides of the DNA 'ladder', alternating with phosphates.
The four main types of RNA
Making new DNA: 1. RNA primer -- short segment of RNA used to initiate synthesis of a new strand of DNA during replication Making new proteins using DNA as source of information: 2. Messenger RNA (mRNA) carries the DNA instructions for building the protein, 3. Transfer RNA (tRNA) carries the appropriate amino acid to the ribosome, 4. Ribosomal RNA (rRNA) is the major component of a ribosome, the structure that reads codons on the mRNA and assembles amino acids into polypeptides.
Ex of aerotoleran, microaerophilic, or obligate anaerobes?
Many prokaryotes and a few protozoa
Microorganism requiring temperatures ranging from 20 degrees celcius to about 40 degrees celcius.
Mesophile
__________ prefer growth temperatures in the range of 20°C to 40°C.
Mesophiles
what are the 3 indirect methods of quantifying bacterial numbers?
Metabolic activity Dry weight Turbidity
streak plate
Method of culturing microorganisms in which a sterile inoculating loop is used to spread an inocolum across the surface of the solid medium in Petri dishes
Pour plate
Method of culturing microorganisms in which colony-forming units are separated from one another using a series of dilutions
Positive Selection
Method to recognize Mutants by elminating Wild Type Phenotypes
Negative (Indirect) Selection
Method to recognize Mutants by isolating Auxotrophs (organisms with nutritional requirements different from those of its Wild Type Phenotype) by comparing colonies grown on media with and without the Auxotroph's required nutrients
How does DNA methylation play a role in protection against viral infection?
Methylation at specific sites in a nucleotide sequence enables cells to distinguish their DNA from viral DNA which lacks methylation. The cells can then selectively degrade the non-methylated DNA.
Although the active sites of chlorophylls and cytochromes are structurally similar, they differ in that chlorophylls use ________ rather than the ________ found in cytochromes.
Mg2+; Fe2+
Using thioglycollate growth medium, how you would know an organism is microaerophilic aerobe?
Microaerophiles would be found slightly below the surface, but neither directly at the surface nor in the depths of the tube
obligate halophiles
Microbes that are adapted to growth under high osmotic pressure
Chemoautrotoph
Microogranism that uses carbon dioxide as a carbon source and catabolizes organic molecules for energy
Acidophiles
Microorganism requiring acidic pH
alkinophiles
Microorganism requiring alkaline pH environments
Psychrophiles
Microorganism requiring cold temperatures (below 20 degree C)
neutrophiles
Microorganism requiring neutral pH
Termophile
Microorganism requiring temperatures above 45 degree C
Hyperthermophile
Microorganism requiring temperatures above 80 degree C
Mesophiles
Microorganism requiring temperatures ranging from 20 degree C to about 40 degree C
Photoheterotroph
Microorganism that requires light energy and gains nutrients via catabolism of organic compounds
obligate aerobes
Microorganism that requires oxygen as the final electron acceptor of the electron transport chain
Chemoheterotrophs
Microorganism that uses organic compounds for both energy and carbon
photoautrotophs
Microorganism which requires light energy and uses carbon dioxide as a carbon source
Streptococcus pneumoniae
Most common pathogenic source of pneumonia in elders has thick capsule
By what factor do mutagens increase the rate of mutations?
Mutagens increase the mutation rate by a factor of 10 to 1000 times
deleterious
Mutation is usually ____________.
frameshift
Mutation that involves the insertion or deletion of a nucleotide in the DNA sequence
Which compound provides the electrons at the start of the electron transport system in? NADH O2 H2O ATP
NADH
Which of the following is NOT a possible product of fermentation? -acetone and alcohol -2,3-butanediol -lactic acid -NADH
NADH
Which of the following is an electron carrier used in the Krebs cycle? (possibly more than one answer) -GTP -NADH -FADH2 -all of the above -none of the above
NADH FADH2
Which of the following are products of glycolysis? (possibly more than one answer) -ATP -pyruvic acid -NADH -NAD+ -glucose
NADH pyruvic acid ATP
What is the function of NADH in fermentation? -NADH provides the electrons to reduce pyruvic acid to either an organic acid or ethanol. -NADH takes electrons to the electron transport chain. -NADH is reduced so it can return to glycolysis to pick up more electrons. -NADH is converted to organic acids like lactic acid.
NADH provides the electrons to reduce pyruvic acid to either an organic acid or ethanol.
What transports electrons from the light reactions to the Calvin cycle? -NADH -An electron transport chain -NADPH -Chlorophyll -FADH2
NADPH
Which of the following is not involved in cyclic photophosphorylation? cytochromes chlorophyll NADPH water
NADPH
Three important electron carrier molecules are _______,_____,_____.
Nad+,Nadp+,fad
Initiation, Elongation, Termination
Name the steps of transcription in order
Streptococcus, Staphylococcus, Pseudomonas, Neisseria, and Bacillus
Natural competency is seen only in a few bacteria. What 5 species of bacteria have natural competency?
Which of the following is a true statement regarding the HIV medication nevirapine? -Nevirapine is the substrate of reverse transcriptase. -Nevirapine binds to a location other than the active site. -Nevirapine binds to the active site of reverse transcriptase. -Nevirapine binds to the substrate of reverse transcriptase.
Nevirapine binds to a location other than the active site.
The conversion of atmospheric nitrogen to ammonia.
Nitrogen fixation
Which of the following statements concerning nitrogen is FALSE? -Nitrogen is rarely a growth-limiting nutrient. -All cells can recycle nitrogen from their nitrogen-containing molecules. -Only a few types of bacteria can engage in nitrogen fixation. -Nitrogen is essential for the production of amino acids and nucleotide bases
Nitrogen is rarely a growth-limiting nutrient
Thymine
Nitrogenous base that is only in DNA
Uracil
Nitrogenous base that is only in RNA
Can activation energy ever be totally eliminated?
No
Is production of NADPH associated with the process of glycolysis?
No
Catalysts increase rates of chemical reactions. The catalysts is changes in the process. Is this change permanent?
No. Catalysts are not permanently changed in the process of increasing rates of chemical reactions.
In ___________ ______________ , photosystem2 works with photo system 1 and the electrons are used to reduce NADP+ to NADpH
Noncyclic photophosphorylation
Remember - building blocks Nucleic acids = amino acids =
Nucleic acids = nucleotides (DNA, RNA) amino acids = polypeptides (proteins)
Chemical Mutagens
Nucleotide Analogs, Nucleotide-Altering Chemicals, and Frameshift Mutagens
Promoter
Nucleotide sequence near the beginning of the gene that starts Transcription
What are nucleotides composed of?
Nucleotides are composed of a phosphate group and a nucleoside.
d
Nucleotides used in the replication of DNA a. carry energy b. are found in four forms, each with a deoxyribose sugar, a phosphate, and a base c. are present in cells as triphosphate nucleotides d. all of the above
Transcription Factors
Numerous ___________ _________ aid in binding RNA Polymerase to Promoter sequences IN EUKARYOTES. (as opposed to just the Sigma Factors that are used in Bacterial Transcription)
what is the difference between obligate acidopholes and acid-tolerant microbes?
Obligate acidophiles require an acidic environment and die if the pH approaches to 7.0, acid tolerant microbes merely survive in acid without preferring it
Using thioglycollate growth medium, how you would know an organism is obligate aerobes?
Obligate aerobes cannot survive below the depth to which oxygen penetrates the medium, so they are at the top of the tube
Microorganism that cannot tolerate oxygen AnD uses a final electron acceptor other than oxygen.
Obligate anaerobe
_________ __________ are killed by the toxic forms of oxygen, including superoxide radical.
Obligate anaerobes
Using thioglycollate growth medium, how you would know an organism is obligate anaerobe?
Obligate anaerobes cannot tolerate any oxygen, so they are found at the bottom of the tube
RNA Primer
One RNA Polymerase transcribes ___ ______.
E site
One of a ribosome's three binding sites for tRNA during translation. The E site is the place where discharged tRNAs leave the ribosome. E = exit
Splicing
One type of eukaryotic mRNA processing in which introns are removed from the primary transcript and exons are ligated together. SPlicing of transcripts can be different in different tissues.
5' Guanine Cap
One way in which Eukaryotic Translation differs from Prokaryotic Translation- Initiation occurs when a small ribosomal subunit binds to the ___ ________ ____ of mRNA instead of a specific Nucleotide sequence
What is specialized transduction?
Only certain donor DNA sequences are transferred
How microorganism are sensitive to pH?
Organisms sensitive to changes in acidity because it affects proteins and nucleic acids. (hydrogen and hydroxyl ions interfere with hydrogen bonding)
Thermophiles
Organisms that are found in conditions hot, 45-100 degrees celcius; that most organisms cannot tolerate them.
Microorganism that acquires electrns from organic sources.
Organotroph
_________ _________ is created as cells rapidly lose or gain water when they are in hypertonic or hypotonic solutions.
Osmotic pressure
Proteases secreted by microorganisms digest proteins (inside/outside) the microbes cell walls. The resulting _____________ __________ are moved into the cell and used in anabolism, or deaminated and catabolized for energy.
Outside
_________ ______ is the last compound formed in the Krebs cycle
Oxaloacetic acid
Oxidation and reduction reactions always occur in pairs called ________-__________(__________) reactions.
Oxidation-reduction(redox)
Ozone
Oxidizing agent for the treatment of drinking water
Hydrogen Peroxide
Oxidizing agent that can disinfect and sterilize surfaces of objects
Peroxides, Ozone, and Peracetic Acid
Oxidizing agents that kill by oxidation of microbial Enzymes
Which of the following statements regarding cell metabolism is true? -Water from photosynthesis can be used in oxidative phosphorylation. -Oxygen produce from photosynthesis can be used in oxidative phosphorylation. -Photosynthesis and oxidative phosphorylation have no interaction. -Carbon dioxide from photosynthesis is used in the Krebs cycle.
Oxygen produce from photosynthesis can be used in oxidative phosphorylation.
Sulfanilamide mimics the three-dimensional shape of _______, thereby competitively inhibiting the activity of the enzyme that helps convert PABA into ______ ________
PABA;folic acid.
what are some of the methods used in medical diagnoses?
PCR, fluorescent genetic probes, and DNA microarrays (genetic sequencing)
Inverted Repeats
Palindromic sequences such as GAATTC and CTTAAG)
where insulin is produced within our bodies?
Pancreas
mRNA, tRNA, Ribosomes, and rRNA
Participants in Translation
what is an example of using mutagens?
Penicillium that produced Penicillin
Name two alternative means for the catabolism of glucose, that yield fewer molecules than glycolysis?
Pentose phosphate ; Entner-Doudoroff
Oxidizing Agents
Peroxides, Ozone, and Peracetic Acid
Dish filled with solid medium used in culturing microorganisms.
Petri plate
__________ is a cellular process that attaches a phosphate group to adenosine diphosphate using a high-energy bond. Catabolism Metabolism Beta-oxidation Phosphorylation
Phosphorylation
_________is the addition of phosphate to a molecule.
Phosphorylation
- is a genus that switches the flow of electrons from NADH to a system that generates light.
Photobacterium
____________is the phosphorylation of ADP with inorganic phosphate using energy from light.
Photophosphorylation
-networks of lght-absorbing chlorophyll molecules and other pigments held within a protein matrix on membranes called thylakoids.
Photosystems
Enveloped viruses, Gram-positive bacteria, Nonenveloped viruses, Fungi, Gram-negative bacteria
Place these types of microorganisms in order from most susceptible to most resistant: Fungi, Gram-positive bacteria, enveloped viruses, Gram-negative bacteria, and nonenveloped viruses
Gram-negative bacteria, Active stage protozoa (trophozoites), Cysts of protozoa, Mycobacteria, Bacterial endospores
Place these types of microorganisms in order from most susceptible to most resistant: Mycobacteria, Active stage protozoa (trophozoites), Bacterial endospores, Gram-negative bacteria, and Cysts of Protozoa
What is unique about methylation of nucleotides in eukaryotes?
Plant and animal cells methylate cytosine bases exclusively.
What are plasmids?
Plasmids are extra-chromsomal small DNA molecules that replicate independently and are not needed for regular cell metabolism or functions.
Nucleic Acids
Polymers of Nucleotides
Methods to recognize Mutants
Positive Selection and Negative (Indirect) Selection
What is positive selection?
Positive selection involves selecting a mutant by eliminating wild-type phenotypes
Method of culturing microorganisms in which colony-forming units are separating from me another using a series of dilutions.
Pour-plate
Examples of sterilization
Preparation of microbial culture media and canned food
Genetic screening
Procedure by which laboratory tests are used to screen patient and fetal DNA for mutant genes
Prokaryotic cells are ________. (Haploid/Diploid)
Prokaryotic cells are haploid.
___________ are usually secreted outside the cytoplasmic membrane to break down proteins, which are too large to enter the cell through the cytoplasmic membrane.
Proteases
A proton gradient has potential energy known as a ____________ _______________ ____________.
Proton motive force
Microorganism requiring cold temperatures (below 20 degrees Celsius)
Psychrophile
Most drug resistant bacteria isolated from patients contain drug-resistance genes located on ______
R plasmids
80S Ribosomes
RIbosomes found in cytosol and attached to the membrane of the Endoplasmic Reticulum within the Eukaryotic Cell
RNA is different than DNA
RNA is the single-stranded molecule similar to DNA.(mRNA=messenger RNA. tRNA=transfer RNA). DNA is the double-stranded molecule that contains the genetic code. DNA cannot leave the nucleus. RNA has ribose, DNA has deoxyribose
Short Interference RNA
RNA molecule complementary to a portion of mRNA, tRNA, or a Gene that it binds to and renders inactive
Ribozymes
RNA molecules that act as enzymes and are in the nucleus and remove Introns and splice Exons together forming functional mRNA that leaves the nucleus
initiation
RNA polymerase binds to specific nucleotide sequences called promoters located near the beginning of the gene. Primase transcribes the RNA primer and RNA polymerase transcribes mRNA, rRNA and tRNA
Describe the initiation process of transcription.
RNA polymerase binds to specific nucleotide sequences called promoters located near the beginning of the gene. Primase transcribes the RNA primer and RNA polymerase transcribes mRNA, rRNA and tRNA.
How does a cell use sigma factors to exert control over transcription?
RNA polymerases using different sigma factors do not adhere equally strongly to all promoters.
What are RNA primers used for?
RNA primers are used for DNA polymerase to use during DNA replication
Where does RNA transcription begin?
RNA transcription begins at a spot 10 nucleotides away from the promoter.
effects on cellular chemicals
Radiation is Ionizing or Nonionizing according to their _____ __ ________ ________.
A __________ ______________chlorophyll is a special chlorophyll molecule in a photo system in which electrons are excited by light energy and passed to an acceptor molecule of an electron transport chain.
Reaction center
Recombinant approach solutions the problem of_when using vaccines
Recombinant approach, solutions the problem of injecting whole organism that could sick us, by producing only a part of the vaccine so less likely to make you sick
Antisepsis
Reduction in the number of micoorganisms and viruses, partucularly potential pathogens, on living tissue
Antisepsis
Reduction in the number of microorganisms and viruses, particularly potential pathogens, on living tissue
_________________reactions are those in which electrons are added. The molecule that donates the electrons in ____________.
Reduction;Oxidized
Aseptic
Refers to an environment or procedure free of pathogenic contaminants
halts growth
Refrigeration _____ ______ of most pathogens.
nucleoid
Region of prokaryotic cells where DNA is located
operator
Regulatory element in an operon where repressor protein binds to stop transcription.
antagonistic relationship
Relationship in which one organism harms or even kills another organism
Degerming
Removal of microbes by mechanical means
Degerming
Removal of microbes by mechanical means (scrubbing is important)
Sanitization
Removal of pathogens from objecs to meet public health standards
Sanitization
Removal of pathogens from objects to meet public health standards
In the synthesis of the lagging strand, what is the function of DNA polymerase I?
Replaces RNA primers with DNA and proofreads the Okazaki fragments.
What are replicating transposons?
Replicating transposons may replicate while moving, resulting in more transposons in the cell.
b
Repressible operons are important in regulating prokaryotic a. DNA replication b. RNA transcription c. rRNA processing d. sugar catabolism
What are resistance plasmids?
Resistance plasmids carry gens for resistance to one or more antimicrobial drugs.
In oxidative phosphorylation, energy from redox reactions of _______________is used to attach inorganic phosphate (PO4 3-) to ADP
Respiration
rRNA
Ribosomal RNA
P site
Ribosomal binding site that holds tRNA and the growing Polypeptide attached to it
A site
Ribosomal binding site that holds tRNA bringing in an Amino Acid
rRNA and numerous polypeptides
Ribosomes are composed of what?
Anaerobes use inorganic molecules such as (No3-,_____,and CO3 2-), or rarely an externally acquired organic molecule as the final electron acceptor in anaerobic respiration.
SO4 2-
How does SOS response work?
SOS response involves a variety of processes including the production of new DNA polymerases capable of copying less than perfect DNA.
Describe the Ames Test for Identifying Mutagens
Salmonella possessing a point mutation that prevents the synthesis of histidine. If the substance is mutagenic, it is likely that the salmonella will produce histidine.
How do scientists distinguish mutants from wild types?
Scientists distinguish mutants from wild-types by observing or testing for altered phenotypes.
Culturing medium containing substances that either favor the growth of particular microorganisms or inhibit the growth of unwanted ones.
Selective medium
What is selective toxicity and who was Paul Ehrlich?
Selective toxicity: the ability to inhibit or kill pathogenic microorganism without adversely affecting the host. Paul Ehrlich developed this concept, searched for the "magic bullet" that would kill only pathogens. Discovered Salvarsan, an arsenic containing compound that killed the syphilis microbe
Of the following ways in which cells regulate metabolism, what is the way that is seen ONLy in eukaryotes? Control of gene expression, metabolic expression,synthesizing or degrading proteins and enzymes, sequestering reactions in membrane-bound organelles, and feedback inhibition.
Sequestering reactions in membrane-bound organelles
Okazaki fragments
Short fragments of DNA that are a result of the synthesis of the lagging strand during DNA replication.
Insertion Sequences
Simplest transposable elements, exist only in bacteria, contains a single gene which codes for transposase, an enzyme that catalyses movement of the insertion sequence from one site to another within the genome
When excess Tryptophan is present
Since enzymes for making Tryptophan are not made, Tryptophan acts as a Corepressor of its own synthesis
Which of the following characteristics is a hallmark of bacterial growth? After several rounds of division, the genetic diversity of the bacterial population will be very diverse. Since the number of bacterial cells double after each round of replication, the number of cells rapidly increases. All daughter cells produced will be smaller than the parent. Bacterial growth is fast because all bacterial cells undergo mitosis.
Since the number of bacterial cells double after ach round of replication,the number of cells rapidly increases.
Test tube containing agar media that solidified while the tube was resting at an angle.
Slant tube
how can you determine the amount of DNA in gel electrophoresis technique?
Smaller and thinner lines has less amount of DNA than big square-shaped lines
In eukaryotic transcription, what is splicing?
Splicing is removing all the introns to make a functional mRNA containing only coding regions called exons
What are spliciosomes?
Spliciosomes are RNA molecules attached to polypeptides used to splice the pre mRNA
Which organism was the first to develop antibiotic resistance?
Staph aureus
AUG
Start Codon; also codes for and Amino Acid; Methionine (in Eukaryotes and Archaea) and N-formylmethionine (in Bacteria)
During which phase of growth would you find the highest number of total cells, both living and dead?
Stationary phase
Free of microbial contamination.
Sterile
UAA, UAG, and UGA
Stop codons
In Griffith's experiments, which strain of cells were deadly before being heated?
Strain S was deadly because they had protective capsules.
What are two common isolation techniques?
Streak plates Pour plates
Components of an Operon
Structural Genes, Promoter, and Operator
How does concentration of the substrate affect the ability of a noncompetitive inhibitor to disrupt enzyme activity? -High concentrations of substrate can overcome the presence of low amounts of inhibitor. -Low concentrations of substrate can overcome the presence of low amounts of inhibitor. -The presence of substrate in either high or low concentrations will overcome low amounts of inhibitor. -Substrate concentration has no effect on the inhibitor, since they are not competing for the active site.
Substrate concentration has no effect on the inhibitor, since they are not competing for the active site.
What three types of phosphorylation for ATP?
Substrate level phosphorylation,oxidative phosphorylation, and photophosphorylation
What type of phosphorylation involves the transfer of phosphate from a phosphorylated organic compound to ADP?
Substrate-level phosphorylation
-the molecules for which enzymes (organic catalysts) act upon.
Substrates
-stasis -static
Suffixes indicating inhibition, but no complete destruction, of a type of microbe
Why are supercoils formed during DNA replication?
Supercoils are formed during DNA replication because the unzipping and unwinding action of helicase introduces coils ahead of the replication fork.
Synthesis of the Lagging Strand
Synthesis which is discontinuous, and occurs only in short fragments, forming Okazaki Fragments
Antibiotics may be selectively inactivated by chemical modification or cleavage. T/F
T
True or False:Enzymatic reactions reach a saturation point when the active sites of all enzymes present are occupied by substrate molecules.
TRue!!! This phenomenon is a limiting factor for all enzymatic reactions.
Southern blotting
Technique used in recombinant DNA technology that allows researchers to stabilize specific DNA sequences from an electrosphoresis gel and then localize them using DNA dyes or probes
optimum growth temperature
Temperature at which a microorganism's metabolic activities produce the highest growth rate
Ames test
Test in which special strains of bacteria are used to evaluate the potential of chemicals to cause cancer.
At which site of the DNA strand is the phosphate found.
The 5 prime end always has phosphate attached
How do we know things listed in the book can cause mutations
The AMES test, developed by Bruce Ames. He came up with this test because things that cause mutations very oftern cause carcinogens. Everything that goes into us or on us goes through the AMES test.
What does the AUA codon do?
The AUA codon codes for isoleucine and codes for methionine in mitochondria.
What does the AUG codon do?
The AUG codon is the STOP codon. It has an alternative use of coding for glutamine in some protozoa and pyrrolysine, a 22nd amino acid, in some prokaryotes.
a
The Ames test a. uses auxotrophs and liver extract to reveal mutagens b. is time intensive and costly c. involves the isolation of a mutant by eliminating wild-type phenotypes with specific media d. proves that suspected chemicals are carcinogenic
Which happens first in bacterial cell division? -The DNA is replicated. -Chromosomes move into two separate regions of the cell. -The cell elongates. -The mitotic spindle forms
The DNA is replicated.
When Lactose is not present
The Repressor, which is continually synthesized under the direction of the Regulatory Gene, binds to the Operator and prevents RNA Polymerase from transcribing Structural Genes
When Tryptophan is not present
The Repressor, which is continually synthesized, is inactive and cannot bind to the Operator, so RNA Polymerase binds to the Promoter and Structural Genes are transcribed
two
The Simplest Transposons are INSERTION sequences which have no more than ___ Inverted Repeats and the gene for Transposase
effectiveness and safety of Antimicrobial drugs
The Structural differences between Prokaryotic and Eukaryotic Ribosomes are important in the _____________ ___ ________ __ ______________ _____.
What does the UGA codon do?
The UGA codon is STOP codon and also codes for selenocystein. It has an alternative use for coding for tryptophan in mitochondria and mycoplasms.
a
The addition of ---CH₃ to a cytosine nucleotide after DNA replication is called a. methylation b. restriction c. transcription d. transversion
How are the bases of nucleotides attached to each other?
The bases of nucleotides (A,T,G,C) are hydrogen bonded to each other in specific ways called complementary base pairs.
Describe the process of capping in eukaryotic transcription.
The cell adds a modified guanine nucleotide to the 5' end of the RNA molecule is about 30 nucleotides long.
Why do cells that are placed in fresh media not immediately enter logarithmic phase of growth?
The cells need to switch their metabolic state from a dormant one to an actively growing one.
state the central dogma of genetics and explain the roles of RNA and DNA in polypeptide synthesis
The central dogma of molecular biology doctrine that genetic instructions in DNA are copied by RNA, which carries them to a ribosome where they are used to synthesize a protein. (DNA→RNA → protein)
nitrogen base
The chemicals that make up the rungs of the DNA ladder. A-T and C-G match.
What are the components of DNA and its three-dimensional structure?
The components of a DNA molecule are nucleotides. These are composed of a deoxyribose sugar bonded to a phosphate and a nucleotide base (adenine, thymine, cytosine, or guanine). The three-dimensional structure of DNA is a double helix, which resembles a twisted ladder.
temperature, length of exposure, the amount of organic matter, pH, concentration, and the age of the chemical
The effect of chemical methods of microbial growth varies with what?
Which of these statements is NOT true of the electron transport chain? -In bacteria, the electron transport chain is located on the cytoplasmic membrane. -In aerobic organisms, oxygen is the final electron acceptor in the electron transport chain. -The electron transport chain in eukaryotes is located on the outer mitochondrial membrane. -The electron transport chain creates a proton motive force that drives ATP synthesis.
The electron transport chain in eukaryotes is located on the outer mitochondrial membrane.
Which statement describes the electron transport chain? -Electron transport chain converts pyruvic acid to acetyl CoA. -This process produces some ATP and carbon dioxide. -The electron transport chain splits glucose in half and produces 2 ATPs for each molecule of glucose. -The electron transport chain uses energy captured from electrons flowing to oxygen to produce most of the ATPs in cellular respiration. -The electron transport chain joins 2 pyruvic acid molecules into a molecule of glucose.
The electron transport chain uses energy captured from electrons flowing to oxygen to produce most of the ATPs in cellular respiration. - In the electron transport chain, electrons move from one electron carrier to another, eventually reaching oxygen. The released energy is used to make many molecules of ATP.
Which of the following statements is the basis of the induced-fit model? -Products dissociate rapidly from the enzyme. -Each enzyme can react with many different substrates. -Enzymes are left unchanged following the interaction with their substrates. -The enzyme and substrate bind at the active site to form a perfect fit known as the enzyme-substrate complex
The enzyme and substrate bind at the active site to form a perfect fit known as the enzyme-substrate complex.
Which of the following may happen after a substrate binds at the active site? -The enzyme may slow down the chemical reaction, decreasing the time needed for the reactants to produce the products. -The enzyme may convert the substrate to reactants. -The enzyme may change shape and the amino acids found in the active site may donate or receive electrons.
The enzyme may change shape and the amino acids found in the active site may donate or receive electrons.
Which of the following is NOT a characteristic of a complex medium? -Complex media are especially helpful in growing organisms whose exact nutritional requirements are unknown. -Complex media are used for routine growth of many different species of bacteria. -The exact chemical composition is known. -Nutrient broth and trypticase soy agar are examples of complex media.
The exact chemical composition is known.
Homologous Sequences
The exchange of Nucleotide Sequences is often mediated by DNA segments composed of what?
What is the relationship between sigma factor strength and likelihood of gene transcription?
The greater the attraction between a particular sigma factor and a promoter, the more likely that a particular gene will be transcribed.
What did Griffiths experiment conclude?
The harmless, unencapsulated R strain has been transformed into deadly S strain when mixed together.
what is the important end result of recombinant DNA technology method?
The important end result is not DNA by itself but the protein to change phenotype of organism
synergistic relationships
The individual members of an association cooperate such that each receives benefits that exceeds those that would result if each lived by itself, even though each member could live separately
The term "competitive" in competitive inhibitors refers to what? -The inhibitor and the substrate are competing for reactants. -The inhibitor is competing with the substrate for the production to see which makes the most products. -The inhibitor is competing with the enzyme for the substrate. -The inhibitor and the substrate are competing for the active site of the enzyme
The inhibitor and the substrate are competing for the active site of the enzyme.
The term "competitive" in competitive inhibitors refers to what? -The inhibitor is competing with the substrate for the production to see which makes the most products. -The inhibitor and the substrate are competing for reactants. -The inhibitor is competing with the enzyme for the substrate. -The inhibitor and the substrate are competing for the active site of the enzyme
The inhibitor and the substrate are competing for the active site of the enzyme.
What would happen if the concentration of substrate is low? -The inhibitor will destroy the substrate. -The inhibitor will successfully compete with the substrate for the active site, speeding up catalysis. -The inhibitor will successfully compete with the substrate for the active site, slowing catalysis. -The inhibitor will destroy the enzymes.
The inhibitor will successfully compete with the substrate for the active site, slowing catalysis.
What would happen if the concentration of substrate is low? -The inhibitor will successfully compete with the substrate for the active site, speeding up catalysis. -The inhibitor will destroy the substrate. -The inhibitor will successfully compete with the substrate for the active site, slowing catalysis. -The inhibitor will destroy the enzymes.
The inhibitor will successfully compete with the substrate for the active site, slowing catalysis.
How does the action of DNA polymerase III differ in the synthesis of the lagging strand as compared to the leading strand?
The lagging strand is synthesized discontinuously in segments called Okazaki fragments.
In eukaryotic DNA replication, why are there so many origins per molecule?
The large size of eukaryotic chromosomes necessitates thousands of origins per molecule, each generating two replication forks.
How the sterile loop is used in the streak plate process?
The loop is used to lightly streak a set pattern that gradually dilutes the sample to a point that CFUs are isolated from one another
What is the nuclear envelope?
The nuclear envelope is double-membrane layer that surrounds the nucleus of eukaryotic cells.
Why is the pause in transcription during self-termination important?
The pause in transcription provides enough time for the RNA molecule to form hydrogen bonds between its own symmetrical sequences, forming a hairpin loop structure that puts tension on the union of RNA polymerase and the DNA.
What is the outcome if the concentration of the substrate is much higher than that of the inhibitor? -The reaction will be carried out as usual. -The substrate will destroy the inhibitor. -The enzyme will stop functioning. -The reaction will slow down catalysis of the products.
The reaction will be carried out as usual.
What is the outcome if the concentration of the substrate is much higher than that of the inhibitor? -The substrate will destroy the inhibitor. -The enzyme will stop functioning. -The reaction will slow down catalysis of the products. -The reaction will be carried out as usual.
The reaction will be carried out as usual.
How does mismatch repair work?
The repair enzyme recognizes mismatch, DNA polymerase III comes in and repairs the gap- recognizes unmethalated sequences before they become methylated
Proteases secreted by microorganisms digest proteins outside the microbes cell walls. What could happen to the resulting amino acids?
The resulting amino acids are moved into the cell and used in anabolism, or deaminated and catabolized for energy.
how genome mapping has been speeded up?
The technique has been speeded up by an automated machine that distinguishes among fluorescent dyes attached to each type of nucleotide base.
what are the areas where DNA fingerprinting is used?
The technique is used in paternity investigations, crime scene forensics (ID badly damaged human), diagnostic microbiology (ID pathogen), and epidemiology.
In self-termination, why does RNA polymerase slow down during transcription of the Guanine-Cytosine portion?
The three hydrogen bonds each between guanine and cytosine make unwinding the DNA helix more difficult.
b
The trp operon is repressible. This means it is usually _______________ and is directly controlled by ______________ a. active / an inducer b. active / a repressor c. inactive / an inducer d. inactive / a repressor
Gene therapy
The use of recombinant DNA technology to insert a missing gene or repair a defective gene in human cells
There are three stages involved in translation:
There are three stages involved in translation: 1.Initiation 2.Elongation 3.Termination
Nucleotide-Altering Chemicals
These result in Base-Pair Substitution Mutations and Missense Mutations
Which of the following represent a true statement about the resulting new daughter cells? They are unable to divide. They are genetically identical to the parent. Four new daughter cells result from one parental cell. They share characteristics of both parental cells.
They are genetically identical to the parent
What is relevant about sulfanilamide and PABA? (one or both answers may be correct) -They have a similar chemical structure. -They will bind to the same active site.
They have a similar chemical structure and they will bind to the same active site.
How scientists combine fragments of DNA formed by restriction enzymes?
They then combine these bits of DNA with ligase to form recombinant DNA molecules.
Photo systems are networks of light-absorbing chlorophyll molecules and other pigments held within a protein matrix on membranes called ______________.
Thylakoids
The active site of a chlorophyll molecule is structurally most similar to which of the following? -folic acid -RuBP -thylakoids -cytochromes
Thylakoids
what advantage gives genetic screening to patients, especially parents?
To allow parents, before having kids, what mutations they carry if they wan to have kids
What is the ultimate function of an organisms metabolism?
To reproduce the organism
Griffiths Experiment
Took mice and infected them with streptococcus pneumonia, the living cells took up fragments of the dead cells and were able to create a capsule.
What is the function of topisomerase?
Topoisomerases remove supercoils in DNA molecule
Element required in very small amounts for microbial metabolism.
Trace element
-occurs when an amine group is transferred from one amino acid to another.
Transamination
____________ is the transfer of an amine group from amino acid to amino acid.
Transamination
Mitochondria and Chloroplasts
Transcription in Eukaryotes also occurs in _____________ ___ __________.
What is transcription?
Transcription is the process in which DNA is copied as RNA.
transcription
Transcription is the process in which DNA is copied as RNA.
How does self termination work?
Transcription of DNA terminator sequences causes the RNA to fold, loosening the grip of polymerase on DNA.
b
Transcription produces a. DNA molecules b. RNA molecules c. polypeptides d. palindromes
What is generalized transduction?
Transducing phage carries random DNA segment from donor to recipient
_______________ RNA carries amino acids
Transfer
Why is transformation significant?
Transformation is significant because it is one of conclusive pieces of proof that DNA is genetic material
What is transformation?
Transformation is when a recipient cell takes up DNA from the environment.
What is translation?
Translation is the process in which polypeptides are synthesized from RNA
translation
Translation is the process in which polypeptides are synthesized from RNA
Transposons all contain _______ sequences at each end.
Transposons all contain palindromomic sequences at each end.
Palindromic Sequences
Transposons all contain what at each end?
What is the function of triphosphate deoxyribonucleotides?
Triphosphate deoxyribonucleotides provide monomers and energy for anabolic polymerization.
Describe the process of translation.
Triphosphate ribonucleotides align with their DNA complements and RNA polymerase links them together, synthesizing RNA. No primer is needed. The triphosphate ribonucleotides also provide the energy required for RNA synthesis.
The activation energy of a chemical reaction is lower in the presence of an enzyme. True or False
True
When excess Tryptophan is present
Tryptophan becomes a Corepressor- a molecule that attaches to a Repressor, enabling it to bind to the Operator; This prevents RNA Polymerase from transcribing Structural Genes, so no enzyme for synthesizing Tryptophan are made
Which diabetes is found in people that born with it?
Type I
what are the names of the two types of diabetes?
Type I diabetes Type II diabetes
How does UV light present a problem during replication?
UV light causes pyrimidine (thymine and cytosine) dimer. The resulting distortion of the sugar phosphate backbone prevents proper replication and transcription
What is used to disinfect the air in A/C ducts and surgery rooms?
UV radiation
Nonionizing Radiation
UV rays; forms Pyrimidine Dimers (T-T, C-C, or T-C bond with each other) which interfere with DNA replication
__________ are electron transport molecules that are lipid-soluble, nonprotein carriers.
Ubiquinones
what case of gene therapy resulted in the death of the patient?
University of Pennsylvania Study 18yr old died from clinic trial
How can I recognize the difference between the bacteria that got the plasmid and the bacteria that did not get it in transformation?
Use ampicillin plate to selectively cultivate the bacteria that have the plasmid, which is resistant to ampicillin (ampicillin resistant) because of plasmid (Contain recognizable genetic marker)
Pasteurization
Use of heat to destroy pathogens and reduce the number of spoilage microorganisms in food and beverages
Pasteurization
Use of heat to destroy pathogens and reduce the number of spoilage microorganisms in foods and beverages
How can we use the Dogma of genetics in genetic engineering?
Use the Dogma of genetic, knowing how bacteria work, how diseases work in humans, get products that we cannot make by our own and start to use this information to make bacteria to make this products
how the information about microorganisms can benefit us?
Use what we know about microorganisms and the genetics to change living things to produce things that are useful for us
How does filtration work for sterilization?
Used on liquids and gases that are heat sensitive. Fluid passes through the pores in the filter and anything larger than the pores is trapped in the filter.
Moist Heat
Used to disinfect, sanitize, and sterilize. Kills by denaturing proteins and destroying cytoplasmic membranes, and is more effective than dry heat.
Membrane Filtration
Uses a milpore filter takes at least 24 hours but filters live cells
What are some differences between eukaryotic DNA replication from bacterial DNA replication?
Uses four DNA polymerases Thousands of replication origins Shorter Okazaki fragments- 100-400 nucleotides long Plant and animal cells methylate only cytosine bases
What size filter should you use? What size filter should you use if your are trying to filter out Mycoplasma?
Usually 0.45 microns Mycoplasma: 0.22 microns
61
Usually, __ Codons specify Amino Acids, and 3 are Stop Codons
Differential media
Utilizes differences in growth or colony characteristics to distinguish between species.
what are the 5 direct methods of quantifying bacterial numbers? (state which require incubation and which not)
Viable plate counts (require incubation) Membrane filtration (require incubation) Microscopic counts (Do not require incubation) Electronic counters (do not require incubation) Most probable number (require incubation)
What are virulence plasmids?
Virulence plasmids carry instructions for structures, enzymes, or toxins that enable a bacterium to become pathogenic.
Within vectors, who can carry larger genes?
Viruses and transposons can carry larger genes than plasmids
Temperature
Warm disinfectants work better than cooll ones because the chemicals react at a faster rate.
Lower
Water boils at _________ temperatures at higher elevations.
Chemicals, Radiation, and Heat
What 3 things can alter or destroy Nucleic Acids?
Ethylene Oxide, Propylene Oxide, and Beta-Propiolactone
What are 3 Gaseous Agents that are used in closed chambers to sterilize items?
treatment of disease
What are Antimicrobials typically used for?
Intermediate to Low-Level Disinfectants
What are level are Phenol and Phenolics?
Phenol Coefficient, Use-dilution test, and In-use test
What are the 3 methods for evaluating disinfectants and antiseptics?
Batch Method, Flash Pasteurization, and Ultrahigh-Temperature Pasteurization
What are the 3 methods of pasteurization used on milk?
Boiling, Autoclaving, Pasteurization, and Ultrahigh-Temperature Sterilization
What are the 4 methods of microbial control using moist heat?
Exposure to extremes of Heat, exposure to extremes of cold, desiccation, filtration, osmotic pressure, and radiation
What are the 6 physical methods of microbial control (in the order they are listed in our notes)?
Phenols, Alcohols, Halogens, Oxidizing Agents, Surfactants, Heavy Metals, Aldehydes, Gaseous Agents, and Antimicrobics
What are the 9 major categories of chemical methods of microbial control (in the order their listed in the notes)?
Transformation, Transduction, and Bacterial Conjugation
What are the Three types of Horizontal Gene Transfers?
RNA Primers, mRNA, rRNA, tRNA
What are the four types of RNA Transcribed from DNA?
Initiation, Elongation, and Termination
What are the three stages of Translation?
Self-Termination and Rho-Dependent Termination
What are the two types of Termination in RNA transcription?
Riboswitch and Short Interference RNA
What are the two ways of stopping Translation Directly to regulate protein synthesis and therefore regulate gene expression?
Hydrogen
What binds complementary base pairs together?
Chemicals, Radiation, and Heat altering or destroying Nucleic Acids
What can produce Fatal Mutations and can halt protein synthesis through action on RNA?
body materials
What can reduce the effectiveness of heat, disinfectants, and some forms of radiation?
Endospores, Protozoan cysts, and some viruses
What can survive boiling?
Denature proteins and disrupt Cell membranes
What do Alcohols do to cells?
Denature Proteins and disrupt Cell membranes
What do Phenol and Phenolics do to cells?
Protein Factors
What do all three of the stages of Translation require that assist Ribosomes?
Helicases, Topoisomerases, and Stabilizing Proteins
What do both bacteria and eukaryotes use in DNA replication?
Decrease microbial metabolism, growth, and reproduction
What do refrigeration and freezing do?
Thymine
What does Adenine bond with in DNA with 2 H bonds?
Uracil
What does Adenine bond with in RNA with 2 H bonds?
Vegetative cells of bacteria and fungi, protozoan trophozoites, and most viruses within 10 minutes at sea level
What does Boiling kill?
Cytosine
What does Guanine bond to with 3 H bonds?
all living microbes
What does Ultrahigh-temperature sterilization kill?
Denatures proteins and oxidizes metabolic and structural chemicals
What does dry heat do?
higher temperatures for longer time
What does dry heat require in comparison to moist heat?
a new RNA Primer
What does each Okazaki Fragment require?
its 3-D shape
What does protein function depend on?
Acidic conditions
What enhance antimicrobial effects of heat and some chemical disinfectants?
RNA Polymerases bind to the Promoter
What happens first in the Initiation of Transcription?
RNA Polymerase unwinds the two nucleotide strands
What happens in the Initiation of Transcription after the RNA Polymerases bind to the Promoter and the Sigma Factor recognizes the Promoter?
Initiation Complex
What is formed during Initiation of Translation?
Viral Envelope
What is responsible for the attachment of the virus to a target cell?
Dry heat
What is used for materials that cannot be sterilized with or are damaged by moist heat?
1% Silver Nitrate
What is used to prevent blindness caused by N. gonorrhoeae?
Psychrophilic microbes
What kind of microbes can multiply in refrigerated foods?
Intermediate-Level Disinfectants
What level are Alcohols?
Intermediate-Level Antimicrobial Chemicals
What level are Halogens?
High-Level Disinfectants and Antiseptics
What level are Oxidizing Agents?
Low-Level Disinfectants
What level are Quats?
Autoclaving
What method using moist heat uses pressure applied to boiling water, which prevents steam from escaping, allowing temperatures to rise exceed 100 degrees celcius at sea level?
Thermoduric and Thermophilic microbes
What microbes are able to survive pasteurizatioin, do not cause spoilage prior to consumption, and are generally not pathogenic?
Ultrahigh-Temperature Sterilization
What moist heat method involves exposing milk and other liquids to superheated steam at 140 degrees celcius for 1-3 seconds, then rapid cooling?
Batch method
What pasteurization method requires 30 minutes at 63 degrees Celcius?
Ultrahigh-temperature pasteurization
What pasteurization method requires a temperature of 134 degrees Celcius for 1 second?
Flash Pasteurization
What pasteurization method requires a temperature of 72 degrees celcius for 15 seconds (milk is run through heated tubes, effectively destroying all pathogens)?
Elongation
What stage of Translation involves the sequential addition of Amino Acids to a growing Polypeptide chain at the Ribosome's P Site?
In-Use test
What test gives an accurate determination of the proper strength and application procedure for each specific situation?
Use-dilution test
What test involves Metal cylinders being dipped into broth cultures of bacteria and dried, immersed into dilutions of disinfectants for 10 minutes, removed, washed, and placed into a tube of medium for 48 hours?
In-Use test
What test involves swabs being taken from objects before and after the application of Disinfectant or Antiseptic and inoculated into growth medium, which is then monitored for microbial growth?
Phenol Coefficient
What test is used for evaluating the efficacy of disinfectants and antiseptics by determining the ratio of the agent's ability to control microbes to that of Phenol?
Cytoplasmic membrane
What, when damaged, causes cellular contents to leak out?
Describe the process of polyadenylation in eukaryotic transcription?
When RNA polymerase reaches the end of a gene, termination proteins cleave the RNA molecule and add 100 to 250 adenine nucleotides to the 3' end. This occurs without a DNA template.
During self-termination, what happens when RNA polymerase transcribes the adenine-thymine rich portion of the terminator?
When RNA polymerase transcribes the adenine-thymine rich portion, the relatively few hydrogen bonds between the bases cannot withstand the tension and the RNA transcript breaks away from DNA, releasing the RNA polymerase.
Harsh chemicals and extreme heat
When taking into consideration the site to be treated by antimicrobial methods, one must take into account the fact that ______ ________ and ________ _____ cannot be used on humans, animals, and fragile objects.
health care settings, labs, and homes
Where are Phenol and Phenolics commonly used?
Nucleoid
Where does Transcription take place in Prokaryotes?
RNA Polymerase
Which Polymerase (RNA or DNA) does not require Helicase, since it unwinds and unzips DNA Helix?
DNA Polymerase
Which Polymerase is more efficient at proofreading?
Antiseptics
Which are milder; Antiseptics or Disinfectants?
nonionizing
Which has longer wavelength; Ionizing or nonionizing?
Ionizing
Which has shorter wavelength; Ionizing or nonionizing?
Fungi
Which have a greater ability to survive Hypertonic environments; Bacteria or Fungi?
Nonenveloped viruses
Which have a greater tolerance of harsh conditions; Enveloped Viruses or Nonenveloped Viruses?
Slow freezing
Which is more effective; slow freezing or quick freezing?
d
Which of the following are called "jumping genes"? a. Hfr cells b. transducing phages c. palindromic sequences d. transposons
c
Which of the following forms ionic bonds with eukaryotic DNA and stabilizes it? a. chromatin b. bacteriocin c. histone d. nucleoid
c
Which of the following is a true statement concerning prokaryotic chromosomes? a. They typically have two or three origins of replication b. They contain single-stranded DNA c. They are located in the cytosol d. They are associated in linear pairs
A (4,000,000)
Which of the following is most likely the number of base pairs in a bacterial chromosome? a. 4,000,000 b. 4000 c. 400 d. 40
c
Which of the following is not a mechanism of natural genetic transfer and recombination? a. transduction b. transformation c. transcription d. conjugation
c
Which of the following is not part of an operon? a. operator b. promoter c. origin d. gene
b
Which of the following is part of each molecule of mRNA? a. palindrome b. codon c. anticodon d. base pair
c
Which of the following methods of DNA repair involves enzymes that recognize and correct nucleotide errors in unmethylated strands of DNA? a. light repair of T dimers b. dark repair of P dimers c. mismatch repair d. SOS response
a
Which of the following molecules functions as a "proofreader" for a newly replicated strand of DNA? a. DNA polymerase III b. primase c. helicase d. ligase
a
Which of the following statements is true? a. conjugation requires a sex pilus extending from the surface of a cell b. conjugation involves a C factor c. conjugation is an artificial genetic engineering technique d. conjugation involves DNA that has been released into the environment
When Tryptophan is not present
With Transcription occuring, mRNA is made and enzymes for synthesizing Tryptophan are made, so it continues to be synthesized
When Lactose is not present
With no transcription, no mRNA is made, and no enzymes for catabolyzing Lactose are synthesized
When Lactose is present
With transcription occuring, mRNA is made, as are enzymes for catabolyzing Lactose
Radiation
X-rays and gamma rays damage DNA and proteins in cells make free radicals (ionizing) UV light- creates thymine dimers (non-ionizing) causes abnormal bonds between a.a.
Drying
________ inhibits growth due to the removal of water, only MICROBIOSTATIC.
Lactose
________ is the Inducer
Acidophiles
`bacteria that survive in a pH below 6.0 and make foods such as sour cream and yogurt
horizontal gene transfer among prokaryotes
a "donor cell" contributes part of its genome to a "recipient cell" which may be of a different species or even a different genus from the donor. Typically, the recipient cell inserts part of the donor's DNA into its own chromosome, becoming a recombinant cell Horizontal gene transfer is a rare event, typically occurring in less than 1% of the population of prokaryotes
Yersinia pestis
a Bacillus bacteria that causes plague, needs three virulence factors to be pathogenic
what happens in Transduction
a Virus picks up DNA from the donor cell it infects, and introduces it into a new host cell (recipient) which incorporates the donor DNA into its Genome
Transduction
a bacteriophage or phage carries DNA from a donor cell and injects it into a recipient cell. Can then go into a Lytic cycle which bacteria lyses open and releases new bacteriophages or a Lysogenic cycle where viral DNA combines into the chromosome
A pure culture of bacteria is typically derived from __________. -a single cell -a colony-forming unit -at least two cells -a group of cells
a colony-forming unit (It is possible for a colony to arise from a single cell.)
Regulatory Gene
a gene, often located some distance from the Operon, that directs continuous synthesis of a Repressor that blocks Transcription hwne it attaches to the Operator of and Operon
What does the slanted surface provides?
a larger surface area for aerobic microbial growth while the butt of the tube remains almost anaerobic
chromosomes
a molecule of DNA associated with protein. In prokaryotes, typically circular and localized in a region of the cytosol called the nucleoid. In eukaryotes, chromosomes are threadlike and are most visible during mitosis and meiosis.
Terminator Sequence
a nucleotide sequence composed mostly of Guanine-Cytosine Bases followed by a Sequence of mostly Adenine Bases
Death Pase
a population reaches a point a which cells die at a faster rate than they are produced
Quorum sensing is __________. -a process used by bacteria to detect population density and activate genes for new characteristics -an indirect method for microbiologists to measure the growth of bacterial populations -a mechanism used by bacteria to inactivate toxic forms of oxygen -a process used by bacteria to detect the osmotic pressure in their environment
a process used by bacteria to detect population density and activate genes for new characteristics
transformation
a recipient cell takes up DNA from the environment (such as DNA released by a dead organism)
A molecule that gains an electron from another molecule will experience ____________________ in its overall electrical charge, and becomes ________. . -a reduction, reduced -an increase, oxidized -a reduction, oxidized -an increase, reduced
a reduction, reduced
A psychrophile might grow best in which of the following environments? a thermal pool a refrigerator the human body a candle jar
a refrigerator
euchromatin
a region of DNA that is uncoiled and undergoing active transcription into RNA
Tryptophan Operon
a repressible operon
RNA Primer
a short RNA molecule that is complementary to the Parental DNA strand (the template) and provides a 3' end of a nucleic acid molecule to which DNA Nucleotides can be attached by DNA polymerase III
point mutations
a single nucleotide is affected insertions deletions substitutions
Saccharomyces cerevisiae
a yeast that has Plasmids
How many chromosomes are found in most bacterial cells?
a. 1 b. 2 c. 0 d. 23 e. 46 A
How many spaces for tRNAs exist inside the ribosome?
a. 1 b. 2 c. 3 d. 4 e. 5 C
Which concentration of ethanol is the most effective?
a. 100% b. 70% c. 50% d. 40% e. 30% B
Which of the following is most likely the number of base pairs in a bacterial chromosome? a. 4,000,000 b. 4000 c. 400 d. 40
a. 4,000,000
Assume a 1 ml aliqout is taken out of the third tube, and 50 colonies form on the plate. How many bacteria were in the original sample?
a. 50 CFU/ml b. 2500 CFU/ml c. 50,000 CFU/ml d. 500 CFU/ml e. 5,000 CFU/ml C
If a the coding strand on DNA reads A T T G T A G C C A, the complementary DNA will be
a. A T T G T A G C C A b. T A A C A T C G G T c. A U U G U A G C C A d. U A A C A U C G G U B
In translation, the site through which tRNA molecules leave a ribosome is called the
a. A site b. X site c. P site d. E site D
The endospores of which organism are used as biological indicator of sterilization? a. Bacillus stearothermophilus b. Salmonella enterica c. Mycobacterium tuberculosis d. Staphylococcus aureus
a. Bacillus stearothermophilus
Which of the following statements is true?
a. Conjugation requires sex pilus extending from the surface of a cell b.Conjugation involves a C factor c. Conjugation is an artificial genetic engineering technique d. conjucation involves DNA that has been released into the environment A
Which of the following is NOT directly involved in translation?
a. DNA b. mRNA c. tRNA d. ribosomes e. amino acids A
Transcription provides
a. DNA molecules b. RNA molecules c. Polypeptides d. Palindromes B
Which of the following molecules functions as a "proofreader" for a newly replicated strand of DNA? a. DNA polymerase III b. primase c. helicase d. ligase
a. DNA polymerase III
Which of the following are called "jumping genes?"
a. Hfr cells b. transducing phages c. palindromic sequences d. transposons D
Cells that have the ability to take up DNA from their environments are said to be
a. Hfr cells b. transposing c. genomic d. competent D
Which of the following is a true statement concerning prokaryotic chromosomes?
a. They typically have two or three origins of replication b. they contain single-stranded DNA c.they are located in the cytosol d.they are associated in linear pairs C
Non-ionizing radiation is
a. UV light b. gamma rays c. x-rays d. from nuclear fallout e. a and b only A
Which of the following is a halophile?
a. Vibrio sp. b. Clostridium sp. c. Lactobacillus sp. d. Bacillus sp. e. Treponemapallidum A
Which of the following items functions most like an autoclave?
a. a boiling pan b. an incinerator c. a microwave oven d. a perssure cooker D
A nucleotide is composed of
a. a five-carbon sugar b. phosphate c. a nitrogenous base d. all of the above D
A plasmid is
a. a molecule of RNA found in bacterial cells b. distinguished from a chromosome by being circular c. a structure in bacterial cells formed from plasma membrane d. extrachromosomal DNA D
A Coulter counter is
a. a statistical estimation using 15 dilution tubes and a table of numbers to estimate the number of bacteria per milliliter. b. an indirect method of counting microorganisms c. a device that directly counts microbes as they pass through a tube in front of an electronic detector d. a device that directly counts microbes that are differently stained with flourescent dyes C
In terms of a bacterium's optimal growth requirements, which group would you expect to be most likely involved in human infections?
a. acidophiles b. psychrophiles c. extreme halophiles d. mesophiles e. thermophiles D
Whichc of the following can grow in a Petri plate on a laboratory table?
a. an anaerobic bacterium b. an aerobic bacterium c. viruses on an agar surface d. all of the above B
Which of the following would you use to cleanse skin and mucous membranes?
a. an antiseptic b. a disinfectant c. a sterilizing agent d. all of the above e. a and b only A
Which of the following disinfectants contains alcohol?
a. an iodophor b. a quat c. formalin d. a tincture of bromine D
Which of the folowing substances or processes kills microorganisms on laboratory surfaces?
a. antiseptics b. disinfectants c. degermers d. pasteurization B
Quaternary ammonium compounds
a. are bacterial against all microbes and endospores b. are very effective against pseudomonads c. are rarely used due to their toxicity d. are composed of toxic oxygen products e. non of the above E
Which of the following does NOT kill endospores?
a. autoclave b. incineration c. hot air sterilization d. paseurization e. all of the above kill endospores D
Organisms that preferentially may thrive in icy waters are described as
a. barophiles b. thermophiles c. mesophiles d. psychrophiles D
This statement, "In the laboratory, a sterile inoculating loop is moved across the agar surface in a culture dish, thinning a sample and isolating individuals," describes which of the following?
a. broth culture b. pour plate c. streak plate d. dilution plate C
8. Barophiles a. cannot cause diseases in humans. b. live at normal barometric pressure. c. die if put under high pressure. d. thrive in warm air.
a. cannot cause disease in humans
Barophiles: a. cannot cause diseases in humans b. live at normal barometric pressure c. die if put under high pressure d. thrive in warm air
a. cannot cause diseases in humans
Nitrogen is needed by bacteria to synthesize
a. carbohydrates b. phospholipids c. ATP d. nucleotides e. c and d only E
Which of the following substances is least toxic to humans?
a. carbolic acid b. glutaraldehyde c. hydrogen peroxide d. formalin C
Nucleotides used in the replication of DNA
a. carry energy b. are found in four forms, each with a deoxyribose sugar, a phosphate, and a base c. are present in cells as triphosphate nucleotides d. all of the above D
Superoxide dismutase
a. causes hydrogen peroxide to become toxic b. detoxifies superoxide radicals c. neutralizes singlet oxygen d. is missing in aerobes B
Which of these chemicals is the least effective antimicrobial agent?
a. chlorine b. phenolics c. quaternary ammonium compounds d. iodine e. aldehydes C
Which of the following statements is true? a. conjugation requires a sex pilus extending from the surface of a cell. b. conjugation involves a C factor c. conjugation is an artificial genetic engineering technique d. conjugation involves DNA that has been released into the environment.
a. conjugation requires a sex pilus extending from the surface of a cell.
which of the following chemicals is active against bacterial endospores?
a. copper ions b. ethylene oxide c. ethanol d. triclosan B
Althought two cells are totally unrelated, one cell receices DNA from teh other cell and incorporates this new DNA into its chromosome. This process is:
a. crossing over of DNA from the two cells b. vertical gene transfer c. horizontal gene transfer d. transposition C
Salts and sugars work to preserve foods by creating a
a. depletion of nutrients b. hypotonic environment c. hyperacidic environment d. hypertonic environmen e. a and b only D
Which of the following adjectives best describes a surgical procedure that is free of microbial contaminants?
a. disinfected b. sanitized c. degermed d. aseptic D
Biosafety Level 3 includes a. double sets of entry doors b. pressured suits c. showers entryways d. all of the above
a. double sets of entry doors
Biosafety Level 3 includes
a. double sets of entry doors b. pressurized suits c. showers in entryways d. all of the above D
Which of the following is best to sterilize heat labile solutions?
a. dry heat b. autoclave c. membrane filtration d. pasteurization e. non of the above C
Which of the following methods is best for counting fecal bacteria from a stream to determine the safety of the water for drinking?
a. dry weight b. turbidity c. viable plate counts d. membrane filtration D
Which of the following types of radiation is more widely used as an antimicrobial technique? a. electron beams b. visible light waves c. radio waves d. microwaves
a. electron beams
Which of the following types of radiation is more widely used as an antimicrobial technique?
a. electron beams b. visible light waves c. radio waves d. microwaves C
The preservation of beef jerky from microbial growth relies on which of the microbial control?
a. filtration b. lyophilization c. desiccation d. radiation
14. Lyophilization can be described as a. freeze-drying. b. deep-freezing. c. refrigeration. d. pickling.
a. freeze-drying
Lyophilization can be described as a. freeze-drying b. deep-freezing c. refrigeration d. pickling
a. freeze-drying
Lyophilization can be described as
a. freeze-drying b. deep-freezing c. refrigeration d. pickling A
Bacteriophages can contribute to bacterial virulence because bacterophages
a. give new gene sequences to the host bacteria b. produce toxins c. carry plasmids d. kill the bacteria causing release of bacterocins e. all of the above A
A naked virus a. has no membranous envelope b. has injected its DNA or RNA into a host cell c. is devoid of capsomeres d. is one that is unattached to a host cell
a. has no membranous envelope
Insertion sequence transposons contain
a. inverted repeats b. a gene for transposase c. resistance plasmids d. F factors e. a and b only E
Which of the following is often used for sterilizing plastic petri plates?
a. ionizing radiation b. ethylene oxide gas c. glutaraldehyde d. autoclave e. a and b only E
Which of the following is not true of a gene?
a. is a specific linear sequence of DNA b. is the functional unit of a chromosome c. contains an information code for a protein d. usually codes for a single trait e. made up of a sequence of amino acids E
Ligase plays a major role in a. lagging strand replication b. mRNA processing in eukaryotes c. polypeptide synthesis by ribosomes d. RNA transcription
a. lagging strand replication
In what phase of a bacterial growth curve is ther a time of acclimation, during which cells are metabolically active, but there is no increase in cell numbers?
a. log phase b. lag phase c. stationary phase d. decline phase e. generation phase B
What role do resistance plasmids and resistance genes play?
a. make bacteria resistant to bacteriophage b. make bacteria resistant to certian antimicrobial drugs c. make bacteria resistant to recombination d. make bacteria resistant to certian bacteriocins e. make bacteria reisistant to heat B
The addition of --- CH3 to a cytosine nucleotide after DNA replication is called: a. methylation b. restriction c. transcription d. transversion
a. methylation
Which of the following molecules functions as a "proofreader" for a newly replicated strand of DNA?
a. methylation b. restriction c. helicase d. ligase A
Most bacteria divide by a process called
a. mitosis b. binary fission c. sporulation d. meiosis e. conjugation B
Which of the following terms best descrives an organism that cannot exist in the presence of oxygen?
a. obligate aerobe b. facultative aerobe c. obligate anaerobe d. facultative anaerobe C
Bacteria that can live in the presence of oxygen but do not use oxygen as a final electron acceptor are called
a. obligate anaerobes b. facultative anaerobes c. photoautotrophic d. chemoautotrophic e. a and b only D
Which of the following is part of each molecule of mRNA?
a. palindrome b. codon c. anticodon d. base pair B
Which of the folowing terms best describes the disinfecting of cafeteria plates?
a. pasteurization b. antisepsis c. sterilization d. sanitization D
A virus that is specific for a bacterial host is called a a. phage b. prion c. virion d. viroid
a. phage
Which of the following acts against cell membranes a. phenol b. peracetic acid c. silver nitrate d. glutaraldehyde
a. phenol
Which of the following substances would most effectively inhibit anaerobes?
a. phenol b. silver c. ethanol d. hydrogen peroxide A
Cyanobacteria
a. photoheterotrophic b. chemoheterotrophic c. photoautotrophic d. chemoautotrophic e. a and b only C
Pathogenic strains of Streptococcus pneumoniae have
a. pili b. capsules c. endotoxins d. lysogenic bacteriophages e. c and d only B
A protein secreted by some bacteria that kills other bacterial strains is called a
a. plasmid b. lethal factor c. bacteriocin d. resistance transfer factor e. microbicide C
Which of the following is mismatched?
a. psychrophiles-growth range from 0-20 degrees C b. halophiles-prefer alkaline pHs c. acidophiles-prefer pHs below 7 d. thermophiles-growth range above 45 degrees C e. mesophile-growth range from 25-40 degrees C B
Which class of surfactant is most soluble in water? a. quaternary ammonium compounds b. alcohol c. soaps d. peracetic acids
a. quaternary ammonium compounds
Which of the following best describes the action of nucleotide analogs on DNA?
a. removes amino groups from nitrogenous bases b. acts as a "false" nucleotide c. removes water from nitrogenous bases d. adds a methyl group to a nitrogenous base e. forms thymine-thymine dimers on the DNA molecule B
Which of the following is not a heavy metal?
a. sliver nitrate b. mercurochrome c. merthiolate d. copper e. chlorine E
In ___________ transduction, only genes adjacent to the viral insertion site are transferred to a new host cell
a. specialized b. generalized A
In practical terms in everyday use, which of the following statements provides the definition of sterilization? a. sterilization eliminates organisms and their spores or endospores b. sterilization eliminates harmful microorganims and viruses c. sterilization eliminates prions d. sterilization eliminates hyperthermophiles
a. sterilization eliminates organisms and their spores or endospores
15. Quorum sensing is a. the ability to respond to changes in population density. b. a characteristic of most bacteria. c. dependent on direct contact among cells. d. associated with colonies on an agar plate.
a. the ability to respond to changes in population density
Quorum sensing a. the ability to respond to changes in population density b. a characteristic of most bacteria c. dependent on direct contact among cells d. associated with colonies on an agar plate
a. the ability to respond to changes in population density
Quorum sensing is
a. the ability to respond to changes in population density b. a characteristic of most bacteria c. dependent on direct contact among cells d. associated with colonies on an apgar plate A
Sanitation refers to
a. the destruction of all forms of microbial life on an object b. a chemical that kills allmicrobes but not enveloped viruses c. the removal of microbes from the skin d. reducing pathogens to ssafe public health levels e. the sterilization of cooking utensils D
10. In a defined medium, a. the exact chemical composition of the medium is known. b. agar is available for microbial nutrition. c. blood may be included. d. organic chemicals are excluded.
a. the exact chemical composition of the medium is known
In a defined medium,
a. the exact chemical composition of the medium is known b. agar is available for microbial nutrition c. blood may be included d. organic chemicals are excluded A
In a defined medium a. the exact chemical composition of the medium is known. b. agar is available for microbial nutrition c. blood may be included d. organic chemicals are excluded
a. the exact chemical composition of the medium is known.
4. The most reactive of the four toxic forms of oxygen is a. the hydroxyl radical. b. the peroxide anion. c. facultative anaerobes. d. fastidious.
a. the hydroxyl radical
The most reactive of the four toxic forms of oxygen is a. the hydroxyl radical b. the peroxide anion c. the superoxide d. singlet oxygen
a. the hydroxyl radical
The most reactive of the four toxic forms of oxygen is
a. the hydroxyl radical b. the peroxide anion c. the superoxide radical d. singlet oxygen A
Protein synthesis ends when
a. there are no more tRNAs in teh cytoplasm b. RNA polymerase falls off the coding strand of DNA c. a stop codon is reached in the ribosome d. one ribosome is bumped off by another ribosome e. a mutation occurs C
The optimal growth temperature of a bacterium is MOST closely related to the optimal temperature for
a. transcription of DNA b. DNA replication c. spore formation d. functioning of enzymes e. mRNA attachment to ribosomes D
The uptake and incorporation of DNA from the environment by bacteria is called
a. transduction b. transcription c. translation d. transmogrification e. transformation E
Which of the following is not a mechanism of natural genetic transfer and recombination?
a. transduction b. transformation c. transcription d. conjugation C
During transcription, DNA serves as a template for the synthesis of mRNA
a. true b. false A
Gene transfers are beneficial to bacteria because they increase genetic diversity
a. true b. false A
in pre-RNA processing, introns are removed, and exons are spliced together
a. true b. false A
Griffith's experiment proved that bacteria are capable of conjugation
a. true b. false B
Ionizing radiation damages cells because it induces the formation of thymine dimers
a. true b. false B
Microbial growht is typically measured by increase in cell size
a. true b. false B
Mutations in an organism's genotype will always affect its phenotype
a. true b. false B
The Ames test: a. uses auxotrophs and liver extract to reveal mutagens b. is time intensive and costly c. involves the isolation of a mutant by eliminating wild-type phenotypes with specific media. d. proves that suspected chemicals are carcinogenic
a. uses auxotrophs and liver extract to reveal mutagens
Another name for a complete virus is a. virion b. viroid c. prion d. capsid
a. virion
Two carbons from pyruvic acid join conenzyme A to form _________, (_________), which then enters the Kreb's cycle, a series of 8 enzymatic steps that transfer __________ from Acetyl CoA to coenzymes _________and ________.
acetyl-coenzyme A (acetyl CoA);electrons; NAD+ and FAD
-the amount of energy needed to initiate a chemical reaction
activation energy
Substrates fit into the specifically shaped ________ _______ of the enzymes that catalyze their reactions.
active sites
Cyanide poisoning _______________________.(may be more than one answer) -allows for ATP production without using oxygen as a terminal electron acceptor. -diverts the energy from the proton gradient to other cell functions. -acts in a manner similar to oxygen deprivation. -blocks cytochrome a3.
acts in a manner similar to oxygen deprivation. blocks cytochrome a3.
successful in limiting influenza infection, block attachment of flu virus
adamantanes, neuraminidase inhibitors
AZT is an analog to what base
adenine
Metabolic processes are guided by eight elementary statements. Statement 3: Energy is stored in the chemical bonds of _______________ ________________ a.k.a. ATP.
adenosine triphosphate
Microaerophiles (detoxify what)
aerobes that require oxygen levels from 2-10% and have a limited ability to detoxify hydrogen peroxide and superoxide radicals
Which of the following groups of microbes does not undergo aerobic metabolism, but can detoxify oxygen enough to live in its presence? microaerophiles obligate anaerobes aerotolerant anaerobes facultative anaerobes
aerotolerant anaerobes
Chemical methods of microbial control
affect microbes' cell walls, cytoplasmic membranes, proteins, or DNA
DNA Helicase
after the chromosomal enzymes are removed, this enzyme that separates two DNA nucleotide strands by breaking H bonds between Nitrogen bases, creating a Replication Fork
Bactericide, Fungicide, Virucide
agents that kill or permanently inactivate Bacteria, Fungi, and Viruses, respectively
colony
aggregations of cells arising form a single parent cell
turbidity
aim light through a broth, counts dead cells as well
In fermentation, pyruvic acid is generally converted into organic waste products such as________and _________.
alcohol and lactic acid.
Ex of obligate aerobes?
algae, most fungi, and protozoa, and many prokaryotes
What are the products of noncyclic photophosphorylation? oxygen ATP NADPH all of the above none of the above
all of the above
Which macromolecule can be used directly by glycolysis? lipids proteins nucleic acids carbohydrates all of the above none of the above
all of the above
Which of the following is a product of alcohol fermentation?(possibly more than one answer) carbon dioxide ethanol NAD+ #2 and #3 all of the above
all of the above
Which of the following statements are true regarding the energy-investment stage? -It can occur only in a cell with ATP to invest. -Two molecules of ATP are used during this step. -Fructose-1,6-bisphosphate is an intermediate of this stage. -all of the above -none of the above
all of the above
Photoautotrophs
all organisms that produce organic molecules from inorganic molecules using the energy of light (algae, cynobacteria)
Defined media is called like this because?
all the components known and more exclusive for the bacteria that grow within it
Feedback inhibitiob (negative feedback) occurs when the final product of a series of reactions is an __________ ________ of some previous step in the series.
allosteric inhibitor
Uncoupling proteins _______________________. -prevent the ETC from reducing oxygen. -allow the electron transport system to be used for tasks other than ATP production. -synthesize ATP. -pass electrons to the final electron acceptor.
allow the electron transport system to be used for tasks other than ATP production
Nucleotide-Altering Chemicals
alter the structure of nucleotides (base pair substitutions) ex. nitrous acid, nitrosamines (meats) aflatoxins(found in peanut butter cause liver cancer)
antibiotics that contain amino sugars bonded by glycosidic linkage. Examples: kanamycin, neomycin, amikacin. Not commonly used today because of neurotoxicity/nephrotoxicity; considered reserve antibiotics for when others fail
aminoglycosides
Gluconeogenesis is _________________________. nvolved in lipid synthesis. a catabolic pathway. a process that produces pyruvic acid. an anabolic pathway
an anabolic pathway.
DNA replication
an anabolic polymerization process that requires monomers and energy
microbial growth
an increase in a population of microbes rather than an increase in size of an individual
Lactose Operon
an inducible operon
Photoheterotrophs
an organism that obtains energy from sunlight and carbon from organic sources (purple & green non-sulfur bacteria)
Which of the following enzymes might be expected to catalyze the addition or removal of electrons associated with other molecules? -a transferase -a ligase -an oxidoreductase -an isomerase
an oxidoreductase
According to the eight statements that guide the metabolic processes, using the building block precurser metabolites, energy from ATP, and other enzymes, cells construct larger building blocks in _____________(______________) reactions.
anabolic (biosynthetic)
Nitrogen is often a growth limit for many organisms; that is, their_
anabolism ceases because they do not have sufficient nitrogen to build proteins and nucleotides
Clostridium botulinum
anaerobic bacterium producing botulin the toxin that causes botulism, anaerobic in soil, produces endospores, only transduced strains are pathogenic
chemical substance produced by a microorganism that kills or inhibits the growth of another microorganism
antibiotic
Erythromycin
antibiotic that binds only to Prokaryotic Ribosomes and interferes with their function, but has no effect on Eukaryotic Ribosomes
a chemical agent that kills or inhibits growth of microorganisms
antimicrobial agent
the acquired ability of a microorganism to grow in the presence of an antimicrobial drug to which the microorganism is usually susceptible
antimicrobial drug resistance
chemical agent that kills or inhibits growth of microorganisms and is sufficiently nontoxic to be applied to living tissues, i.e. mouthwash
antiseptic (germicide)
-the portions of enzymes that may require one or more cofactors such as iorganic ions or organic cofactors.
apoenzymes (aka coenzymes)
Ions
are Antimicrobial because they alter the 3-D shape of Proteins, inhibiting or eliminating their function
Hydrolysis reactions __________. -involve removal of hydrogen from a molecule -release water -are used to synthesize compounds -are catabolic
are catabolic
Eukaryotic Chromosomes
are composed of DNA wrapped around Histones, forming Nucleosomes that are connected by Linker DNA
Eukaryotic genomes
are contained in 2 structures; Nuclear DNA (chromosomes within the nucleus) and Extranuclear DNA (chromosomes within Mitochondria and Chloroplasts)
Chromatin Fibers
are formed by the clumping together of Nucleosomes
normal microbiota
are microorganisms associated with a certain area of the body without causing a disease
Most of the glyceraldehyde 3-phosphate molecules produced in the Calvin Benson cycle __________________________. -are used in the production of sugar. -are used to regenerate NADP+. -are used to regenerate ribulose bisphosphate. -are broken down to yield ATP.
are used to regenerate ribulose bisphosphate.
Replication Fork
area where 2 DNA strands are separated and Nitrogen Bases are exposed
Stationary Phase
as nutrients are depleted and wastes accumulate, the rate of reproduction decrease. The number of dying cells equals the number of cells being produced population remains constant.
Polyadenylation
at the end of the Gene, Termination Proteins separate the RNA molecule and add about 200 Adenine Nucleotides to the 3' end
a sterilizer that destroys microorganisms with temperature and steam under pressure
autoclave
what is wrong with a person that has Type I diabetes ?
b cells of pancreas do not make insulin.
Which of the following is not a growth factor for various microbes? a. cholesterol b. water c. vitamins d. heme
b water
Transcription produces: a. DNA molecules b. RNA molecules c. polypeptides d. palindromes
b. RNA molecules
Repressible operons are important in regulating prokaryotic a. DNA replication b. RNA transcription c. rRNA processing d. sugar catabolism
b. RNA transcription
A clear zone of phage infection in a bacterial lawn is a. a prophage b. a plaque c. naked d. a zone of inhibition
b. a plaque
11. Which of the following is most useful in representing population growth on a graph? a. logarithmic reproduction of the growth curve b. a semilogarithmic graph using a log scale on the y-axis c. an arithmetic graph of the lag phase followed by a logarithmic section for the log, stationary, and death phases d. none of the above would best represent a population growth curve
b. a semilogarithmic graph using a log scale on the y-axis
Which of the following is most useful in representing population growth on a graph? a. logarithmic reproduction of the growth curve b. a semilogarithmic graph using a log scale on the y-axis c. an arithmetic graph of the lag phase followed by a logarithmic section for the log. stationary, and death phases d. one of the above would best represent a population growth curve
b. a semilogarithmic graph using a log scale on the y-axis
The trp operon is repressible. This means it is usually ________ and is directly controlled by _________. a. active/ an inducer b. active/ a repressor c. inactive/ an inducer d. inactive/ a repressor
b. active/ a repressor
A sequence of nucleotides formed during replication of the lagging DNA strand is a. a palindrome b. an Okazaki fragment c. a template strand d. an operon
b. an Okazaki fragment
1. Which of the following can grow in a Petri plate on a laboratory table? a. an anaerobic bacterium b. an aerobic bacterium c. viruses on an agar surface d. all of the above
b. an aerobic bacterium
Which of the following can grow in a Petri dish a. am anaerobic bacterium b. an aerobic bacterium c. viruses on an agar surface d. all of the above
b. an aerobic bacterium
5. Microaerophiles that grow best with a high concentration of carbon dioxide in addition to a low level of oxygen are called a. aerotolerant. b. capnophiles. c. facultative anaerobes. d. fastidious.
b. capnophiles
Microaerophiles that grow best with a high concentration of carbon dioxide in addition to a low level oxygen are called: a. aerotolerant b. capnophiles c. facultative anaerobes d. fastidious
b. capnophiles
Which of the following is part of each molecule of mRNA? a. palindrome b. codon c. anticodon d. base pair
b. codon
A DNA gene synthesized from an RNA template is_ a. reverse transcriptase b. complementary DNA c. Recombinant DNA d. Probe DNA
b. complementary DNA
3. Superoxide dismutase a. causes hydrogen peroxide to become toxic. b. detoxifies superoxide radicals. c. neutralizes singlet oxygen. d. is missing in aerobes.
b. detoxifies superoxide radicals
Superoxide dismutase a. causes hydrogen peroxide to become toxic b. detoxifies superoxide radicals c. neutralizes singlet oxygen d. is missing in aerobes
b. detoxifies superoxide radicals
Which of the following substances or processes kills microorganisms on laboratory surface? a. antiseptics b. disinfectants c. degermers d. pasteurization
b. disinfectants
Which of the following is false? a. Viruses may have circular DNA b. dsRNA is found in bacteria more often than in viruses c. Viral DNA may be linear d. Typically, viruses have DNA or RNA, but not both
b. dsRNA is found in bacteria more often than in viruses
Which of the following chemicals is active against bacterial endospores? a. copper ions b. ethylene oxide c. ethanol d. triclosan
b. ethylene oxide
6. Which of the following is not a growth factor for various microbes? a. cholesterol b. water c. vitamins d. heme
b. water
Which of the following is not a growth factor for various microbes? a. cholesterol b. water c. vitamins d. heme
b. water
plasmids are only found in which organism?
bacteria
Neisseria gonorrhoeae
bacteria that are provided resistance to Penicillin by R Factors (acquired from Penicillin-resistant strains of Streptococci)
Mycobacterium tuberculosis
bacteria that causes tuberculosis, obligate aerobe. Acid fast staining required, chest xray, or tb skin test.
The pour-plate technique is a method used to isolate__________.
bacteria.
Vitamins are considered a growth factor for _________.
bacteria.
an agent that kills bacteria
bacteriocidal agent
an agent that inhibits bacterial growth
bacteriostatic agent
Agrobacterium
bacterium that forms Galls in plants and transfers some of its genes into plant chromosomes through conjugation
A microbe isolated from deep in the ocean could best be characterized as a __________.
barophile and psychrophile
Mutation in genotype & phenotype
base pair sequence in DNA always changes in mutation, a change in genotype does not always change in phenotype
Nucleosomes
beads of DNA and Histones
electronic counters
beams are aimed and the specimen is dropped through it, where ever there is a microbe the beam is interrupted it counts used in hospitals for blood counts.
When clinical specimens are collected in order to identify a suspected pathogen, why we have to isolate them?
because they are together with normal microbiota
Why Hydroxyl does not affect aerobes?
becuase hydrogen perioxide does not accumulate in aerobic cells due to catalase and perioxidase
DNA replication in eukaryotes
before mitosis or meosis starts, starts in many places.
Which process is INCORRECTLY matched with its location in bacteria? -fermentation: cytoplasm -beta-oxidation: mitochondria -Krebs cycle: cytoplasm -glycolysis: cytoplasm
beta-oxidation: mitochondria
The majority of bacteria reproduce using __________. -spontaneous generation -mitosis -binary fission -meiosis
binary fission
A competitive inhibitor _______________________. -gives products the same as the intended substrate. -speeds up catalysis of the original substrate. -binds to the substrate. -binds to the active site.
binds to the active site.
Given that many microorganisms become more harmful when they are part of a_
biofilm
Organized collections of bacteria that attach to surfaces and are associated with many disease processes are called __________.
biofilms
How does sulfonamide work?
block a step in the folic acid synthesis pathway by acting as a competitive inhibitor to PABA, prevents synth of folic acid and therefore nucleic acids, unable to reproduce
How do nucleoside analogs work as antivirals?
block reverse transcriptase and production of viral DNA
How do quinolones/fluorquinolones work?
blocks function of DNA gyrase
How does rifampin work?
blocks function of RNA polymerase
How does cipro (quinolones) work?
blocks the function of DNA gyrase used to treat anthrax
When catabolic pathways break down large molecules they release energy, cells store some of this released energy energy in the __________of ATP, though much of the energy is lost as ___________.
bonds;heat
Glutaraldehyde
both disinfects (with short exposure) and sterilized (with long exposure)
Another term for the Calvin Benson Cycle is _____________________________. the light-independent reactions. the dark reactions. both of the above. neither of the above
both of the above.
Which photosystem does noncyclic photophosphorylation utilize? photosystem I photosystem II both photosystem I and II neither photosystem I or II
both photosystem I and II
Catabolic reactions are chemical reactions that __________. -release molecules of water -involve carbon -break large molecules apart -consume energy
break large molecules apart
tRNA
brings Amino Acids to Ribosomes
the electrophoresis chamber is filled with_
buffer solution and agarose (similar to agar)
How cells regulate protein synthesis
by haulting mRNA transcription or stopping Translation directly
Which of the following statements is true? a. Viruses move toward their host cell b. Viruses are capable of metabolism c. Viruses lack a cytoplasmic membrane d. Viruses grow in response to their environmental conditions
c. Viruses lack a cytoplasmic membrane
13. A Coulter counter is a. a statistical estimation using 15 dilution tubes and a table of numbers to estimate the number of bacteria per milliliter. b. an indirect method of counting microorganisms. c. a device that directly counts microbes as they pass through a tube in front of an electronic detector. d. a device that directly counts microbes that are differentially stained with fluorescent dyes.
c. a device that directly counts microbes as they pass through a tube in front of an electronic detector.
A Coulter counter is a. a statistical estimation using 15 dilution tubes and a table of numbers to estimate the number of bacteria per milliliter. b. an indirect method of counting microorganisms c. a device that directly counts microbes as they pass through a tube in front of an electronic detector. d. a device that directly counts the microbes that are differently stained with florescent dyes.
c. a device that directly counts microbes as they pass through a tube in front of an electronic detector.
When eukaryotic cell is infected with an enveloped virus and sheds viruses slowly over time, this infections is a. called a lytic infection b. a prophage cycle c. called a persistent infection d. caused by a quiescent virus
c. called a persistent infection
A sample of E. coli has been subjected to heat for a specified time, and 90% of the cells have been destroyed. Which of the following terms best describes this event? a. thermal death point b. thermal death time c. decimal reduction time d. none of the above
c. decimal reduction time
The preservation of beef jerky from microbial growth relies on which method of microbial control? a. filtration b. lyophilization c. desiccation d. radiation
c. desiccation
Which of the following forms ionic bonds with eukaryotic DNA and stabilizes it? a. chromatin b. bacterium c. histone d. nucleoid
c. histone
Although two cells are totally unrelated, one cell receives DNA from the other cell and incorporates this new DNA into its chromosome. This process is a. crossing over of DNA from two cells b. vertical gene transfer c. horizontal gene transfer d. transposition
c. horizontal gene transfer
Which of the following substances is least toxic to humans? a. carbolic acid b. glutaraldehyde c. hydrogen peroxide d. formalin
c. hydrogen peroxide
Which of the following methods of DNA repair involves enzymes that recognize correct nucleotide errors in unmethylated strands of DNA? a. light repair of T dimes b. dark repair of P dimers c. mismatch repair d. SOS response
c. mismatch repair
9. Which of the following terms best describes an organism that cannot exist in the presence of oxygen? a. obligate aerobe b. facultative aerobe c. obligate anaerobe d. facultative anaerobe
c. obligate anaerobe
Which of the following terms best describes an organism that cannot exist in the presence of oxygen? a. obligate aerobe b. facultative aerobe c. obligate anaerobe d. facultative anaerobe
c. obligate anaerobe
Which of the following is not part of operon? a. operator b. promoter c. origin d. gene
c. origin
Which of the following is not an acellular agent? a. viroid b. virus c. rickesttsia d. prion
c. rickesttsia
2. This statement, "In the laboratory, a sterile inoculating loop is moved across the agar surface in a culture dish, thinning a sample and isolating individuals," describes which of the following? a. broth culture b. pour plate c. streak plate d. dilution plate
c. streak plate
This statement, "In the laboratory, a sterile inoculating loop moved across the agar surface in a culture dish, thinning a sample and isolating individuals," describes which of the following? a. broth culture b. pour plate c. streak plate d. dilution plate
c. streak plate
Which of the following is a true statement concerning prokaryotic chromosomes? a. they typically have two or three origins b. they contain single-stranded DNA c. they are located in the cytosol d. they are associated in linear pairs
c. they are located in the cytosol
Which of the following is not a mechanism of natural genetic transfer and recombination? a. transduction b. transformation c. transcription d. conjugation
c. transcription
In DNA, adenine forms _________ hydrogen bonds with ___________. a. three/uracil b. two/uracil c. two/thymine d. three/thymine
c. two/thymine
An obligate anaerobe __________. -can be cultured in a GasPak -grow throughout thioglycollate broth -possess catalase and peroxidase -can survive in the presence of superoxide radicals, but not free oxygen
can be cultured in a GasPak
Facultative anaerobes
can maintain life via fermentation or anaerobic respiration or by aerobic respiration
conjugation
can occur among a wide range of bacteria; even between bacterium and yeast cells or between bacterium and plant cell
yes
can the recipient of Horizontal Gene Transfers be a different species or even genus than the donor?
A candle jar would be most useful in isolating which of the following? -fastidious microbes -capnophiles - psychrophiles -biofilms
capnophiles
Which of the following is an inorganic carbon source? -glucose -triglycerides -carbon dioxide -amylose
carbon dioxide
RuBP, which stands for ribulose 1,5-bisphosphate, is necessary for ________ ________ during the Calvin-Benson cycle that occurs as part of the light-independent reactions of photosynthesis.
carbon fixation
1. All cells require sources of
carbon, energy, and electrons.
All cells require sources of _________, __________, and __________.
carbon, energy, electrons
8. ______ pigments protect many phototrophic organisms from photochemically produced singlet oxygen.
carotenoids
mRNA
carries genetic information copied from DNA to Ribosomes
R plasmids
carry genes for antibiotic resistance Escherichia Coli
The breakdown of lipids into glycerol and fatty acids is an example of what type of pathway?
catabolic pathway
Cells have __________pathways which break larger molecules into smaller products (a.k.a. breaking down), and ___________pathways which synthesize large molecule from the smaller products of catabolism. (building up)
catabolic;anabolic
Metabolism can be divided into what two major classes of reactions?
catabolism and anabolism
How do you separate staph from strep?
catalase test Staph is catalase positive Strep is catalase neg
Organic ______________called enzymes, make metabolism possible.
catalysts
How does UV radiation kill cells? What is it used for? What are its downfalls?
causes TT dimer mutations, more exposure causes more mutations and cells are unable to repair themselves. Useful for decontamination of surfaces, often used in A/C ducts and surgery rooms to disinfect air Cannot penetrate solid, opaque, or light-absorbing surfaces, or glass
UV light
causes the formation of pyrimidine dimers in DNA and does not penetrate well
Capping
cell adds Guanine Nucleotide to the 5' end of the RNA molecule
Lag Phase
cells are adjusting to their new environment they do not reproduce immediately but instead they actively sythesize enzymes to utilize novel nutrients in the medium.
Wild Types
cells normally found in nature
competent cells
cells that have the ability to take up DNA from their environment
The number of ATP molecules produced from the complete aerobic oxidation of one glucose molecule is given as a theoretical number because __________. -glucose can never be completely oxidized aerobically -some of the ATP produced by aerobic oxidation diffuses out of the cell before it can be used -cells use proton gradients for processes other than ATP production -the process of ATP production is not completely understood on the molecular level
cells use proton gradients for processes other than ATP production
Recombinants
cells with DNA molecules that contain New Nucleotide Sequences
Fill in the blanks below, being sure to refer to the exergonic pathways of catabolism. When catabolic pathways break down large molecules, they release energy. ____________store some of this released energy in the bonds of ATP, though ______of the energy is lost as heat. Another result of the breakdown of large molecules by cataboic pathways is the production of numerous smaller molecules, some of which are ______________ ____________ of anabolism.
cells;much;precurser metabolites
-a metabolic process that involves the complete oxidation of substrate molecules and the production of ATP following a series of redox reactions
cellular respiration
Proton gradients are produced during _______ ________.
cellular respiration
produced by fungus Cephalosporium, same mode of action as penicillins, commonly used to treat gonorrhea
cephalosporins
Mutation
change in sequence of the nucleotides(AGUTC) in DNA
Mutation
change in the Nucleotide Base Sequence of a Genome
Bidirectional
characteristic of Bacterial DNA replication meaning it proceeds in both directions from the origin
Germicide
chemical agent that destroys pathogenic microbes in general
Metabolic processes are guided by eight elementary statements. Statement 1: Every cells acquires nutrients, which are the ____________ necessary for metabolism.
chemicals
_plays a secondary role to the mechanical removalof microbes
chemicals
Frameshift Mutagens
chemicals that insert into the DNA Helix, allowing Base Pair Insertions or Deletions resulting in Nonsense Mutations
Frame shift chemical mutagens
chemicals with the shape of the base pares, insert or delete nucleotide base pairs
-These organisms use chemical forms of energy and they obtain their carbon from inorganic sources.
chemoautotrophs
Most pathogenic bacteria would be classified as __________. -photoautotrophs -chemoautotrophs -photoheterotrophs -chemoheterotrophs
chemoheterotrophs
What do anti fungal drugs usually target?
chitin cell walls, sterols in cytoplasmic membrane, folate biosynthesis, disrupt microtubule aggregation
The site of photosynthesis within a photosynthetic eukaryotic cell is the __________. -chloroplast -nucleus -mitochondrion -cytoplasm
chloroplast
petri dishes
clear, flat, culture dishes with loose-fitting lids
transport media
clinical specimens are transported in transport media that are chemically formulated to maintain the relative abundance of different microbial species or to maintain an anaerobic environment
Exons
coding sequences
A triplet of mRNA nucleotides that specifies a particular amino acid is called a _________
codon
A triplet of mRNA nucleotides that specifies a particular amino acid is called a _____________.
codon
Many vitamins are important for metabolism because they act as __________. ribozymes holoenzymes apoenzymes coenzymes
coenzymes
biofilm
collection of microbes living on a surface in a complex community
medium
collection of nutrients used for cultivating microorganisms
All of the following are associated with the streak plate method of isolation EXCEPT __________. -colonies will be found growing at and below the surface of the medium -a sterile inoculating loop or needle is used -the purpose is to isolate colony-forming units (CFUs) from one another -a solid medium in a Petri dish is used in this technique
colonies will be found growing at and below the surface of the medium
Quats
colorless, tasteless, harmless to humans, and Antimicrobial; ideal for many medical and industrial applications
rRNA
combines with Ribosomal Polypeptides to form Ribosomes
-block active site and thereby block enzyme activity
competetive inhibitors
Sulfanilamide is a drug that interferes with bacterial enzymes in which of the following ways? -end-product inhibition -feedback inhibition -noncompetitive inhibition -competitive inhibition
competitive inhibition
what is more commonly used: defined media or complex media?
complex media
Since it contains actual blood, blood agar supplies a variety of growth factors, making it a__________ __________.
complex medium
Nucleotide Analogs
compounds similar in structure to Nucleotides; they disrupt DNA and RNA replication and cause POINT MUTATIONS
Dissimilation Plasmids
contain genes that enable the bacterium to catabolize unusual substances
mRNA
contains genetic code from DNA dictates order of amino acids in protein
Microbial metabolism- the collection _______________ biochemal reactions that takes place within the microbe.
controlled
used to kill algae in pools
copper sulfate
Proton gradients can be used for active transport, flagellar motion, and ATP production, but Electron transport is a means by which a proton gradient is _______, not _______.
created;not used
_______________ ______________ is a recombination event that occurs during gamete formation in eukaryotes.
crossing over
what examples of bacteria can utilize the 79% of nitrogen gas in the atmosphere?
cyanobacteria Rhizobium
Chloroplasts found in eukaryotes are likely evolved from ingested ___________________________. -thylakoids. -photosynthetic eukaryotes. -chlorophyll. -cyanobacteria.
cyanobacteria.
Membrane-bound proteins involved in the electron transport chain that contain a heme group are termed _____________________. ubiquinones. ATP synthases. flavoproteins. cytochromes.
cytochromes
The active site of a chlorophyll molecule is structurally most similar to what?
cytochromes
The Krebs cycle occurs in the _________ in bacteria.
cytoplasm
In translation, the site through with tRNA molecules leave a ribosome is called a. A site b. X site c. P site d. E site
d. E site
Which of the following items functions most like an autoclave? a. a boiling pan b. an incinerator c. a microwave oven d. a pressure cooker
d. a pressure cooker
Which of the following disinfectants contains alcohol? a. an iodophor b. a quat c. formalin d. a tincture of bromine
d. a tincture of bromine
A nucleotide is composed of a. a five-carbon sugar b. phosphate c. a nitrogenous base d. all of the above
d. all of the above
Before mutations can affect a population permanently, they must be a. lasting b. inheritable c. beneficial d. all of the above
d. all of the above
Nucleotides used in the replication of DNA and stabilizes it? a. carry energy b. are found in four forms, each with deoxyribose sugar, a phosphate, and a base c. are present in cells as triphosphate nucleotides d. all of the above
d. all of the above
The microbial death rate is used to measure a. the efficiency of a detergent b. the efficiency of a antiseptic c. the efficiency of sanitization techniques d. all of the above
d. all of the above
Which of the following statements is true concerning the selection of an antimicrobial agent? a. an ideal antimicrobial is stable during storage b. an ideal antimicrobial agent is fast acting c. ideal microbial agens do not exist d. all of the above
d. all of the above
Which of the following viruses can be latent? a. HIV b. chickenpox virus c. herpesviruses d. all of the above
d. all of the above
Which of the following adjectives best describes a surgical procedure that is free of microbial contaminants? a. disinfected b. sanitized c. degermed d. aseptic
d. aseptic
Cells that have the ability to take up DNA from their environments are said to be a. Hfr cells b. transposing c. genomic d. competent
d. competent
Which antimicrobial chemical has been used to sterilize spacecraft? a. phenol b. alcohol c. heavy metal d. ethylene oxide
d. ethylene oxide
A plasmid is a. a molecule of RNA found in bacterial cells b. distinguished from a chromosome by being circular. c. a structure in bacterial cells formed from plasma membrane. d. extrachromosomal DNA
d. extrachromosomal DNA
Which of the following substances would most effectively inhibit anaerobes? a. phenol b. silver c. ethanol d. hydrogen peroxide
d. hydrogen peroxide
A company that manufactures an antimicrobial cleaner for kitchen counters claims that its product is effective when used in a 50% water solution. By what means might scientists best verify this statement? a. disk-diffusion test b. phenol coefficient c. filter paper test d. in-use test
d. in-use test
Which of the following is not a criterion for specific family classification of viruses? a. the type of nucleic acid present b. envelope structure c. capsid type d. lipid composition
d. lipid composition
12. Which of the following methods is best for counting fecal bacteria from a stream to determine the safety of the water for drinking? a. dry weight b. turbidity c. viable plate counts d. membrane filtration
d. membrane filtration
Which of the following method is best for counting fecal bacteria from a stream to determine the safety of the water for drinking? a. dry weight b. turbidity c. viable plate counts d. membrane filtration
d. membrane filtration
7. Organisms that preferentially may thrive in icy waters are described as a. barophiles. b. thermophiles. c. mesophiles. d. psychrophiles.
d. psychrophiles
Organisms that perferentially may thrive in icy waters are described are a. barophiles b. thermophiles c. mesophiles d. psychrophiles
d. psychrophiles
Which of the following terms best describes that disinfecting of cafeteria plates? a. pasteurization b. antisepsis c. sterilization d. sanitation
d. sanitation
Which of the following are called "jumping genes"? a. Hfr cells b. transducing phages c. palindromic sequences d. transposons
d. transposons
Carbon dioxide is produced whenever _____________ occurs in cellular respiration.
decarboxylation
What occurs at the transition step? -formation of ATP and NADH -decarboxylation of pyruvic acid to acetyl CoA -formation of GTP from GDP and inorganic phosphate -conversion of citric acid to isocitric acid
decarboxylation of pyruvic acid to acetyl CoA
amount of time required to reduce viability tenfold
decimal reduction time
treatment that renders an object or inanimate surface safe to handle
decontamination
Before producing the Human growth hormone (hGH), where did this enzyme was recovered?
derived from pituitary of human cadavers
Mutants
descendents of a cell that does not successfully repair a Mutation
Pour plate is based on_of bacteria
dilution
Microbiologists use _methods to estimate microorganisms
direct and indirect
an antimicrobial agent used only on inanimate objects, i.e. lysol or bleach
disinfectant
Antiseptics are frequently_
disinfectants whose strength has been reduced to make them safe for living tissues
Unlike sterilization,_does not guarantee that all pathogens are eliminated
disinfection
directly targets the removal of all pathogens, not necessarily all microorganisms
disinfection
Ions
disrupt Hydrogen bonding, Oxidize double covalent bonds, and create Hydroxide Ions; Hydroxide ions denature other molecules (DNA)
Why is alcohol a good degermer?
dissolves lipids and lifts bacteria off of skin, disrupts cytoplasmic membrane by dehydration
Colonies have_ that can help identify and classify microbe.
distinctive characteristics
after incubation, the various types of organism present are_
distinguished from one another by differences in colonial characteristics.
How do microwaves kill cells?
do not penetrate cells but kill indirectly through heat
aerotolerant anaerobes
do not use Aerobic Metabolism, but do have some enzymes that detoxify oxygen's poisonous forms, so can grow in its presence
Anaerobes
do not use aerobic metabolism
DNA
double stranded alpha helix, sugars and phospates make backbone which are covalently bonded to eachother, bases are H-bonded together A-T G-C, Sides of the ladder are the sugars and phosphates, the rungs are the pairs of nitrogenous bases (ATGC)
Thousands
due to the size of Eukaryotic Chromosomes, how many replication origins are there in Eukaryotic DNA Replication?
mRNA, major rRNA, tRNA and smaller rRNA
each of the first three types of RNA Polymerases are used to transcribe different types of RNA. what is each one used for? (separate them by commas)
temperature range
each organism survives over a temperature range, within which its growth and metabolism are supported
Peracetic Acid
effective Sporocide used to sterilize equipment--since it's not adversely affected by organic contaminants and leaves no toxic residue
Phenol and Phenolics
effective in the presence of organic matter and remain active for a prolonged time
Ionizing radiation
eject electrons from atoms to create Ions
NAD+, FAD, and NADP+ are all examples of __________. electron carriers enzymes cytochromes precursor metabolites
electron carriers
All of the following processes are ways that a cell can use a proton gradient EXCEPT __________. -active transport -flagellar motion -electron transport -ATP production
electron transport
trace elements
elements that are require in very small amounts
hyperglycemia
elevated blood glucose levels
low level germacides
eliminate vegetative bacteria, fungi, protozoa and some viruses (disinfect items that only contact the skin of patients, furniture electrodes)
What is the best definition of sterilization? A. removal of unwanted microorganisms B. removal of viruses C. elimination of bacteria D. elimination of all microorganisms
elimination of all microorganisms
Because building anything requires energy, anabolic pathways are __________,that is, they require more energy than they release.
endergonic
According to the eight statements that guide the metabolic processes, ______________ is stored in the chemical bonds of adenosine triphosphate (ATP).
energy
What is the term given for the energy required to convert reactants into products in a chemical reaction? -chemical potential energy -enzymes -energy of activation -electron configuration
energy of activation
Aseptic
environment or procedure free of pathogens
Gyrase
enzyme in Prokaryotic cells that further folds the already folded loops of chromosomal DNA and supercoils the Chromosome into a compact mass
DNA Polymerase III
enzyme that comes in (after the DNA strand has been split into a replication fork) that binds to the Parent Strand and synthesizes a Daughter Strand by adding DNA nucleotides (1 at a time) to the 3' end of the molecule; synthesis proceeding in only one direction- from 5' to 3' end
Transposase
enzyme that cuts and inserts Transposons in the DNA molecule
DNA Polymerase I
enzyme that replaces RNA Primer with DNA
Topoisomerases
enzymes that remove supercoils in DNA molecules that form ahead of the replication fork due to the unzipping action of Helicases, which creates tension in DNA that could stop replication
RNA Polymerases
enzymes that synthesize RNA
Nonionizing radiation
excites electrons and causes them to make new covalent bonds, which affects the 3-D structure of Proteins and Nucleic acids
When catabolic pathways break down large molecules they release energy. Therefore catabolic pathways are __________.
exergonic
With each repetition of the cycle, the number of DNA molecules increases _. Explain how get the number of DNA molecules in PCR
exponentially Multiply the resultant number of DNA molecules by 2 in every cycle (2^n)
Which of the following is NOT an advantage conferred on microbial cells by a biofilm? -protection from environmental stresses --formation of microenvironments -ability to stick to a substrate -extension of the microbial growth phase
extension of the microbial growth phase
-uses oxygen when present, but can also grow in the absence of oxygen
facultative anaerobe
A reducing medium is most often used for growing fastidious bacteria that have very specific nutritional requirements. True False
false
ATP is made by substrate-level phosphorylation only during glycolysis. True False
false
An amphibolic reaction is one that is irreversible. True False
false
Bacterial growth curves are plotted on graphs that have a logarithmic scale on both the x- and y-axes. True False
false
Cells that divide by binary fission in different planes produce a chain formation of cells. True False
false
Chloroplast structure features thylakoids arranged in stacks called stroma. True False
false
Direct methods of measuring microbial growth are more accurate than indirect methods. True False
false
Fermentation results in the production of carbon dioxide and water from pyruvic acid. True False
false
High temperatures break the covalent bonds that give enzymes their characteristic shapes, thereby denaturing them. True False
false
In feedback inhibition pathways, the end-product of the pathway is usually an inhibitor of the last enzyme in the pathway. True False
false
Refrigeration kills all bacterial cells except psychrophiles. True False
false
The MPN (most probable number) method of measuring microbial growth is one of the easiest and quickest methods. -true -false
false
The carrier molecules in electron transport chains are all integral membrane proteins. True False
false
The first compound formed in the Krebs cycle is oxaloacetic acid. True False
false
The quantity n2 represents the number of cells that arise from a cell that reproduces by binary fission. True False
false
When performing serial dilutions and viable plate counts, the concentration of microorganisms is usually expressed as number of bacteria per milliliter. True False
false (*The concentration is expressed in colony-forming units, or CFU, per milliliter.)
Most bacterial cells divide using a process called binary fusion. True False
false (Fusion means to join together. Bacterial cells divide using binary fission, not fusion.)
Beta-oxidation is a method of catabolizing what molecules?
fatty acids
Beta-oxidation is a method of catabolizing which of the following molecules? fatty acids amino acids glycerol glucose
fatty acids
Ex of facultative anaerobes?
few yeast and numerous prokaryotes
9. Microbes that reduce N2 to NH3 engage in nitrogen _____.
fixation
Microbes that reduce N2 to NH3 engage in nitrogen __________.
fixation
Microbes that reduce N2 to NH3 engage in nitrogen ____________.
fixation
Proton gradients can be used for active transport, ________ _________, and ATP production.
flagellar motion
What are the four classes of carrier molecules in electron transport systems?
flavoproteins, ubiquinones, metal-containing proteins,cytochromes
Electron beams
form of radiation effective at killing, but do not penetrate well
Gamma Rays
form of radiation that penetrate well, but require hours to kill microbes
X Rays
form of radiation that require too much time to be practical for growth control
Okazaki Fragments
formed as a result of synthesis of the lagging strand since replication goes in the direction away from the replication fork
Insertions and deletions in the genetic code are also called __________ mutations.
frameshift
Insertions are deletions in the genetic code are also called ___________ mutations.
frameshift
sterile
free of any microbial contaminants
where restriction enzymes are isolated?
from bacterial cells
How do the protons flow in an electron transport system in a prokaryote? -from regions of high concentration to low concentrations along a mitochondrial membrane -from regions of high concentration to low concentrations along a cell membrane -from regions of low concentration to high concentrations along a cell membrane -from regions of low concentration to high concentrations along a mitochondrial membrane
from regions of high concentration to low concentrations along a cell membrane
A chemical that reduces spoilage in fruit by destroying fungi, but does not appear to affect other microbes, would be called a __________. A. fungicidal agent B. fungistatic agent C. sterilant D. bactericidal agent
fungicidal agent
an agent that kills fungi
fungicidal agent
an agent that inhibits fungal growth
fungistatic agent
a peptide that blocks the fusion of viral and target cytoplasmic membranes
fusion inhibitor
prevent viruses from successfully fusing with the host cell
fusion inhibitors
What is ethylene oxide?
gas used to sterilize plastic petri dishes and other plastic supplies
The primary role of electron transport chains in many organisms is to ___________________. -pump hydrogen ions outside of a membrane. -transfer electrons along a cell membrane. -generate usable energy in the form of ATP. -allow water to flow from regions of high concentrations to low concentrations
generate usable energy in the form of ATP.
Structural Genes
genes on DNA that carry information for synthesis of specific proteins (enzymes or cell structures)
The creation of injections for diabetes is an example of the use of _
genetic engineering
Recombinant DNA technique provides a simpler and universal methods for_
genetic mapping
cell counter
glass slide composed of an etched grid positioned beneath a glass cover slip -It has 25 large squares which are divided into 16 small squares
Histones
globular proteins that support DNA
Where does the energy come from to make ATP during glycolysis? -NADH -glucose -pyruvic acid -water
glucose
What molecule is fed directly into the energy conservation stage of glycolysis? -NAD+ -glyceraldehyde 3-phosphate -pyruvic acid -dihydroxyacetone phosphate (DHAP) -glucose -1,3-bisphosphoglycerate acid
glyceraldehyde 3-phosphate
Bacteria can synthesize glycerol by reversing which pathway? -beta-oxidation -glycolysis -Krebs cycle -gluconeogenesis
glycolysis
In eukaryotic cells, all of the following processes occur in the mitochondrion EXCEPT __________. electron transport glycolysis beta-oxidation the Krebs cycle
glycolysis
Select the correct sequence of steps as energy is extracted from glucose during cellular respiration. -glycolysis → citric acid cycle → acetyl CoA → electron transport chain -glycolysis → acetyl CoA → citric acid cycle → electron transport chain -acetyl CoA → citric acid cycle → electron transport chain → glycolysis -electron transport chain → citric acid cycle → glycolysis → acetyl CoA -citric acid cycle → electron transport chain → glycolysis → acetyl CoA
glycolysis → acetyl CoA → citric acid cycle → electron transport chain - Glycolysis produces pyruvic acid, which enters the mitochondrion. There, it is converted to acetyl CoA, which enters the citric acid cycle. In bacteria, pyruvic acid is converted to acetyl CoA in the cytoplasm. Electron carriers bring electrons from the first three steps to the electron transport chain, and ATP is made.
Glycerol is degraded via the __________ pathway.
glycolytic
Standards of sanitization vary among_
governmental jurisdictions
Thylakoid stacks in the chloroplast are called ________, whereas the space between the thylakoid membrane and the outer membrane of the chloroplast is called the _________.
grana; stroma
polyribosome
group of ribosomes that form the same polypeptide from the same mRNA
anticodon
group of three bases on a tRNA molecule that are complementary to an mRNA codon
Psychrophiles
grow best at about 15 degrees celcius; can grow below 0 degrees celcius, but not much above 20 degrees celcius, cause food spoilage
a chemical agent that is related to and blocks the uptake of a growth factor
growth factor analog
4. ______ are small organic molecules that are required in minute amounts for metabolism.
growth factors
Organic molecules that prokaryotic organisms need, but cannot synthesize by themselves, are called __________.
growth factors
_________ are small organic molecules that are required in minute amounts for metabolism.
growth factors
_____________ are small organic molecules that are required in minute amounts for metabolism.
growth factors
Genetic samples for genetic fingerprinting can come from_
hair blood
7. Obligate _____ exist in salt ponds because of their ability to withstand high osmotic pressure.
halophiles
Bacteria that grow in high salt concentrations are termed __________. -mesophiles -psychrophiles -halophiles -barophiles
halophiles
Obligate ___________ exist in salt ponds because of their ability to withstand high osmotic pressure.
halophiles
Obligate ____________ exist in salt ponds because of their ability to withstand high osmotic pressure.
halophiles
DNA replication in prokaryotes
happens before binary fission, proceeds from a single origin.
sterilization indicates only the eradication of_
harmful microorganisms and viruses
Escherichia coli
have Plasmids with genes for certain toxins that cause diarrhea (Virulence Plasmids)
How does heat kill cells?
heat kills orgs because it denatures proteins
Enzymes may be denatured by physical and chemical factors such as _________and_________. Denaturation may be reversible or permanent.
heat;ph
A site
holds the tRNA carrying the next amino acid to be added to the chain A = amino acid
-the combination of both apoenzyme and its cofactors
holoenzyme
Sodium Hypochlorite
household chlorine bleach (example of acidic conditions enhancing antimicrobial effects of a chemical disinfectant)
three
how many Binding Sites do Ribosomes have?
four
how many DNA Polymerases do Eukaryotes use in DNA replication?
1
how many copies of each chromosome do prokaryotic cells have?
four
how many types of RNA Polymerases are used in Eukaryotes? (just like how many DNA Polymerases are used in Eukaryotes)
What is the most common chemical element in the cells?
hydrogen
Which of the following is NOT a toxic form of oxygen? peroxide anions hydroxide ion superoxide radicals singlet oxygen
hydroxide ion
In which of the following solutions would a cell become crenated? -hypertonic solutions -hypotonic solutions -acidic solutions -isotonic solutions
hypertonic solutions (ph alone does not affect osmosis)
Triphosphate ribonucleotides
in Elongation of RNA Transcription, these align themselves opposite their Complementary Bases in the open DNA Nucleotide Strand
RNA Polymerase
in Elongation of RNA Transcription, this uses the energy from terminal Phosphate Groups of Triphosphate Ribonucleotides to join RNA Nucleotides together as it moves along DNA
where are macrophiles found within a Thioglycollate tube?
in the middle
Primase
in the synthesis of the Leading strand and Lagging strand, this enzyme synthesizes RNA Primer
Where would you find the highest concentration of hydrogen ions? -in the cytoplasm -in the thylakoid space -outside the cell -in the thylakoid membrane -in the cytochromes
in the thylakoid space
Bacillus anthracis
in the virulence plasma of _________ ________ code for its neurotoxin
Selective media differentiate bacteria by_
inability to grow within the media
In general, __________ operons are inactive until the substrate of their genes' polypeptides is present.
inducible
the reduction of microbial growth because of a decrease in the number of organisms present or alterations in the microbial environment
inhibition
The three steps in RNA transcription are ____________, ____________ and ____________.
initiation of transcription, elongation of the RNA transcript, termination of transcription
Lyophilization
instant freezing in liquid nitrogen; then exposure to vacuum for water removal-- used for long term preservation of microbial cultures
a cytokine protein produced by virus-infected cells that induces signal transduction in nearby cells, resulting in transcription of antiviral genes and expression of antiviral proteins, stimulates antiviral proteins in uninfected cells
interferon
Scientists can synthesize subunits of vaccines by_
introducing genes for a pathogen's polypeptides into vectors.
Redox reactions ___________________________. -involve the passing of electrons from one molecule to another. -are involved only in the electron transport chain. -involve both of the above. -involve neither of the above.
involve the passing of electrons from one molecule to another.
In photosynthetic bacteria, the light-dependent reaction __________. -involves an electron transport chain -occurs within the chloroplast -uses ATP and NADH -is called the Calvin-Benson cycle
involves an electron transport chain
Nitrogen fixation __________. involves reduction of nitrogen gas to ammonia -is the oxidation of nitrogen gas to from amino acids -is the process that incorporates nitrogen into nucleotides -is carried out by all bacteria
involves reduction of nitrogen gas to ammonia
used to disinfect water
iodine, ozone
How do Gamma/X-rays kill cells? What is it used for?
ionizing radiation, break DNA in cells used with foods and fruits/spices as a way to decontaminate
A chemostat __________. -is used to count bacteria -is a device used to culture obligate anaerobes -is a device that maintains a bacterial culture in a particular phase of growth -is a method used to isolate bacteria into pure culture
is a device that maintains a bacterial culture in a particular phase of growth
Gel electrophoresis
is a technique for separating molecules (including fragments of nucleic acids) by size, shape, and electrical charge.
An aerotolerant anaerobe is a bacterium that ...............
is able to detoxify oxygen, but does not use it for its metabolism
Thermogenin _______________________.(may be more than one answer) -acts in a manner similar to oxygen deprivation. -is found in certain mammalian fat cells. -is an example of a protein uncoupler. -is found in many bacterial cells.
is an example of a protein uncoupler. is found in certain mammalian fat cells.
Embden-Meyerhof pathway ______________. (can be more than one answer) -is another name for glycolysis. -is another name for the preparatory stage. -is named after its discoverers. -is another name for the energy-conservation stage.
is another name for glycolysis. is named after its discoverers
The electron transport chain __________. -produces less ATP than in glycolysis -is located in the cytoplasmic membrane in bacteria -is the site of fermentation -is the location where the Krebs cycle occurs
is located in the cytoplasmic membrane in bacteria
The activation energy of a chemical reaction __________. can be achieved by lowering the temperature of a reaction is the same for all chemical reactions is eliminated in the presence of an enzyme plus a coenzyme is lower in the presence of an enzyme
is lower in the presence of an enzyme
Chemiosmosis ____________________________. -occurs along the cell membrane of eukaryotes. -is the process of using a proton gradient to generate ATP. -is the name given to membrane-bound proteins involved in electron transport. -is the process of using an electron gradient to produce ATP.
is the process of using a proton gradient to generate ATP
Beta-oxidation __________. -is a process bacteria can use to break down proteins -is the name given to the process that occurs in the electron transport chain -is the process used by bacteria to catabolize amino acids -is the process used by many bacteria to catabolize fatty acids
is the process used by many bacteria to catabolize fatty acids
Genomics
is the sequencing, analysis, and comparison of genomes
The active site ____________________. -is another term for "substrate." -is where the reactants bind. -is the term for an enzyme that has returned to its original state after a chemical reaction. -is the compound that an enzyme reacts with during the chemical reaction.
is where the reactants bind.
Which of the following is NOT a possible form of regulation of metabolism in bacteria? -cells that use inhibitory and excitatory allosteric sites on enzymes to control activity -feedback inhibition that slows or stops the anabolic pathway when the product is abundant -synthesis of enzymes for the catabolism of substrate when the substrate is present -isolating enzymes within membrane-bound regions, such as lysosomes
isolating enzymes within membrane-bound regions, such as lysosomes
While pure cultures of bacteria may be grown in a chemostat, it is not used for _________ of bacteria.
isolation
The most effective single drug used for control and treatment of tuberculosis
isoniazid
All of the following are drawbacks to the use of spectrophotometry in estimating microbial growth EXCEPT __________. -it cannot distinguish between live and dead cells -it kills the organisms as they are being counted -it cannot be used if there are less than one million cells per milliliter -it will underestimate the true number of cells if they are not uniformly in suspension
it kills the organisms as they are being counted
When a molecule is reduced, ___________________. -it has lost an electron. -it has become smaller. -its electrical charge has been reduced by the addition of an electron. -it is called the electron donor.
its electrical charge has been reduced by the addition of an electron.
Stabilizing proteins
keep DNA strands from rejoining after being split by DNA Helicase into a replication fork
Intermediate-level germicides
kill Fungal Spores, Protozoan cysts, viruses and pathogenic bacteria
High-level germacides
kill all pathogens including bacterial endospores (invasive health equipment, catheters, implants, heart-lung machines)
High-level germicides
kill all pathogens, including Endospores
Intermediate level germacides
kill fungal spores, protozoan cysts, viruses, and pathogenic bacteria, but not bacterial endospores (disinfect instruments that come in contact with mucous membrances but are non invasive, endoscopes)
Low-level germicides
kill vegetative bacteria, Fungi, Protozoa, and some Viruses
What are the disadvantages of broad spectrum antibiotics?
kills normal flora, end up with diarrhea, allows patient to become susceptible to opportunistic infections like thrush and yeast from Candida albicans
what are the ethical consequences of medical diagnosis?
know beforehand what is wrong with someone (human)
ATP is made by substrate-level phosphorylation NOT only during glycolysis, but A small amount of ATP is also made by substrate-level phosphorylation during the ________ ________.
krebs cycle
example of aerotolerant
lactobacilli
Which growth phase occurs first, after placing an inoculum into a nutrient broth? -death phase -stationary phase -lag phase -log phase
lag phase
obligate anaerobes must derive the energy they need for metabolism from_
light
Metabolic processes are guided by eight elementary statements. Statement 2: Metabolism requires energy from what two things?
light; or from the catabolism (breaking down) of acquired nutrients.
Recombine (in recombinant DNA technology)
linking two pieces of DNA that were not together before creating a new DNA
What is a growth factor analog? Give an example of one
look similar in structure to what the pathogen needs but when it gets the analog, leads to cell death. Example: sulfa drugs and isoniazid
Transformation
loose DNA floats to entry sites on closely related bacteria donor DNA spliced into recipient's chromosome all progeny will show new DNA's base pairs in their chromosome
Euchromatin
loosely-packed chromatin fibers where genes are active
Which of the following is NOT a method for isolating bacteria in a pure culture? -streak-plate method -serial dilutions of broth media -lyophilization -pour-plate technique
lyophilization
What is the function or mRNA?
mRNA carries genetic information from chromosomes to ribosomes
Riboswitch
mRNA molecule that changes its shape in response to a change in temperature or concentration of a nutrient and thus blocks Ribosomes and Translation of the Polypeptides they encode
carbon dioxide incubators
machines that electronically monitor and control CO2 levels, provide atmosphere that mimic environments of the intestinal tract, respiratory tract, and other body tissues
Erythromycin, contain lactone rings bonded to sugars, borad spectrum antibiotic that targets the bacterial ribosome
macrolides
According to the eight statements that guide the metabolic processes, cells use enzymes and additional energy from ATP to anabolically link building blocks together to form ________________ in polymerization reactions.
macromolecules
Anabolic pathways are functionally the opposite of catabolic pathways in that they synthesize ____________ and _________ __________.
macromolecules;cellular structures
_of prokaryotes have never been grown in culture medium
majority
What effect does oxygen deprivation have on an aerobic cell? -keeps cytochrome a3 in the reduced state -an increase in the amount of heat generated by the ETC -increases the amount of thermogenin -makes the cell unable to maintain a proton gradient
makes the cell unable to maintain a proton gradient
rRNA
makes up ribosomes
Regulation of Transcription
means of regulating protein synthesis that involves Prokaryotic Operons (not present in Eukaryotes)
Osmolarity
measure of the number of solute particles (Dissolved stuff) dissolved in the solvent (water for example)
pH
measurement of the concentration of hydrogen ions in a solution
Membrane filters are used to sterilize what?
media and supplements like antibiotic solutions
human pathogens are in which category of temperature?
mesophile because they can stand 37 degree Celsius of the human body
Vibrio sp.
mesophiles, halophile, alkalinophile, gram negative; curved rod, comma, cholera; bacterium with 2 chromosomes
mRNA
messenger RNA; type of RNA that carries instructions from DNA in the nucleus to the ribosome
All of these statements are correct descriptions of bacterial metabolism EXCEPT __________. -if two energy sources are available, cells catabolize the more energy efficient of the two -feedback inhibition can be used to stop anabolic pathways when the product is in abundance -metabolic processes can be isolated within certain parts of the cell, such as lysosomes -cells often synthesize enzymes for a particular catabolic process only if the substrate for that process is available
metabolic processes can be isolated within certain parts of the cell, such as lysosomes
-all of the chemical in an organism
metabolism
what is a major characteristic of all living things?
metabolism
What is MRSA
methicillin resistant Staph. aureus
Helicobacter pylori
microaerophile, acidophile, primary cause of gastric and duodenal ulcers, gastritis Patients with Helicobacter infections have higher risk of stomach cancer Produces urease (NH3 generation).
-These are aerobes that require an environment with 2-10% oxygen.
microaerophiles
Microbial metabolism-the collection of controlled biochemical reactions that takesplace within the __________.
microbe
Neutrophiles
microbes that grow best in a narrow range around neutral pH (6.5-7.5); includes most bacteria an protozoa
Alkalinophiles
microbes that live in alkaline soils and water up to pH 11.5
Common fermentation tests include pH indicators, which change colors as the pH of the test changes due to__________fermentation.
microbial
-The collection of controlled biochemical reactions that takes place within the microbe.
microbial metabolism
Anticodon
middle loop at the other end of the tRNA molecule that contains a nucleotide triplet complementary to the specific mRNA Codon for the Amino Acid the tRNA carries
Nucleotide Analogs
mimic the shape of ATGC or U, make potent antiviral or anticancer drugs.
5. The lowest temperature at which a microbe continues to metabolize is called its
minimum growth temperature
The lowest temperature at which a microbe continues to metabolize is called its _____________.
minimum growth temperature
the minimum concentration of a substance necessary to prevent microbial growth
minimum inhibitory concentration (MIC)
The lowest temperature at which a microbe continues to metabolize is called its _____________.
minmum growth temperature
In what organelle of a eukaryote would you find acetyl CoA formation, the citric acid cycle, and the electron transport chain? -Golgi apparatus -nucleus -mitochondrion -lysosome -chloroplast
mitochondrion
transformation
modification of a cell or bacterium by the uptake and incorporation of exogenous DNA
Aspergillus flavus
mold, airborne, chemical mutagen, best known aflatoxin producer-often found in grains and peanuts
tRNA
molecule that brings Amino Acids to Ribosomes and consists of a chain of RNA Nucleotides in the shape of a bent "cloverleaf"
mRNA
molecule that carries a message of DNA (as a sequence of RNA Nucleotides) to Ribosomes, and serves as a template for Polypeptide Synthesis
nucleotides
molecules composed of 1)Pentose (5-carbon sugar) - Deoxyribose in DNA; Ribose in RNA 2) Phosphate group (PO4-3) 3) Nitrogenous (nitrogen-containing) Base
RNA
mostly single stranded, can be globular, pars are A-U and G-C, all types are transcribed from DNA
Mutagens, restriction enzymes, vectors, and the other tools of recombinant DNA technology are used in a variety of techniques to _
multiply, identify, manipulate, isolate, map, and sequence the nucleotides of genes.
The media are not_
mutually exclusive categories, which means in some cases a given medium can belong to more than one category
During the 20th century, scientists industrialized the _to produce products
natural metabolic reactions of bacteria
mineral ions
neede for cofactors of enzymes
Most bacteria and protozoa, including most pathogens, grow best in a narrow range around a _pH
neutral (6.7-7.5)
Catalase
neutralizes, but is not useful for treating open wounds
Lagging Strand
new DNA strand in which synthesis moves away from the Replication Fork, and occurs in short segments which are later joined together
Leading Strand
new DNA strand in which synthesis proceeds toward the Replication Fork, and is continuous
Which of the following would be a final electron acceptor for anaerobic respiration?(possibly more than one answer) sulfate ion nitrate ion water oxygen ATP
nitrate ion sulfate ion
When organisms cannot use oxygen as an electron acceptor in cellular respiration, they often use ________or________ instead.
nitrates or sulfates
3. All cells recycle the essential element ____ from amino acids and nucleotides.
nitrogen
All cells recycle the essential element ____________ from amino acids and nucleotides.
nitrogen
All cells recycle the essential element _____________ from amino acids and nucleotides.
nitrogen
What is another essential element?
nitrogen (found in amino acids)
Guanine, Cytosine, Adenine
nitrogenous bases common to both DNA and RNA nucleotides
Introns
noncoding nucleotide sequences
-attach to an allosteric site on an enzyme, altering the active site so that it is no longer functional.
noncompetitive inhibitors
Denaturation of proteins occurs as high temperatures break ___________ bonds such as hydrogen bonds.
noncovalent
nonnucleoside analog used to inhibit viral reverse transcriptase
nonnucleoside reverse transcriptase inhibitor (NNRTI)
What type of drugs are used to treat viral infections?
nucleic acid base analogs (ex. AZT), protease inhibitors, fusion inhibitors, adamantanes, neuraminidase inhibitors, interferons
nucleoside analog used to inhibit viral reverse transcriptase
nucleoside reverse transcriptase inhibitor (NRTI)
frameshift mutations
nucleotide triplets are displaced creating new sequences of codons that result in vastly altered polypeptide sequences insertion deletion
Folic acid is a precursor molecule necessary for the synthesis of which of the following? nucleotides cholesterol amino acids glycerol
nucleotides
According to the eight statements that guide the metabolic processes, every cell acquires what chemicals, that are necessary for metabolism?
nutrients
Metabolic processes are guided by eight elementary statements. Statement 1: Every cells acquires _____________, which are the chemicals necessary for metabolism.
nutrients
Only__________ __________require high salt concentrations in order to grow.
obligate halophiles
The term lithotroph is used to describe organisms that __________. -require only small amounts of oxygen to survive -live in extremely cold climates -require high concentrations of CO2 for their growth -obtain their electrons or hydrogen ions from an inorganic source
obtain their electrons or hydrogen ions from an inorganic source
The Calvin-Benson cycle __________. -produces NADH for use in the electron transport chain -produces CO2, glucose, and ATP -utilizes NADH and ATP as energy sources -occurs in the cytoplasm of photosynthetic bacteria
occurs in the cytoplasm of photosynthetic bacteria
Rho-Dependent Termination
occurs when a termination PROTEIN binds to the RNA sequence near the end of the transcript and moves toward the 3' end, forcing the RNA Polymerase and DNA strand apart
recombinants
offspring whose phenotype differs from that of the parents
Eukaryotic cells
often have two copies of each chromosome (Diploid cells)
Substitutions
one BASE replaced by another
Point Mutation
one involving a SINGLE nucleotide base pair
P site
one of a ribosome's three binding sites for tRNA during translation. It holds the tRNA carrying the growing polypeptide chain. P= polypeptide
Frameshift Mutation
one resulting in one or two Base Insertion or Deletion that causes a shift in the Reading Frame (3 Base Sequence) which usually changes all subsequent Codons after Insertion or Deletion, producing a nonfunctional protein
Missense Mutation
one that causes a single AMINO ACID to be substituted for another in the protein Synthesized
Nonsense Mutation
one that changes an Amino Acid-coding Codon into a Stop Codon, which prematurely terminates the synthesis of the protein and renders it nonfunctional
Extranuclear DNA of Eukaryotes
only codes for about 5% of RNA and Proteins
Operon
operational gene unit that regulates Gene expression by controlling Transcription (mRNA synthesis) and therefore regulates protein synthesis
broths
organism can be grown in a liquid media
Obligate aerobe
organism that requires a constant supply of oxygen in order to live
How organism in a laboratory environment live very differently than organisms in nature?
organisms in nature live association with other individuals of their own and different species
Symbiotic relationship
organisms live in such close nutritional or physical contact that they become interdependent, such that the members rarely live outside the relationship
Vertical Gene Transfer
organisms replicate their Genomes and provide copies to their DESCENDENTS--Passing of genes to the NEXT GENERATION
capnophiles
organisms that grow better at relatively high concentration of carbon dioxide in addition to low oxygen levels
6. Cells that shrink in hypertonic solutions such as saltwater are responding to _____ pressure.
osmotic
Cells that shrink in hypertonic solutions such as saltwater are responding to __________ pressure.
osmotic
Antimicrobials
other than for the treatment of diseases, some of these are used for antimicrobial control outside the body
Why do bacteria become resistant to antibiotics?
overuse of antibiotics, not taking complete prescriptions
NADH is converted to ATP in a process known as ___________________. oxidative phosphorylation reduction oxidation decarboxylation
oxidative phosphorylation
How does chlorine work?
oxidizing agent
How does hydrogen peroxide work?
oxidizing agent
In aerobic respiration, the final electron acceptor is __________. -glucose -oxygen -ATP -ethanol
oxygen
What is the final electron acceptor in the electron transport chain of aerobic bacteria? water FADH2 oxygen FMNH2 NADH
oxygen
Which of the following does NOT affect the activity of an enzyme? substrate concentration oxygen concentration pH temperature
oxygen concentration
the thioglicollate growth medium has a _
oxygen gradient from the top to the bottom
Microbial fermentation can be detected in laboratory identification schemes by observing a change in __________. glucose levels oxygen levels temperature pH
pH
Which of the following could be an optimal pH for the growth of an acidophile? pH 11.0 pH 3.0 pH 7.0 pH 8.5
pH 3.0
Sigma Factor
part of RNA Polymer that recognizes the Promoter
reduction of the microbial load in heat-sensitive liquids to kill disease producing microorganisms and reduce the number of spoilage microorganisms; does not kill all organisms. Used on materials that are heat sensitive, like milk
pasteurization
Disinfection term is used primarily in relation to_
pathogens
Medical laboratory personnel must also grow_
pathogens as an step in diagnosis of many diseases
Metabolism, which is all of the chemical reactions in an organism, can be divided into two major classes of reactions: catabolism and anabolism. A series of such reactions is called a _____________.
pathway
DNA fingerprinting can be to generate unique_
patterns of DNA separated on gel.
What was the first antibiotic produced by humans?
penicillin
a class of antibiotics that inhibit bacterial cell wall synthesis, characterized by a B-lactam ring
penicillins
NADPH is produced within the _________ _________ __________, as well as during photosynthesis, not during glycolysis
pentose phosphate pathway,
What does make hydrogen perioxide an antimicrobial agent?
perioxide anion
Enzymatic reactions reach a saturation point when the active sites of all enzymes present are occupied by substrate molecules. This ___________ is a limiting factor for all enzymatic reactions.
phenomenon
Ligase unites the _of the pieces of DNA cut by the restriction enzyme
phosphate backbones
Which of these would NOT be considered a growth factor for bacteria? phosphorus amino acids purines and pyrimidines vitamins
phosphorus
Organisms that use light as their energy source and carbon dioxide as their carbon source are considered __________.
photoautotrophs
A cell that uses an organic carbon source and obtains energy from light would be called a __________.
photoheterotroph
Which of the following processes is considered solely anabolic? -pentose phosphate pathway -fermentation -Krebs cycle -photosynthesis -oxidative phosphorylation
photosynthesis
The source of electrons is ________________________. -photosystem I. -carbon dioxide. -oxygen. -ATP. -NADPH.
photosystem I.
Phenotype
physical features and functional traits of an organism which is determined by its Genotype
dissinfectant
physical or chemical agent used to inhibit or destroy microorganisms on inanimate objects
new structural class of antibiotic, broad-spectum, effective against MRSA and vancomycin-resistant enterococci
platensimycin
types of gene mutations
point mutations frameshift mutations
Metabolic processes are guided by eight elementary statements. Statement 6: Cells use enzymes and additional energy from ATP to anabolically link building blocks together to form macromolecules in __________________ reactions.
polymerization
polypeptides
polymers of amino acids
Detergents
positively charged Organic Surfactants, and more soluble in water than soaps
-Any of 12 molecules typically generated by metabolic pathway and essential to the synthesis of organic macromolecules in cells.
precurser metabolite
According to the eight statements that guide the metabolic processes, using enzymes, cells catabolize nutrient molecules to form elementary building blocks called _________ __________.
precurser metabolites
The pentose phosphate and Entner-Doudoroff pathways are alternative means for the catabolism of glucose that yield fewer ATP molecules than does glycolysis. What do these two pathways produce that glycolysis does not?
precurser metabolites
Enzymes are ____________________. (can select more than one answer) -biological catalysts. -present in living cells. -increases the energy of activation. -all of the above
present in living cells. biological catalysts
What causes the water in the autoclave to get above 100 degrees C?
pressure
the main goal of aseptic techniques is to_
prevent contamination
Aseptic technique is used to _
prevent contamination of sterile substances or objects
How does tetracycline, erythromycin, chloramphenicol and streptomycin work?
prevent protein synthesis by inhibiting polypeptide formation, effect the ribosome of the bacteria
Lyophilization
prevents the formation of damaging ice crystals
Translation
process in which a sequence of Nucleotides in mRNA is used by Ribosomes to make Polypeptides with specific Amino Acid Sequences
Transcription
process involved in the transfer of genetic information where information in DNA is copied as RNA Nucleotide sequences
Translation
process involved in the transfer of genetic information where polypeptides are synthesized from mRNA Nucleotide sequences
methylation
process that plays a role in the control of genetic expression, initiation of DNA Replication, Protection against Viral infection, and Repair of DNA
All of the following are associated with the process of glycolysis EXCEPT __________. -substrate-level phosphorylation -phosphorylation of glucose -production of NADPH. -production of pyruvic acid
production of NADPH
Vibrio cholerae
prokaryote that has 2 chromosomes
Agrobacterium tumefaciens
prokaryote that transfers genes into plants (forming galls) and also has 2 chromosomes (1 circular and 1 linear)
70S
prokaryotic ribosomes
An operon consists of _________, ___________, and __________ and is associated with a regulatory gene.
promotoer, operator, a series of genes
an inhibitor of a viral protease
protease inhibitor
inhibit the processing of large viral proteins into individual components, disrupt capsid formation
protease inhibitors
bacteriocin
protein that destroys other bacteria, usually closely related species - coded for by plasmids
Denaturation is most often a problem with which of the following? -nucleic acids -proteins -carbohydrates -lipids
proteins
Folic acid is used to make purines and __________, part of the building blocks of nucleotides, which are used for the synthesis of the nucleic acids DNA and RNA.
pyrimidines
During fermentation, which compound is the substrate to be reduced with the electrons from NADH? glucose pyruvic acid oxygen ATP
pyruvic acid
Which of the following is NOT an organic acid produced by the process of fermentation? butyric acid lactic acid pyruvic acid succinic acid formic acid
pyruvic acid
a synthetic antibacterial compound that interacts with DNA gyrase and prevents supercoiling of bacterial DNA
quinolone
What is the function of rRNA?
rRNA combines with ribosomal polypeptides to form ribosomes
Shorter Wavelength Radiation
radiation that has more energy and greater penetration
How are tissue grafts sterilized?
radiation; heat would destroy the tissue
Mutations
rarely lead to a protein having a novel property that improves the ability of the organism and its descendents to survive and reproduce
genetic engineering can also be called as_
recombinant DNA technology
transgenic organisms
recombinant plants and animals that have been altered for specific purposes by the addition of genes from other organisms.
Heat treatment in pasteurization is brief to_
reduce alteration of taste and nutrients
A __________ medium is used to grow obligate anaerobes, while an __________medium is most often used for growing fastidious bacteria that have very specific nutritional requirements.
reducing;enrichment
inverted repeat
region of DNA that is a palindromic sequence (reads same forward and backward) such as GAATTC and CTTAAG
Which of the following correctly describes antisepsis? A. destruction of vegetative microorganisms on inanimate surfaces B. removal of vegetative microorganisms from living tissue C. reduction of microbial cells on eating or drinking utensils D. destruction of all organisms on any surface
removal of vegetative microorganisms from living tissue
Degerming
removing microbes from a surface by scrubbing (washing hands; preparing area of skin for an injection)
DNA repair
repair of pyrimidine dimers - light repair, dark repair base excision repair - mismatch repair - SOS response - extreme and cells cannot cope with damage
According to the eight statements that guide the metabolic processes, Cells typically _____________once they have doubled in size.
reproduce
Refrigeration will not kill most bacterial cells. Instead, it simply slows their metabolism and prevents them from __________.
reproducing.
What is the ultimate outcome of metabolic activity?
reproduction
All bacteria __________. -possess the same metabolic enzymes -require energy in order to survive -carry out aerobic respiration -All of the above are correct.
require energy in order to survive
Sulfer
required for 2 amino acids
Phosphorus
required for ATP, phosphlipids (gram-), nucleotides, nucleic acids
Nitrogen
required for anabolism of amino acids for protiens, nucleotides
A vaccines primes the immune system to_
respond quickly and effectively when confronted with pathogens and their toxins
Amphibolic reactions are those that can proceed in either direction, thus are (reversible/irreversible)
reversible
E site
ribosomal binding site that discharged tRNA exits from
Metabolic processes are guided by eight elementary statements. Statement 7: Cells grow by assembling macromolecules into cellular structures such as ______________, membranes, and cell walls.
ribosomes
steps to making new proteins translation overview
ribosomes (polypeptide factories) use the information of the nucleotide sequence to make new polypeptides of specific amino acid sequences try this analogy using an automobile factory: Train boxcars deliver auto parts to the factory at the correct times and in the correct order to manufacture one of the large variety of automobile models, depending on the instructions from corporate headquarters delivered by a special courier. Molecules of tRNA (transfer RNA) deliver the pre-formed amino acids (auto parts) to a ribosome (the factory) which can manufacture an infinite variety of polypeptides (car models) by assembling amino acids (auto parts) in the correct order according to instructions from DNA (corporate headquarters) delivered by mRNA (messenger RNA)(the special courier)
Translation
ribosomes use the genetic information of nucleotide sequences to synthesize polypeptides composed of specific amino accid sequences. Small ribosomal subunit attaches to mRNA near the start codon (AUG), the anticodon of tRNA aligns with the start codon on the mRNA, then the larger ribosomal subunit attaches to the mRNA. Then the elongation of the polypeptide begins, the tRNA produces a polypeptide chain of amino acids that grows out of the top of it, then once its formed the empty tRNA is popped off the E site. The P site is what holds the growing polypeptide chain. The A site recieves the new tRNA (in eukaryotes & prokaryotes it occurs in the cytoplasm)
-RNA molecules functioning as enzymes
ribozymes
histones
round protein molecules around which DNA is tightly coiled in chromatin
Scientists now use recombinant DNA technology to produce _
safer vaccines
inocolum
sample of microorganisms
an agent that reduces microorganisms to a safe level, but may not eliminate them
sanitizer
Anaerobic media
see differences in oxygen requirements
Transposons
segments of DNA that move from one location to another in the same or different DNA molecule
the ability of a compound to inhibit or kill pathogenic microorganisms without adversely affecting the host
selective toxicity
What are the basic modes of action of antibiotics?
selective toxicity, targets what is different between bacteria and other cells (PG cell walls, DNA gyrase, folic acid pathways, etc.)
A daughter DNA molecule is composed of one original strand and one new strand because DNA replication is ______________.
semi conservative
Palindromic Sequences
sequences of DNA nucleotides identical to the inverted sequence in the complementary strand
Triphosphate Deoxyribonucleotides
serve both as monomers and energy in DNA replication
Genotype
set of genes in the Genome
Which of the following steps does NOT result in the production of available free energy? the third step the eighth step the fifth step the seventh step the fourth step
seventh step
Three effects of point mutations are __________, ____________ and ___________.
silence, missence, nonsense
Three effects of point mutations are _______-,_________ and ____________.
silence, missense, and nonsense
Effects of mutations
silent mutations - no real change missense mutation - translation makes sense, but not the right sense nonsense mutation - usually results in nonfunctioning protein
2. A toxic form of oxygen, _____ oxygen, is molecular oxygen with electrons that have been boosted to a higher energy state.
singlet
A toxic form of oxygen, _____________ oxygen, is molecular oxygen with electrons that have been boosted to a higher energy.
singlet
A medium can also become a selectively medium when a_
singular crucial nutrient is left out of it
Promoter
site at which RNA Polymerase binds to start Transcription
Operator
site at which a Repressor (protein) binds to prevent Transcription; lies between the Promoter and Structural Genes
A toxic form of oxygen,_________ oxygen, is molecular oxygen with electrons that have been boosted to a higher energy state.
slinglet
Listeria monocytogenes
small gram-positive, non-spore-forming rod is a facultative intracellular parasite that grows in the cold and is associated with unpasteurized milk products, deli products
___________ RNA and __________ RNA are antisense; that is, they are complementary to another nucleic acid molecule.
small interfering, micro
Plasmids
small molecules of DNA that replicate independently of the Chromosome, carry information required for their own replication and often for one or more cellular traits, are not essential for normal bacterial metabolism, growth, or reproduction, and can confer survival advantages to cells
Agar
solidifying agent (what you add to the media to make it solid) Two types of solid media: plate and slant
Fungi and Protozoa
some ________ ___ ____________ carry Plasmids
Mutations
some make no difference
Pseudomonas
some species of this microorganism have Plasmid genes coding for enzymes allowing them to use Toluene, Camphor, and Petroleum Hydrocarbons for their primary sources of Carbon and Energy
Genes
specific sequence of nucleotides that codes for polypeptide or an RNA molecule.
Genes
specific sequences of Nucleotides that codefor Polypeptides or RNA molecules
Anaerobic media
stab cultures
Scientists, laboratory technicians, and health care workers routinely follow_
standarized aseptic technique
Because the number of dying cells is roughly equal to the number of cells still dividing, the graph appears as a flat line during ____________phase
stationary
a chemical agent that destroys all forms of microbial life
sterilant (sterilizer) (sporicide)
the killing or removal of all living organisms and their viruses from a growth medium, i.e. autoclaving
sterilization
In Pasteruization microbes _
still remain and eventually cause spoilage
UGA
stop codon that may code for a 21st amino acid; Selenocysteine
10. A student observes a researcher streaking a plate numerous times, flaming the loop between streaks. The researcher is likely using the _____ method to isolate microorganisms.
streak plate
A student observes a researcher streaking a plate numerous times, flaming the loop between streaks. The researcher is likely using the _______ method to isolate microorganisms.
streak plate
What is the most common used isolation technique in microbiological laboratories?
streak plate
Active site on an enzyme is shaped complimentary to the shape of the __________.
substrate
What is the method by which glycolysis produces ATP?
substrate-level phosphorylation
The process of moving a phosphate from metabolic products to ADP to form ATP is called __________. -substrate-level phosphorylation. -oxidative phosphorylation. -glycolysis. -reduction.
substrate-level phosphorylation.
Organic materials present
such as fat, feces, vomit, blood, and the intercellular secretions in biofilms interfere with the penetration of heat, chemicals, and some forms of radition and in some instances inactivate chemical disinfectants
UV light
suitable for disinfecting air, transparent fluids, and surfaces of objects
-This is a toxic form of oxygen.
superoxide radicals
Type of Microbe present
susceptibility of microbes to certain antimicrobial agents will help determine route and method. Endospores- bacillus & clostridium are most resisten forms of life
What is the function of tRNA?
tRNA delivers the correct sequence of amino acids to ribosomes based on nucleotide sequence in mRNA
What is the structure of tRNA?
tRNA has a clover leaf structure with 3 main hairpin loops
How many ribonucleotides are in a sequence of tRNA?
tRNA has a sequence of 75 ribonucleotides
How does tRNA work?
tRNA transfers the correct AA to a ribosome during polypeptide synthesis
Goal of recombination DNA technology
take two pieces of DNA that weren't together before and to link them together
Direct microscopic count
takes a long time to count, also counts dead cells bc its difficult to differentiate between the two
All of the following can possibly denature proteins EXCEPT __________. -alkaline pH -temperatures exceeding the maximum growth temperature -temperatures below the minimum growth temperature -acid pH
temperatures below the minimum growth temperature. (Organisms may survive below this temperature and proteins are not denatured; they simply won't reproduce)
Chemical methods of microbial control
tend to be more effective against enveloped viruses and vegetative cells of bacteria, fungi, and protozoa
What antibiotic is used to kill Rickettsia and Chlamydia?
tetracycline
contain four rings, widespread medical use in humans and animals, broad spectrum inhibition of protein synth, also inhibits function of bacterial ribosome
tetracyclines
Differentiate media take advantage of the fact_
that different bacteria utilize the ingredient of any given medium in different ways
What does the CCG codon do?
the CCG codon codes for arginine. It has an alternative use as coding for tryptophan in plant mitochondria.
what is the difference between disinfecting and sanitizing?
the arena (private vs public), which public is sanitizing, in which activity takes place
phosphate
the back bone of the DNA structure and has a negative charge
Another name for the Krebs cycle is ____________. -the acetyl CoA cycle. -the citric acid cycle. -the transition cycle. -the bridge cycle.
the citric acid cycle
Enzyme activity proceeds at a rate proportional to .........until all the active sites are filled.
the concentration of substrate molecules
Sterilization
the destruction of all microbes, including Bacteria, Viruses, and Endospores in or on an object - but NOT Prions
Horizontal Gene Transfer
the donor cell contributes part of its Genome to a recipient cell of the SAME GENERATION
F (Fertility) Plasmid
the donor cell in conjugation has this, which contains the gene for the conjugation Pilus
genome
the entire genetic complement of an organism; includes Genes and Nucleotide Sequences
RNA primase
the enzyme that adds primers to mark the areas where DNA replication is occurring
helps protect the cell
the fact that there may be more than one codon for an Amino acid, but the multiple codons only code for the one amino acid does what for the cell if there are errors in DNA or RNA Transcription
what happens when RNA Polymerase reaches the Adenine-rich part of the Terminator Sequence
the fewer H Bonds of Adenine Bases are unable to withstand the pressure, so the RNA transcript separates from DNA
Which step of the Krebs cycle involves GTP? -the third step -the fourth step -the seventh step -the first step -the fifth step
the fifth step
mRNA is the deliver device of_
the gene of interest
To eliminate phenotype traits you should change_
the genotype of the organism
maximum growth temperature
the highest temperature at which an organism continues to metabolize
complementary structure
the key to DNA replication is the ___________ __________ of the 2 nucleotide strands of DNA
RuBP is an important part of which of the following pathways? -chemiosmosis in cellular respiration -the light-dependent reactions of photosynthesis -the light-independent reactions of photosynthesis -the Krebs cycle in cellular respiration
the light-independent reactions of photosynthesis
RuBP is an important part of what pathway?
the light-independent reactions of photosynthesis. *Side Note-RuBP, which stands for ribulose 1,5-bisphosphate, is necessary for carbon fixation during the Calvin-Benson cycle that occurs as part of the light-independent reactions of photosynthesis.
Biological oxidations often involve which of the following? the loss of a hydrogen atom the gain of an electron the loss of an oxygen atom the gain of an oxygen atom
the loss of a hydrogen atom
minimum growth temperature
the lowest temperature at which an organism is able to conduct metabolism
Thermal Death Point
the lowest temperature that kills all cells in a broth in 10 minutes
steps to making new proteins genetic codes (codons and anticodons)
the mRNA (messenger RNA) that is bringing the information to the ribosome from DNA carries the information in "triplets" such as AAA or AAU for example. The triplets are called "codons". The ribosome has docking stations where the codons park and wait for the tRNA (transfer RNA) to bring the amino acids in triplet form that are the partners of the codons. These partners are the "anti-codons" and will follow the same rules such as U to A and G to C There are 3 codons that are a code for the ribosome to stop translating... UAA, UAG, UGA
leading strand
the new continuous complementary DNA strand synthesized along the template strand in the mandatory 5' --> 3' direction
obligate or strict
the only condition that it needs to grow!
When Lactose is present
the organism converts some of it to Allolactose which binds to a Repressor and prevents it from binding to the Operator- this allows RNA Polymerase to attach to the Promoter and transcribe Structural Genes
What happens to the microorganism if the temperature exceeds the maximum growth temperature?
the organism's proteins are permanently denatured, and it dies
Sanitization
the process of disinfecting public areas or utensils used in public place to reduce the number of pathogens to meet accepted Public Health Standards
transduction
the process of transfering genetic material from one cell to another by a plasmid or bacteriophage
What happens after cycle 1 in PCR?
the process starts again with denaturation
replication
the process whereby DNA makes a copy of itself before cell division
translation
the process whereby genetic information coded in messenger RNA directs the formation of a specific protein at a ribosome in the cytoplasm
transcription
the process whereby the DNA sequence in a gene is copied into mRNA
What is the end result of the Calvin-Benson cycle? the production of carbon dioxide the production of sugars and water the generation of NADPH the production of ATP
the production of sugars and water
Genetic recombination
the regrouping of genes in an offspring that results in a genetic makeup that is different from that of the parents
Deamination is __________. -the process that bacteria use to break down proteins into amino acids -the process used to synthesize amino acids -the removal of an amine group from an amino acid -a type of anabolism
the removal of an amine group from an amino acid
Frameshift Insertion
the result of Transposons moving from one location to another in the same or different DNA molecules (Transposition)
transposition
the result of the action of a "transposon". it is a kind of "frameshift insertion"
What does the term "cyclic" refer to in cyclic photophosphorylation? -the cycle of oxidizing water to make molecular oxygen -the cyclic motion of ATP synthase -the return of excited electrons back to photosystem I -the cycle of ATP production and ATP utilization
the return of excited electrons back to photosystem I
Which step involves the reduction of FAD+ to FADH? the third step the third step the second step the fifth step the sixth step
the sixth step
Temperature plays an important role in microbial life through its effects on_
the three-dimensional configurations of biological molecules
Thermal Death Time
the time to sterilize a volume of liquid at a set temperature
Transduction
the transfer of Genes from one cell to another via a replicating Virus- a Bacteriophage (or Phage) in bacteria; can also occur in Eukaryotes
Conjugation
the transfer of genes from a live donor cell to a recipient cell by means of a Sex Pilus which attaches the donor cell to the recipient
Antiparallel
the two nucleotide chains in DNA are _____________, oriented in opposite directions; one running in 3' to 5' direction, the other in 5' to 3' direction
what is the risk behind vaccines?
the use of vaccines entails a risk->they may cause the disease they are designed to prevent
central dogma
theory that states that, in cells, information only flows from DNA to RNA to proteins
Bacterial cultures go through lag phase because .....................
they are synthesizing new enzymes in order to use nutrients in their medium
Log Phase
they enter a phase of rapid chromosome replication, growth, and reproduction. The population increases logarithmicallly and the reprodcutive rate reaches a constant as DNA and protein synthesis are maximized. Most suseptable to antimicrobial drugs.
where bacteria and archae are classified within these categories?
they exhibit greater metabolic diversity than any other group, with members in all four groups
Facultative
they have the option (operate aerobic or anaerobic)
why anaerobes are susceptible to action of hydrogen perioxide?
they lack catalase and/or perioxidase
DNA Polymerase I
this enzyme replaces RNA Primers with DNA and also PROOFREADS the Daughter Strand in the Synthesis of the Lagging Strand
G-C Base portion
this portion of the Terminator sequence slows down the unwinding of DNA due to the presence of 3 H bonds between their pairs, forming a loop which puts pressure on RNA Polymerase and DNA
Self-Termination
this type of termination occurs when RNA Polymerase reaches the Terminator Sequence in DNA- which is one composed mostly of Guanine-Cytosine Bases followed by one mostly of Adenine Bases
Most common nutrients
those containing necessary elements such as carbon, oxygen, nitrogen, and hydrogen
Mesophiles
those growing best between 20 degrees and 40 degrees celcius; the human pathogens are in this group
Inducible Operons
those that are not transcribing unless activated by Inducers
Repressible Operons
those that are transcribing continually unless deactivated by Repressors
Nucleotide Sequences
those that do not code for polypeptides or RNA molecules, but connect Genes to one another
Based on the animation, how many ATP is one NADH equal to? one two three four five
three
Including the transition step, how many carbon dioxide molecules are produced in the Krebs cycle from the 3-carbon compound pyruvic acid? one two three four
three
The light reactions take place in the _________ and the Calvin cycle takes place in the _________. -thylakoids; stroma -mitochondria; chloroplasts -chloroplasts; mitochondria -stroma; thylakoids -inner membrane; outer membrane
thylakoids; stroma -Within the chloroplast, the light reactions take place in the flattened sacs called thylakoids and the Calvin cycle takes place in the thick fluid called the stroma.
Heterochromatin
tightly-packed chromatin fibers where genes are inactive
What are the two most important aspects of sterilization?
time and temperature
How the scientists use the DNA pieces produced by restriction enzyme?
to combine pieces of DNA from different organism into a single recombinant DNA molecule
The overall purpose of the Krebs cycle is ________. -to convert puryvic acid into acetyl CoA. -to produce molecules of the energy carrier GTP. -to produce carbon dioxide and water. -to extract the energy from pyruvate molecules enzymatically
to extract the energy from pyruvate molecules enzymatically
The function of the chlorophyll is _______________. -to produce ATP by fusing ADP and an inorganic phosphate. -to harvest the energy from light to power photosynthesis. -to capture carbon dioxide from the atmosphere. -to provide a barrier that enables a proton gradient to form.
to harvest the energy from light to power photosynthesis
For what is the ATP produced during photosynthesis primarily used? -to capture energy from sunlight -to split water -to pass electrons -to help make glucose in the Calvin-Benson cycle
to help make glucose in the Calvin-Benson cycle
what is one goal of recombinant DNA technology that is related to vectors?
to insert a useful gene into a cell so that the cell has a new pheontype
The role of the cytochrome proteins is ___________________________________-To harvest light energy from the sun to energize electrons. -to pass electrons along the thylakoid membrane, creating a proton gradient. -to fuse ADP to an inorganic phosphate to yield ATP. -to split water into hydrogen ions and molecular oxygen.
to pass electrons along the thylakoid membrane, creating a proton gradient.
The redox reactions in an electron transport chain pass electrons from one membrane-bound carrier to another, and then to the final electron acceptor. The energy from these electrons is used for what?
to pump protons across the membrane
Large Ribosomal Subunit
towards the end of the Initiation stage of Translation, what attaches to complete the Initiation Complex?
What is the process of transfering an amine group from one amino acid to another.
transamination
reverse transcriptase
transcriptase is an enzyme that transcribes DNA nucleotides from an RNA template.
____________ RNA carries amino acids.
transfer
tRNA
transfer RNA brings amino acids to ribosome mRNA complex
tRNA
transfer RNA; type of RNA that carries amino acids to the ribosome
Transformation
transfer of Genes by the uptake of DNA from the environment by a recipient cell; the source of DNA is a donor cell which has died and released its DNA there
Conjugation
transfer of plasmids froma donor to a recipient cell
Generalized transduction
transfers a wide variety of bacterial genes
Glycolysis __________. -transfers electrons from a substrate to NAD+ -yields less ATP than it uses -uses water to break glucose into two 3-carbon molecules -occurs in the cytoplasm of bacteria and mitochondria of eukaryotic cells
transfers electrons from a substrate to NAD+
Specialized Transduction
transfers only bacterial genese adjacent to the viral DNA
which process moves plasmids (vector) inside bacteria?
transformation
A gene for antibiotic resistance can move horizontally among bacterial cells by ______, ________, and _________.
transformation, trandsduction, and bacterial conjugation.
A gene for antibiotic resistance can move horizontally among bacterial calls by ____________, ____________ and ____________.
transformation, transduction, bacterial conjugation
Recombinant DNA technology has been applied to the realm of agriculture to produce_
transgenic organisms
______________ are nucleotide sequences containing palindromes and genes for proteins that cut DNA strands.
transposons
Complex Transposons
transposons that contain one or more genes not connected with transposition (e.g. antibiotic resistance)
Complex transposons
transposons that contain one or more genes not connected with transposition (e.g. antibiotic resistance)
complex transposons
transposons that contain one or more genes not connected with transposition (e.g. antibiotic resistance)
Activation energy-amount of energy needed to ......
trigger a chemical reaction
- lipids which are a major organic source of carbon for cells.
triglycerides
Codons
triplets of mRNA Nucleotides, most of which code for an Amino Acid
A chemostat could be used to keep a bacterial culture in the log phase indefinitely. True False
true
A holoenzyme is a combination of an apoenzyme bound to its particular cofactor. True False
true
Bacteria that are pathogenic for humans are usually classified as mesophiles. True False
true
Bacteria use the process of amination when synthesizing amino acids. True False
true
Bacterial proteases typically do their work outside the cytoplasmic membrane. True False
true
Blood agar is an example of a complex medium. True False
true
During cellular respiration, carbon dioxide is produced only as a by-product of acetyl-CoA synthesis and the Krebs cycle. True False
true
Enzymatic reactions reach a saturation point when the active sites of all enzymes present are occupied by substrate molecules. True False
true
Facultative halophiles do not require the presence of high salt concentrations in order to grow. True False
true
Flow cytometry involves the counting of cells that have fluorescent dyes associated with them. True False
true
Oxidation does not always involve oxygen. true flase
true
Some bacteria use electrons carried by NADH to generate light instead of ATP. True False
true
The Calvin-Benson cycle would be considered to be primarily anabolic. True False
true
The majority of bacteria and archaea have not or cannot be grown in the laboratory. True False
true
When organisms are exposed to temperatures higher than their maximum growth temperature, their proteins are permanently denatured. True False
true
bacteria do not have a mitochondrion. true false
true
Which of these media is NOT an example of a differential medium? -trypticase soy agar -carbohydrate utilization broth -blood agar -MacConkey agar
trypticase soy agar
tryptophan operon
tryptophan (trp) operon consists of promoter, operator, five genes involved with tryptophan synthesis E. coli can synthesize all the amino acids it needs for protein synthesis , but if it can save energy by using amino acids in the environment. So, E. Coli represses the gene. this is an example of a "repressible" gene
deeps
tubes that contain solidified agar and they were kept vertical when the agar was solidifying
All of the following are direct methods of measuring microbial growth EXCEPT __________. -a Coulter counter -viable plate counts -turbidity - membrane filtration
turbidity
Which of these is NOT a direct method of measuring microbial reproduction? -serial dilution and viable plate counts -microscopic counts -turbidity -Coulter counter
turbidity
what is the faster technique to measure quantity of microbes in a solution?
turbidity by using spectrophotometer
What is the net ATP produced from one molecule of glucose in glycolysis? -one molecule -two molecules -four molecules -six molecules
two molecules
Which of the following are products remaining after glycolysis has occurred for a single molecule of glucose? (possibly more than one answer) -two NAD+ -two NADH -four total ATP -four net ATP -two molecules of pyruvic acid
two molecules of pyruvic acid four total ATP two NADH
Bacteriocin Factors
type of Plasmid that contain genes for protein toxins which kill bacteria of the same or similar species that lack the factor
Resistance Factors
type of Plasmid that contain genes for resistance to one or more Antimicrobial drugs or toxic Heavy Metals
Fertility Factors
type of Plasmid that contain instructions for Conjugation (transfer of genes from one bacterial cell to another)
Virulence Plasmids
type of Plasmids that contain genes for structures, enzymes, or toxins which enable bacterium to be pathogenic
Virulence Plasmids
type of Plasmids that contain genes for structures, enzymes, or toxins which enable bacterium to be pathogenic E. Coli
70S Ribosomes
type of Ribosomes that occur in Prokaryotic cells and in Mitochondria and Chloroplasts of Eukaryotic cells
Specialized Transduction
type of Transduction where only certain donor DNA sequences are transferred
Generalized Transduction
type of Transduction where the transducing Phage carries random DNA segment from the donor to the recipient
Eukaryotes
typically have more than one chromosome per cell and chromosomes are linear and sequestered within a membrane-bound nucleus
Small, lipid-soluble, nonprotein electron carriers are ___________. flavoproteins. cytochromes. ATP synthase. ubiquinones.
ubiquinones
Incineration
ultimate means of sterilization
Aerobes
undergo aerobic respiration
All of the following are true statements regarding clinical specimens EXCEPT __________. Clinical specimens must be properly labeled. -clinical specimens include saliva, feces, and blood -universal precautions are observed in order to protect specimens from contamination -clinical specimens are often transported in special media to help preserve them
universal precautions are observed in order to protect specimens from contamination
What is phage therapy? What is a problem with this?
use a bacteriophage to lyse a pathogen. Possible because phages are very specific Problem: G- bacteria release endotoxin from their LPS when lysed, which would cause abrupt drop in blood pressure and possibly death
Antisepsis
use of Chemical Agents to destroy microorganisms on SKIN or MUCOUS MEMBRANES of the body
Disinfection
use of Physical or Chemical Agents to destroy microorganisms, especially pathogens, on NONLIVING objects
Pasteurization
use of heat to kill pathogens and most spoilage organisms in food and beverages without altering the quality of the food
HEPA filters are used to sterilize what?
used in A/C systems
Formalin
used in embalming and disinfection of rooms and instruments
Gaseous Agents
used in hospitals and dental offices
Intermediate-level germicides
used to disinfect noninvasive instruments in contact with mucous membranes (endoscopes and respiratory equipment)
Low-level germicides
used to disinfect objects only in contact with skin (electrodes and furniture)
High-level germicides
used to sterilize invasive instruments (catheters, implants, and parts of heart-lung machines)
Gamma Rays
used to sterilize meats, spices, and fresh fruits and vegetables
Electron beams
used to sterilize spices, meats, microbiological plastic ware, and medical and dental supplies
DNA Polymerase III
uses Energy from Triphosphate Deoxyribonucleotides to form H Bonds with Complementary Bases in Parental Strand and join nucleotides together in Daughter Strand; also PROOFREADS by cutting out and replacing any mismatched Nucleotides with the proper ones
Oxidative phosphorylation __________. -uses energy from a proton motive force to add phosphate to ADP -occurs in glycolysis -uses light energy to make ATP -involves transfer of phosphate from a phosphorylated substrate to ADP
uses energy from a proton motive force to add phosphate to ADP
an agent that stops viral replication and activity
viricidal agent
an agent that inhibits viral replication
viristatic agent
Colony
visible population of microorganisms living in one place; an aggregation of cells arising from a single parent cell
Examples of sanitization
washing tableware in scalding water in restaurants
Microorganisms require_
water
What is the source of electrons in noncyclic photophosphorylation? photosystem I oxygen water NADPH ATP
water
Which of the following contributes to osmotic pressure in a cell?
water
Ionizing radiation
wavelengths shorter than 1 nm, and includes Electron beams, Gamma Rays, and X Rays
Uracil
what Nitrogen Base is incorporated in place of Thymine by the RNA Polymerase?
2 sets of enzymes, 2 replication forks, 2 leading strands, and 2 lagging strands
what are involved in Bacterial DNA replication due to the fact that it's bidirectional?
Elongation Factor and energy
what are required from GTP in the Elongation stage of Translation?
energy
what do initiation and elongation of Translation require from GTP (Guanosine Triphosphate)
conserve energy
what does the regulation of genetic expression allow the cell to do?
DNA Ligase
what enzyme joins Okazaki Fragments together?
chromosomal proteins are removed
what happens first in DNA replication?
they are regulated
what happens to the other 25% of genes that aren't expressed at all times, but are only transcribed and translated when the cell needs them?
Mitochondria
what is the fourth type of RNA Polymerase used in?
Pasteurization
what is the moist heat method used today for milk, ice cream, yogurt, and fruit juices that is NOT sterilization, because is allows Heat-tolerant (Thermoduric) and Heat-loving (Thermophilic) microbes to survive?
Cell wall
what maintains the integrity of the cell and ,when disrupted, cannot prevent the cell from bursting due to Osmotic Effects?
mRNA must be processed
what must happen in Eukaryotic Transcription before Translation?
75%
what percentage of genes are expressed at all times?
All of the following statements concerning the bacterial growth curve are true EXCEPT __________. -when death phase is reached, all cells in the culture have died -during stationary phase, the number of dying cells equals the number of cells being produced - under certain conditions, the log phase can be maintained indefinitely -cells divide at a maximal rate during the log phase
when death phase is reached, all cells in the culture have died
Cytosol
where does the Ribosome release tRNA to from its E site?
termination
where transcription ends
RNA Polymerase
which Polymerase works slower, RNA Polymerase or DNA Polymerase?
Prokaryotic mRNA
which mRNA can begin to be translated by Ribosomes before transcription is complete since they both occur in the cytoplasm?
Eukaryotic mRNA
which mRNA carries instructions for only ONE Polypeptide?
Eukaryotic mRNA
which mRNA is not translated until fully transcribed, processed, and exits the nucleus?
Eukaryotic mRNA
which mRNA requires extensive processing before Translation?
Prokaryotic mRNA
which mRNA usually codes for several polypeptides?
In which two organisms the insulin was first introduced? (they are commonly used in our days)
yeast and bacteria
What is a bacterial colony and how can it be used to identify and classify a microbe?
• A bacterial colony is colonies of bacteria isolated within a petri dish that has distinctive characteristics that help in identifying the microbial species that formed the colony. • It can be used to identify and classify a microbe by using the specific characteristics including color, size, shape, elevation, texture, and appearance of the colony's margin (edge). All taken together aid in identifying the microbial species that formed the colony
What does it mean that bacterial grow logarithimically?
• Bacteria grows exponentially by binary fission • It is calculated as 2^n (n=number of generations) • Logarithmic growth: increase in size of a microbial population in which the number of cells doubles in a fixed interval of time.
Agar
• Solid surface media • Gel-like polysaccharides isolated from red algae and used as thickening agent • Media made solid by addition of agar to broth
slant tubes or slants
•Test tube containing agar media that solidifies while the tube was resting at an angle
DNA replication
DNA stands seperate at origin by helicase unzipping the double helix; each strand is a template for a new strand. Enzyme for DNA polymerase (proofreading recognizes errors) brings in complementary nucleotides. Continuous and discontinuous synthesis of a new strand. Leading strand is always synthesized toward the replication fork. Lagging strand proceeds away from the replication fork.
Linker DNA
DNA that runs between adjacent nucleosomes
DNA template
DNA to be copied
What type of pentose sugar is found in DNA? RNA?
DNA use deoxyribose RNA uses ribose
Viral Replication
Damage to the Viral Envelope interrupts what?
During which phase of bacterial growth will the number of dying cells exceed the number of new cells being made?
Death phase
Pressure
Deep of the ocean (pressure) some organisms need this pressure to keep their shape
Long term storage of cultures at temps ranging from -50 degrees Celsius to -95 degrees celsius.
Deep-freezing
Culturing medium of which the exact chemical composition is known.
Defined medium (synthetic medium)
If the molecule that donates the electron is part of a hydrogen atom, the oxidation reaction is also called ________________.
Dehydrogenation
Effects of high temperatures
Denaturation of proteins, interference with the integrity of cytoplasmic membranes and cell walls, and disruption of the structure and function of nucleic acids
Gaseous Agents
Denature Proteins and DNA by cross-linking Functional Groups
How are deoxyribonucleotides attached to each other?
Deoxyribonucleotides are attached to each other through their sugar and phosphates (phosphodiester bonds)
Sterilization
Destruction of all microorganisms and viruses in or on an object
Disinfection
Destruction of most microorganisms and viruses on nonliving tissue
Disinfection
Destruction of most microorganisms and viruses on nonliving tissue (using disinfectants)
What is the treatment for diabetes Type II?
Diet & Exercise.
Which of these statements does NOT describe differential media? -Blood agar is considered a differential medium. -Differential media favor the growth of some organisms while inhibiting the growth of others. -It is possible for some differential media to also be selective. -Carbohydrate fermentation tubes can be considered differential media.
Differential media favor the growth of some organisms while inhibiting the growth of others.
Serial dilution
Dilution of a substance several times by the same amount each time.
Eukaryote Genomes
Diploid linear chromosomes inside of a nucleus, histones used for packaging DNA, plasmids are rare; extracellular DNA in mitochondria, chloroplasts is bacterial DNA
Which of the following is NOT a step in bacterial cell division? -splitting apart of two new daughter cells -disappearance of nuclear envelope -replication of the genetic material cell elongation
Disappearance of nuclear envelope
Petri plates
Dish filled with solid medium used in culturing microorganisms
During Rho-dependent termination, where does Rho bind to?
During Rho-dependent termination, Rho binds to a specific RNA sequence near the end of an RNA transcript.
elongation
During protein synthesis, the growth of the polypeptide chain through the addition of amino acids; the second step in translation.
Peptide Bond
During the Elongation stage of Translation, Ribozymes in the Large Ribosomal Subunit form a _________ _____ between the Amino Acid attached to tRNA at the P site and the newly introduced Amino Acid- shifting the chain to tRNA at the A Site
tRNA with the Anticodon (UAC)
During the Initiation stage of Translation, after the small ribosomal subunit attaches to mRNA at the Ribosome binding site, what attaches to the P site?
Release Factors
During the Termination stage of Translation, _________ _________ somehow recognize Stop Codons and modify the Ribosome to activate Ribozymes in the Large Ribosomal Subunit, which severs the Polypeptide from the final tRNA
Small Ribosomal Subunit
During the initiation stage of Translation, what attaches to mRNA at a Ribosome Binding site with the Start Codon at its P site?
During the synthesis of the LEADING strand, what is the function of triphosphate deoxyribonucleotides?
During the synthesis of the LEADING strand, deoxyribonucleotides form hydrogen bonds with their complements in the parental strand.
Which of the following is NOT a semisynthetic penicillin? A. methicillin B. oxacillin C. ampicillin D. carbenicillin E. penicillin G
E
What is an example of facultative anaerobes?
E. Coli
what is the benefit of using reverse transcriptase?
Easier to isolate mRNA molecule for desired protein first (than finding the gene of interest in the cell genome to get mRNA and then get protein)
Temperature has effect on_
Effect of temperature on proteins (tertiary structure) Effect of temperature on lipid-containing membranes of cells and organelles
How does isoniazid work?
Effective only against Mycobacterium Disrupts synthesis of mycolic acid
Selectively media
Either favors growth of particular microbe or inhibits growth of unwanted ones.
________ ________ is a means by which a proton gradient is created, not used.
Electron Transport
________ _________ is a means by which a proton gradient is created, not used.
Electron transport
until RNA Polymerase and Transcribed RNA are released from DNA
Elongation of RNA molecule continues until what happens?
Metabolism is the sum of biochemical reactions within the cells of an organisms, inc. Catabolism, which breaks down molecules and releases ______________, and anabolism , which ______________ molecules and uses energy.
Energy;synthesizes
Sample of material taken from such sources as ponds , soil or air and tested for the presence of microorganisms.
Environmental specimen
DNA polymerase
Enzyme involved in DNA replication that joins individual nucleotides to produce a DNA molecule
How does enzyme dependent termination work?
Enzyme-dependent termination: Rho pushes between polymerase and DNA, releasing polymerase, RNA transcript and Rho.
-organic catalysts often named for their substrates.
Enzymes
Which of the following statements regarding enzymes is false? -Enzymes increase the rate of chemical reactions. -Enzymes increase the total amount of product in a chemical reaction. -The transition of reactants to products requires a certain amount of energy. -Make it easier for cells to produce the products of various chemical reactions in the cell.
Enzymes increase the total amount of product in a chemical reaction.
How does genetic recombination of homologous sequences work?
Enzymes nick one stand of DNA at the homologous sequence and another enzyme inserts the nicked strand into the second DNA molecule. Ligase then reconnects the strands into new combinations.
what was gotten by searching to get protein synthesized by Recombinant DNA technology?
Erythropoietin (Epo) rBGH (rBST)
Some organisms such as ____________ __________ can synthesize everything in their cells just from precurser metabolites;other organisms muct acquire some anabolic building blocks from outside their cells as _______________.
Escherichia coli (E. Coli);nutrients
What is euchromatin?
Euchromatin is loosely packed chromatin fibers?
How are eukaryotic Okazaki fragments different from bacterial Okazaki fragments?
Eukaryotic Okazaki fragments are shorter than those found in bacteria. In eukaryotes, they are typically 100 - 400 nucleotides long.
80S
Eukaryotic Ribosomes
How is DNA polymerase different in eukaryotic cells as opposed to prokaryotic cells?
Eukaryotic cells use four different DNA polymerases.
Increase in size of a microbial population in which the number of cells doubles in a fixed interval of times.
Exponential (logarithmic) growth
Denature proteins
Extreme heat, or certain chemicals do what to proteins?
Using thioglycollate growth medium, how you would know an organism is facultative anaerobes?
Facultative anaerobes can grow with or without oxygen, but their ability to use aerobic respiration pathways enhances their growth near the surface, so they would be found predominantly on the top but also dispersed throughout the tube
The carrier molecules in electron transport chains are all integral membrane proteins. TRue or False and why or why not?
False because Ubiquinones are electron transport molecules that are lipid-soluble, nonprotein carriers.
Metabolic processes are guided by eight elementary statements. Statement 4: Using nutrients, cells catabolize enzymatic molecules to form elementary building blocks called precurser metabolites. True/False?
False! Using enzymes (not nutrients), cells catabolize nutrient (not enzymatic) molecules to form elementary building blocks called precurser metabolites.
The electron transport chain in eukaryotes is located on the outer mitochondrial membrane. TRue or False?
False! this is only true for organisms that require oxygen
- __________ __________(___________ ___________) occurs when the final product of a series of reactions is an allosteric inhibitor of some previous step in the series. Thus, accumulation of the end-product "feeds back" into the series a signal that stops the process.
Feedback inhibition (negative feedback)
- the partial oxidation of sugar to release energy using a cellular organic molecule rather than an electron transport chain as the final electron acceptor
Fermentation
types of Plasmids
Fertility Factors, Resistance Factors, Bacteriocin Factors, Virulence Plasmids, and Dissimilation Plasmids
What do fertility (F) plasmids do?
Fertility plasmids carry instructions for conjugation.
How does splicing work in eukaryotic transcription?
Five small RNA molecules associate with about 300 polypeptides to form a splicesome that acts as ribozyme to splice pre-mRNA into mRNA.
Buff
Full media that is solid, within a tube
Which of the following are a reason that microorganisms are naturally resistant to certain antibiotics A. org lacks structure the antibiotic inhibits B. org is impermeable to antibiotic C. org can inactivate antibiotic D. org may modify the target of antibiotic E. org may develop a resistant biochemical pathway F. org may be able to pump our antibiotic (efflux) G. all of the above
G
Guanine and Cytosine for how many hydrogen bonds?
G - C forms three hydrogen bonds.
Are more G+ or G- bacteria resistant to antibiotics?
G-
Ionizing Radiation
Gamma and X-rays; produces Ions that damage DNA, causing breaks in chromosomes
Clostridium tetani
Genes in the virulence plasma of __________ _________ code for its neurotoxin
What is significant about the "prokaryotic" chromosomes in the chloroplast and mitochondria of eukaryotes?
Genes located at "prokaryotic" chromosomes code for about 5 % of the RNA and polypeptides required for the organelle (mitochondria or chloroplast) replication and function.
redundant but not ambiguous
Genetic code is __________ ___ ___ ____________. (there may be more than one Codon for an Amino Acid, but the multiple codons only code for that amino acid)
What is genetic recombination?
Genetic recombination is the the exchange of nucleotide sequences between two DNA molecules and often involves segments called homologous sequences.
What is genetics?
Genetics is the study of inheritance and inheritable traits as expressed in an organism's genetic material.
Describe pour plate
Get some of the first sample then put it in the second and then get some of the 2nd to put In the next Next tube has less bacterial than the first one
Some cells are able to synthesize glucose from amino acids, glycerol, and fatty acids via a process called ____________.
Gluconeogenesis
Which of the following is NOT TRUE of glucose? -Glucose is a product of aerobic respiration. -Glucose is a monosaccharide. -Glucose can be synthesized from amino acids, glycerol, and fatty acids by some bacteria. -Glucose is a product of the hydrolysis of starch.
Glucose is a product of aerobic respiration
Lipids and proteins can be catabolized into smaller molecules which can be used as substrates for ____________ and _______________.
Glycolysis and Krebs cycle
Which statement describes glycolysis? -Glycolysis converts pyruvic acid to acetyl CoA. -Glycolysis splits glucose in half and produces 2 ATPs for each glucose. -Glycolysis joins 2 pyruvic acid molecules into a molecule of glucose. -Glycolysis uses energy captured from electrons flowing to oxygen to produce most of the ATPs in cellular respiration. -Glycolysis results in the production of carbon dioxide.
Glycolysis splits glucose in half and produces 2 ATPs for each glucose. In glycolysis, glucose is split into two molecules of pyruvic acid. The released energy is stored in ATP and the electron carrier NADH.
Clostridium sp.
Gram + rods, lose ability to retain stain. Produce endospores. Some are aerotolerant, others are strict anaerobes. Catalase negative. Occur in soil and in intestinal tract of man and animals. Some species produce powerful exotoxins.
Examples of photoheterotrophs
Green nonsulfur bacteria and purple nonsulfur bacteria, some archaea
Nitrogenous bases
Guanine (G), Cytosine (C), Adenine (A), Thymine (T), and Uracil (U)
Which of the following is a good target for a chemotherapeutic used to treat a bacterial infection? A. bacterial ribosomes B. the peptidoglycan cell wall C. DNA gyrase D. A, B, and C E. none of the above
D.
Which of the following is true about penicillins? A. discovered by Alexander Fleming B. primarily effective against G+ bacteria with some synthetic forms being effective against some G- bacteria C. target cell wall synthesis D. all of the above
D.
Recombinant is a method to link_
DNA
Triphosphate Deoxyribonucleotides
DNA Nucleotides with 3 Phosphate groups that release energy when the terminal Phosphate Groups break off from molecule
DNA Polymerase Epsilon
DNA Polymerase used by Eukaryotes that elongates the Lagging Strand
DNA Polymerase Delta
DNA Polymerase used by Eukaryotes that elongates the Leading Strand
DNA Polymerase Alpha2
DNA Polymerase used by Eukaryotes that initiates replication, as well as synthesis of Primer
DNA Polymerase Gamma
DNA Polymerase used by Eukaryotes that replicates Mitochondrial DNA
Surfactants
"Surface active" chemicals that reduce Surface Tension of solvents to make them more effective at dissolving solutes
Halophiles
"salt-loving" archaea that live in environments that have very high salt concentrations
deletion
(1) A deficiency in a chromosome resulting from the loss of a fragment through breakage. (2) A mutational loss of one or more nucleotide pairs from a gene.
transduction
(genetics) the process of transfering genetic material from one cell to another by a plasmid or bacteriophage
transposon
(jumping genes) short strands of DNA capable of moving from one location to another within a cell's genetic material
transposons
(jumping genes) short strands of DNA capable of moving from one location to another within a cell's genetic material
transposons
(jumping genes) short strands of DNA capable of moving from one location to another within a cell's genetic material.
Colony
(microbiology) a group of organisms grown from a single parent cell
Why is DNA methylated?
- Control of genetic expression - Initiation of DNA replication - Protection against viral infection - Repair of DNA
How is eukaryotic translation different from prokaryotic translation?
- Eukaryotic cells process pre-mRNA to make mRNA - One molecule of eukaryotic mRNA contains instructions for one polypeptide - Transcription and translation do not occur simultaneously in eukaryotic cells (transcription in nucleus and translation in cytoplasm)
How is RNA polymerase different from DNA polymerase.
- RNA polymerase unwinds and opens DNA by itself, no helicase required - RNA polymerase does not need a primer - Transcribes only one of the DNA strands - Slower than DNA polymerase III - Incorporates ribonucleotides instead of deoxyribonucleotides - Uracil nucleotides are incorporated instead of thymine nucleotides - Proofreading function is less efficient
How is eukaryotic transcription different from prokaryotic transcription?
- RNA transcription occurs in the nucleus (instead of cytosol) - Transcription also occurs in mitochondria and chloroplasts - Three types of RNA polymerases (for mRNA, rRNA, tRNA) - Numerous transcription factors (in contrast to sigma factor) and elongation factors - mRNA processed before translation
Aerotolerant anaerobes
- do not use aerobic metabolism but have some enzymes that detoxify oxygen's poisonous forms
culture
- refers to act of cultivating microorganisms or the microorganisms that are cultivated -Grow from inocolum
Why water is important for microorganisms?
--Because water is needed to dissolve enzymes and nutrients -It is an important reactant in many metabolic reactions
Refrigeration
-0-7*C -inhibits metabolism -preservation of food
When was insulin isolated? (year) when insulin treatment has been used to treat Diabetes?
-1921 -1924
lyophilization (freeze drying)
-196*C for a few minutes while drying -inhibits metabolism -long-term storage of bacterial cultures
lag
-1st phase of microbial growth -No growth -bacteria adjusting to conditions -Synthesis enzymes (nutrients in the medium)
Log
-2nd phase of microbial growth -Population growth increases logarithmically -Researchers interested in this phase because: susceptible to antimicrobial drugs, Gram staining for having intact cell walls, metabolic rate is at maximum
Stationary
-3rd phase of microbial growth # dying = # produced -Nutrients are depleted and wastes accumulate, rate of reproduction decreases -size of population becomes stationary
Death
-4th phase of microbial growth -Too much waste products; Low nutrients. -If nutrients are not added and wastes are not removed -cells die at faster rate than they are produced -"decline phase"
In genetic screening, laboratory technicians use _.
DNA microarrays to screen a patient's blood or other tissues for these genetic mutations before the patient shows any sign of the disease.
Mitochondria and Chloroplasts
DNA molecules of ___________ ___ __________ are circular and resemble Chromosomes of Prokaryotes
Gel electrophoresis allows scientists to isolate_
DNA of interest
What is the term for DNA polymerase III's proofreading function.
DNA polymerase III's proofreading function is known as "proofreading exonuclease function"
Semiconservative
DNA replication is _______________; meaning that the new strands of DNA are composed of one Original (parental) strand and one new Complementary (Daughter) strand
Biofilms
-A slimy community of microbes growing on a surface
plasmid
-A small circular molecule of DNA that replicated independently of the chromosome -each carries genes for its own replication and often for one or more nonessential functions such as resistance to antibiotics -Type of vector
Recombinant DNA technology (information it is based on, what manipulates, the areas it benefits)
-Adapt the natural enzymes and processes of DNA replication, replication, transcription, transformation, transduction, and conjugation to manipulate genes for industrial, medical, and agricultural purposes
Classification of based on oxygen requirements
-Aerobes -Anaerobes -Facultative anaerobes -Aerotolerant anaerobes -Microaerophiles
What are the processes that chemohetrotrophs preform? Give examples
-Aerobic respiration: Most animals, fungi, protozoa, and many bacteria -Anaerobic respiration: some animals, protozoa, bacteria, and archaea -Fermentation: some bacteria, yeasts, and archaea
what agarose do in gel electrophoresis technique?
-Agarose makes up gel -acts as molecular sieve that retards the movement of DNA fragments down the chamber and separates the fragments by size -If you heat it up goes to liquid, cool down gets into gel -Similar to agar but it is the purified sugar component of agar -control shape of it
lithotrophic photoautotrophs
-Algae, photosynthetic bacteria -they can synthesize all of their metabolic and structural needs from inorganic nutrients
stab cultures
-Anaerobic media -Because obligate anaerobes require special culture conditions in that their cells must be protected from free oxygen, they are introduced into the anoxic (oxygen free) depths of solid media
Reducing media
-Anaerobic media -Special culturing medium containing compounds that combine with free oxygen and remove it from the medium
What is the difference between antiseptic and disinfectants?
-Antiseptic act on living organisms and disinfectants act on non living organisms -Disinfectants are more concentrated or can be left on a surface for longer periods of time
lithotrophs
-Autotrophic organisms -they acquire electrons from inorganic molecules
Organisms can be categorized into two broad groups based on their source carbon:
-Autotrophs -heterotrophs
Examples of of -stasis or -static
-Bacteriostatic -Fungistatic -Virustatic
Carotenoids
-Because singlet oxygen is also photochemically produced by the reaction of oxygen and light -Phototrophic microorganisms often contain this pigment (carotenoids) -Pigment that prevent toxicity by removing the excess energy of singlet oxygen
quorum sensing
-Biofilms often form as a result of this process -In which microorganisms respond to the density of nearby microorganisms by utilizing signal and receptor -Regulate genes in cells
Moist Heat
-Boiling 10 minutes at 100*C, denatures proteins and destroys membranes, disinfection of baby bottls and sanitization of restaurant cookware and tableware -Autoclaving 15 minutes at 121*C, denatures proteins and destroys membranes, sterilization of medical and lab supplies, pressure cookers, sterilization of canned food -Ulrta-high temp sterlization 1-3 seconds at 140*C, denatures proteins and destroys membranes, sterilization of dairy
Colony-forming unit
-CFU -A single cell or group of realted cells that produce the colony -"parent of the colony" -Progenitor is termed a CFU
The solely source of carbon for autrotophs is_, thus they do not need to_
-CO2 -not acquire carbon from organic compounds from other organisms
autrotophs take carbon from_and make their_
-CO2 -own chains of carbon
What does have aerobes to contrast the effects of perioxide anion?
-Catalase (converts hydrogen perioxide in water and molecular oxygen) -Peroxidase (breaks down hydrogen perioxide without forming oxygen, using a reducing agent like NADH ) -both enzymes that detoxify perioxide anion
what is the importance of genetic engineering in producing insulin?
-Codon w/ 3 nucleotides gives you an amino acid, which is universal -Universal: A codon always codes the same amino acid in all organism -So we can get human insulin DNA in regardless what organism we put it in, that is what will be transcribed into mRNA Human insulin and then into human insulin protein (enzyme) -we can put in other organism to get human insulin, does not matter what organism it is introduced
MacConkey agar
-Complex media -Selects for Gram Negative -Differentiates between Lactose fermenters.
What are the electronic counters?
-Coulter counter -Flow cytometry
Microscopic counts
-Count microorganisms directly from a microscope -stained prokaryotes and large eukaryotes -sample placed on cell counter, count bacteria in several of the large squares and then calculate the mean number of bacteria per square -No. bacteria per squareX 25 squares= no. of bacteria per 0.02mm^3 -No of bacteria per 0.02mm^3X 50=no. of bacteria per mm^3 -No of bacteria per mm^3X1000= no. of bacteria per cm^3 (mL)
what two characteristics of DNA are used in gel electrophoresis? Describe what happen to it for having this characteristics in this technique
-DNA has negative charge; drawn by electric current toward positive electrode -Smaller fragments migrate faster and further than larger ones (determine size by distance it travels comparing to distance traveled by standard DNA fragments of known sizes)
In what 2 processes ligase is involved?
-DNA replication during formation of lagging strand -In combining DNA fragments created by restriction enzymes in recombinant DNA technology
central dogma of genetics
-DNA transcribed to RNA. -mRNA translated to form Polypeptides
What are the types of media?
-Defined media -complex media -selective media -Differential media -Anaerobic media
With the agarose gel electrophoresis you can determine_
-Different rates of movement depends on size -So compare the size of DNA fragments -How many pieces of DNA within the sample
Membrane Filtration
-Direct method of estimating population size in which a large sample is poured through a filter small enough to trap cells -Used when population density is small -Colonies, after being filtered and incubated in solid medium, are counted -Equal to CFUs in the original sample
what is the result of the microbial growth?
-Discrete colony -Biofilm
Cold enrichment
-Enrich culture with cold tolerant microorganisms -Incubation of a specimen in a refrigerator to enhance the growth of col-tolerant species
PCR is critical to amplify DNA in variety of situations:
-Epidemiologists use to amplify genome of unknown pathogen (SARS->severe acute respiratory system) -Amplify DNA from Bacillus anthracis spores in 2001 to identify source of spores. -AZ Office of public health microbiology: 15 different PCR tests for potential pathogens
because of the rapidly reproduction of microorganisms, how laboratory personal know how many bacteria are in the medium?
-Estimate the number of cells in a population by counting the number in a small, representative sample, and then multiplying to estimate the number in the whole specimen
Viable plate count
-Estimation of the size of a microbial population based upon the number of colonies formed when diluted samples are plated onto agar media -plates with 25-250 colonies and multiply the number by the reciprocal of the dilution to estimate the number of bacteria per ml in original culture
Germicides include_
-Ethylene oxide -Prophylene oxide -Aldehydes
why the eukaryotic mRNA made by reverse transcriptase makes possibel for the prokaryotes to produce eukaryotic proteins?
-Eukaryotic DNA cannot be expressed by prokaryotic cells because they cannot remove introns presented in eukaryotic pre-mRNA -Since eukaryotic mRNA has already been processed to remove introns, cDNA produced from it lacks noncoding sequences -Scientists can successfully insert cDNA into prokaryotic cells to produce eukaryotic proteins
Defined media
-Exact chemical composition is known -also called synthetic medium
Log phase is_or represented in a graph as_; death is_or represented in a graph as_; stationary is represented in a graph as_; lag is represented in a graph as_
-Exponential -increasing -decline -declining or lowering -horizontal line (no change) -horizontal line (no change)
what was the principal source of insulin for the treatment of diabetes during 60 years? How the insulin was introduced in the human?
-For 60 years cows and pigs were used as principal source of insulin. -Injected into humans.
Genetic method of quantitation
-For bacteria and archea that cannot be grown in laboratory -Isolate DNA sequences representing unculturable prokaryotic species using genetic technique such as polymerase chain reaction (PCR) and hybridization of DNA that codes for ribosomal RNA
Superoxide radical
-Form during the incomplete reduction of O2 during electron transport in aerobes and during metabolism by anaerobes in the presence of oxygen -Solution to it: superoxide dismutases (produced by aerobes) to detoxify
what are some of the characteristics of the bacteria that tell us that it received the vector with the gene of interest?
-Genetic markers: 1. antibiotic resistance 2. code for enzymes that metabolize a unique nutrient 3. radioactive or fluorescent labels
genome mapping (definition and what involves)
-Genetic sequencing -involves locating genes on a nucleic acid molecule
What are some of the things that genetic engineering can produce?
-Genetically modified plants and corps -Increase growth in animals -Medicine production in microorganisms at a faster and in more quantities -Create plastics that do not rely on petroleum, genetically modified organism that can make the products -Create biodiesel
what were the two problems of using cow and pig insulin? Explain why
-Growing number of diabetics: So the process of obtaining insulin from cows and pigs was a very difficult and not efficient process that did not met the demand for insulin -Allergic reactions: Because the insulin obtained was the cow and pig version of insulin, which sometimes the body did not accept it
serial dilution
-Happens before viable plate counts -stepwise dilution of a liquid culture to low the number of cells in the sample
organotrophs
-Heterotrophs -They acquire electrons from the same organic molecules that provide them carbon
Dry Heat
-Hot air 2 hrs at 160*C or 1hr at 171*C, denatures proteins, destroys membranse, oxidizes metabolic compounds, sterilization of water-sensitive materials such as powders, oils and metals -Incineration, 1 sec at more than 1000*C, oxidizes everything completely, sterilization of inoculating loops, flammable contaminated medical waste, and diseased carcasses
what is the first genetically engineered drug approved by FDA? in what year?
-Humulin -1982
limiting nutrient
-Hydrogen is never a limiting nutrient -metabolism is never interrupted by a lack of hydrogen
Perioxide amino
-Hydrogen peroxide formed during reactions catalyzed by superoxide dismutase (and during other metabolic reactions) contains perioxide anion
How osmotic pressure can affect the cell?
-If cell put in an hypotonic solution, it is swells up or burst in the case it does not have cell wall -If cell placed in hypertonic solution, it loses water into the surrounding solution. Such cell can die of crenation or shriveling of its cytoplasm -Osmotic pressure restricts organisms to certain environments
How genetic engineering uses gel electrophoresis?
-In genetic engineering, scientists use the technique to isolate fragments of DNA molecules that can then be inserted into vectors, multiplied by PCR, or preserved in a gene library.
what is the treatment for diabetes Type I? why?
-Insulin injections -Type I diabetes does not make this hormone (within b cells in pancreas) that controls glucose levels in blood, so the person needs to inject it
How many times a gene should be introduced in the gene therapy? Thus this method will be long term or short term?
-Introduce gene successfully only once, so patient can make defective protein in a good way -long term
what other type of vaccine is found? (possible cure to malaria)
-Involves producing a recombinant plasmid carrying a gene from a pathogen and injecting the plasmid into a human, whose body then synthesize polypeptide characteristics of the pathogen -Polypeptides stimulates immunological memory within the human body, readying it to mount a vigorous immune response and prevent infection should it be subsequently be exposed to the real pathogen
Example of antisepsis
-Iodine -Alcohol
Flow cytometry
-Is a variation of counting with a Coulter counter -uses a light-sensitive detector to record changes in light transmission through a tube as cells pass -Count fluorescent dyed or tagged organisms
what scientists do in recombinant DNA technology?
-Isolate specific genes from a cell -Manipulate in vitro -Insert it into the genome of almost any kind of recipient organism
Osmotic pressure
-It is the pressure exerted on a semipermeable membrane by a solution containing solutes that cannot freely cross the membrane -Related to the concentration of dissolved molecules and ions in a solution
Dry weight
-Measure abundance of particularly filamentous microorganisms -These organisms filtered from their culture medium, dried, and weighted -Suitable for broth cultures
spectrophotometer
-Measures amount of microorganism by the method of turbidity -Measures the amount of light transmitted through a culture under standardized conditions -The greater the concentration in the broth, the more light will be absorbed and scattered, and the less light will pass through and strike a light-sensitive detector
what methods are used in DNA fingerprinting by scientists and_investigators?
-Medical laboratory technicians and forensic investigators use gel electrophoresis and Southern blotting for so-called genetic fingerprinting or DNA fingerprinting
Thermoduric organisms
-Mesophiles that can survive brief periods at higher temperatures
Polymerase Chain Reaction
-Method to amplify a specified region of DNA. -is a technique by which scientists produce a large number of identical molecules of DNA in vitro.
barophiles
-Microorganism requiring the extreme hydrostatic pressure found at great depth below the surface of water (ocean) -Their membranes depend on the high pressure to maintain the 3-dimensional shape
Obligate anaerobes
-Microorganism that cannot tolerate oxygen as the final electron acceptor of the electron transport chain -Oxygen is deadly poison to them
Singlet oxygen
-Molecular oxygen with electrons that have been boosted into a higher energy state, during aerobic metabolism -Very reactive oxidizing agent -Used by phagocitic cells to oxidize pathogens
why agar is useful compound in microbiology?
-Most microbes cannot digest agar (remains solid) -Powdered agar dissolves in water at 100degree C (temperature that most nutrients remain undamaged) -Agar solidifies at temperatures below 40 degree C (nutrients can be added without having to freezing them, cooling liquid agar can be poured to bacteria) -Solid agar does not melt below 100 degree C (culture many thermophiles)
binary fission
-Most unicellular microorganisms reproduce -process in which a cell grows to twice its normal size and divides in half to produce 2 daughter cells of equal size
The tools used by recombinant DNA technology are_(4)
-Mutagens -reverse transcriptase -Restriction enzymes -vectors
How can microorganisms survive to without water?
-Myocobacterium tuberculosis has cell walls that retain water -spores and cysts (in suspended animation)
What are the classification of pH range?
-Neutrophiles -Acidophiles -Alkalinophiles
Genetic screening involves the screening of_
-Newborn screening -Screening prospective parents and fetuses for inherited diseases caused by mutations. -Look for diseases in the future
Vector
-Nucleic acid molecules (DNA or RNA) that deliver a gene (gene of interest) into a cell -is a small DNA molecule (such as a viral genome, transposon, or plasmid) that carries a particular gene and a recognizable gene marker into a cell so that the cell will develop a new phenotype
What are some common complex media?
-Nutrient broth -Trypicase soy agar -MacConkey agar
autotroph
-Organism that utilize an inorganic source of carbon (carbon dioxide) as their sole source of carbon -"feed themselves"
chemotrophs
-Organisms that acquire energy from redox reactions involving inorganic and organic chemicals -aerobic respiration, anaerobic respiration, and fermentation depending on the final electron acceptor
complex media
-Partial digests so composition is not known. (contain nutrients digested and unknown because partial digestion releases many different chemicals in a variety of concentrations) -Supports wider variety of microbes.
Examples of disinfection
-Phenolics -alcohols -aldehydes -surfactants
Organism can be categorized based on their carbon and energy sources into one of four basic groups:
-Photoautotrophs -Chemoautotrops -Photoheterotrophs -Chemoheterotrophs
Mutagens (definition)
-Physical and chemical agents that produce mutations -agents used to create changes in a microbe's genome to effect desired changes in the microbe's phenotype
Gene of interest
-Piece of information (piece of interest DNA) within a huge set of information (genome) -The piece of genetically information that we want to introduce in the plasmid
Examples of aseptic
-Preparation of surgical field -Hand-washing -Flame sterilization of laboratory equipment
What are the 4 overlapping classifications of temperature in microorganisms ?
-Psychrophiles -Mesophiles -Thermophiles -Hyperthermophiles
Medical diagnoses
-Recombinant DNA techniques (PCR) are used for diagnostic applications -Patient specimens can be examined for the presence of gene sequences unique to certain pathogens
any molecule that is protein can be make by_
-Recombinant DNA technology -After inserting gene in bacteria, Grow many bacteria to produce a lot of the product
what is a technique to do slow down cells metabolism?
-Refrigeration (shorts periods of time) Long periods of time are: -Deep-freezing: freezing the cells at temperatures from -50degree C to -95 degree C -lyophilization: involves removing water from a frozen culture using an intense vacuum-> ice sublimates (becomes gas) and is removing from cells without permanently damaging cellular structures and chemicals
Describe how to change penicillium using mutagens
-Researchers exposed the fungus Penicillium to mutagenic agents and then selected strains that produce greater amounts of penicillin. -for the goal to make a strain of penicillium that can make more penicillin, more quickly or variant -We don't know where mutagens change, but if mold does not grow-> it did not grow -If it grows we could get a strain that does this things, so we can cultivate it and make more of this molds to produce more penicillia -BY IMPROVING PHENOTYPE OR PHYSICAL CHARACTERISTICS
hydroxyl radical
-Result from ionizing radiation and from the incomplete reduction of hydrogen perioxide
Protein synthesis (example, and benefits)
-Scientists have inserted genes for insulin and other proteins into bacteria and yeast cells so that the cells synthesize these proteins in vast quantities. -Genetically engineered proteins are safer and less expensive than proteins isolated from donated blood or from animals.
How scientists use restriction enzymes?
-Scientists use restriction enzymes to cut DNA at locations with specific and usually palindromic nucleotide sequences called restriction sites. -To get specific little piece of DNA (gene of interest)
How scientists use mutagens? After using mutagens, what scientist do?
-Scientists utilize mutagens to create changes in microbes' genomes so phenotypes are changed -They then select for and culture cells with characteristics considered beneficial for a given biotechnology application
When using mutagens in recombinant DNA technology, scientists have to_. Today _instead of dealing with entire organisms
-Select for and culture cells with beneficial characteristics -Today, mutated genes alone can be isolated
What are the 4 toxic forms of oxygen?
-Singlet oxygen (1^O2) -Superoxide radical (O2-) -Perioxide anion (O2^2-) -Hydroxyl radical (OH)
what are the useful properties of the vector? (4)
-Small enough to manipulate in a lab -Survive inside cells (does not degrade becasue are very stable) -Contain recognizable genetic marker (researchers can identify the cells that have received the vector) -Ensure genetic expression of gene (have gene code correctly so you get what you want, which is a protein/ include promoters)
Denaturation (PCR)
-Step 1 -separation of the two strands of DNA -Using high temperatures: 94 degree (boiling) to denature hydrogen-bonds between base pairs bases in two strands
Sticky end cut
-Sticky end restriction cuts the two strands in a staggered way (NOT IN MIDDLE) with complementary "sticky ends" -Restriction enzymes cuts two strands of DNA producing fragments that terminate in mortise-like sticky ends -Easier to make DNA recombinant than blunt end fragments because they are sticky; however they only bind to complementary, sticky-ended fragments produced by the same restriction enzyme
Antigen (definition, ex, what they cause in contact with human body)
-Substance that stimulates bodies immune system. -foreign substance such as weakened bacteria, viruses, and toxins that simulate the body's immune system to respond to and subsequently remember these foreign materials
what are the successful treatments of gene therapy?
-Successfully treated patients with severe combined immunodeficiency disease -Others that may respond well - cystic fibrosis, sickle cell anemia, some types of hemophilia, some types of diabetes
-cide -cidal
-Suffixes indicating destruction of a type of microbe
Xenotransplants (definition and solve which problem?)
-Technique involving recombinant DNA technology in which human genes are inserted into animal to produce cells, tissues or organs that are then introduced into the human body -solve the problem of transplant recipient rejection for being a foreign tissue
Categories of bacterial colonies?
-Texture -Pigmentation -Optical property -size -shape -Margin -elevation -appearance
Turbidity
-The greater the bacterial population, the more turbid a broth will be -Measure the change in turbidity using spectrophotometer -Transmission of light is inversely proportionally to the population size -The larger the population grows, the less light will reach the detector -Must have of concentration 1 million per milimiter and cells should be suspended uniformly in the medium
How thioglycollate growth medium works?
-The surface is exposed to atmospheric oxygen and is aerobic -Oxygen concentration decreases with depth; the bottom of the tube is anaerobic
How can oxygen be essential for one group of organisms and yet be fatal toxin for others?
-The toxic forms of oxygen are those that are highly reactive -They are toxic for the same reason that oxygen is the final electron acceptor for aerobes: they are excellent oxidizing agents, so they steal electrons from other compounds -The resulting chain of virgorous oxidations causes irreparable damage to cells by oxidizing important compounds, including proteins and lipids
Are psychorphiles pathogenic? where they can be found?
-They are not pathogenic because they cannot stand human body temperature but they can cause food spoilage in refrigerators -Found in ice, snowfield, and cold water
Encrichment culture
-To isolate potentially important microbes that might be otherwise overlooked -Technique used to enhance the growth of less abundant microorganisms by using a selectively medium
Indirect 3 methods of quantifying bacterial numbers.
-Turbidity -Dry weight -Metabolic activity
Which diabetes is acquired after born? what are some of the factors that influence if a person gets diabetes?
-Type II -can get by genetics, depending on ancestry, diet, exercise level
Recombinant DNA technology (definition)
-Type of biotechnology (sciences) -Intentionally modifying genomes of organisms, by natural and artificial processes, for practical purposes -change genotypes and phenotypes of organisms
subunit vaccines (definition and benefit)
-Type of vaccine developed using recombinant DNA technology, which exposes the recipient's immune system to a pathogen's antigens but not the pathogen itself -Useful in safely protecting against pathogens that either cannot be cultures or cause incurable fatal diseases
what is the typical delivery system for gene therapy? How this method is called?
-Typically engineered virus is used as delivery system. -transduction
metabolic activity
-Under standard temperature conditions -the rate at which a population of cells utilizes nutrients and produces wastes is dependent on their number -Once established the metabolic rate->indirectly estimate the number of cells in a culture by measuring changes in such things as nutrient utilization, waste production, or pH
What does Reverse transcriptase do? How is the flow of information by this enzyme compared to the normal flow of genetic information?
-Uses RNA template (mRNA) to transcribe molecule of cDNA (complementary DNA) -Flow of genetic information in the opposite direction form the flow in conventional transcription
What does vaccines contain?
-Vaccines often contain weak (attenuated) forms of pathogen or killed. -use a portion of a pathogen rather than the pathogen itself -antigens
what happens when vaccines are injected in humans?
-When the vectors, or the polypeptides they produce, are injected into a human, the body's immune system is exposed to and reacts against relatively harmless antigens instead of the potentially harmful pathogen. -Immune system builds antibodies against that specific disease by being exposed to antigens
What are the 3 things that all cells need for metabolism?
-a carbon source -a source of energy -source of electron or hydrogen atoms
What is the function of matrix within biofilms?
-a matrix adheres cells to one another -sticks a biofilm to its substrate -forms microenvironments within a biofilm -sequester nutrients -may protect individuals in a biofilm from environmental stresses -concentrate and conserve digestive enzymes -organize the biofilm community, allowing individual members to display metabolic and structural traits different from those expressed by those expressed by the same cells living individually (assume different roles)
Isolation techniques only work well if_
-a relatively large number of CFUs of the organism of interest are present in the initial sample -if the medium supports the growth of that microbe
antimicrobials
-act against cell walls, cell membranes, protein sythesis, and DNA transcription and replication -intermediate to low activy -disinfectants and treatment of infectious diseases
Agricultural uses of recombinant DNA technology include: (give examples of each) (5)
-advances in herbicide resistance (Gene from Salmonella (Agrobacterium) impacts resistance to Roundup) -salt tolerance (Gene for salt tolerance inserted into tomato and canola plants. These plants grow in produce fruit and remove salt from soil) -freeze resistance (Crops sprayed with genetically modified bacteria (pseudomonas) can tolerate mild freezes) -pest resistance (Toxin from Bacillus thuringiensis (Bt Toxin) kills insects. Bt-toxin gene inserted into cotton and corn.) -as well as improvements in nutritional value and yield. (Ripe tomatoes - gene for pectin breakdown surpressed. and rBGH - 10% more milk with reduced fat content.)
examples of chemoheterotrophs
-animals -fungi -other protozoa -some bacteria and yeast
Among the ethical and safety issues surrounding recombinant DNA technology are
-are concerns over the accidental release of altered organisms into the environment -the ethics of altering animals for human use -the potential for creating genetically modified biological weapons.
Restriction enzymes
-are enzymes used by bacterial cells to protect against phages (virus) by cutting phage DNA into nonfunctional pieces. -Bacterial enzymes that cut DNA molecules only at specific locations (restriction sites)
pure cultures
-axenic -cultures composed of cells arising from a single progenitor
Examples of -cide or -cidal
-bactericide -fungicide -germicide -virucide
why aerobes can resist superoxide radical an anaerobes cannot?
-because aerobes produce superoxide dismutases which detoxify of superoxide radical by combinig it with protons of hydrogen peroxide -Anaerobes lack these and die as a result of the oxidizing reactions
why complex media has an advantage over defined media?
-because complex medium contains a variety of nutrients, including growth factors, it can support a wider variety of different microorganisms -Complex media used to culture organisms whose exact nutritional needs are unknown
Why the use of petri plates is not appropiate for anaerobic media? How this can be solved?
-because it present a problem to anaerobes because each dish has a loose-fitting lid that allows the entry of air -By putting anaerobes in petri plates with sealable containers containing reducing chemicals
why gene therapy has proven difficult in practice?
-because of unexpected results -Patients' human system react uncontrollably to the presence of vectors, resulting in death (negatively)
Acidic substances have a pH_7 and alkaline (basic) substances have a pH_7. Neutral substances are at_
-below -higher -7.0
how can you see DNA in a very visual way? who (what organization) uses this method?
-by Agarose Gel Electrophoresis -CIA
Complemetary DNA (abbreviation, who makes it by what process, definition)
-cDNA -Reverse transcriptase by transcribing DNA nucleotides from an RNA template -so called because it is complementary to an RNA template.
During commercial sterilization of _, the process does not kill all_, but this is not a problem because_
-canned food -hyperthermophilic microbes -They do not cause diseases and they cannot grow and spoil food at ambient temperatures
all cells require source of_,_,and_
-carbon -electrons -energy
Together what elements make up 95% of the dry weight of cells? what other elements constitute the rest?
-carbon, hydrogen, oxygen, and nitrogen -phosphorus, sulfur, calcium, maganese, magnesium, copper, iron, and a few other elements
Categories of source of energy is based on whether organisms use _for such cellular processes as_
-chemical or light as a source of energy -anabolism, intracellular transport, and motility
Categories of source of energy:
-chemotrophs -phototrophs
Edible vaccines
-chew leaf to get vaccine and use plants to provide vaccines instead of shot -Produced by recombinant approach -Made by introducing genes coding for antigenic proteins of pathogens into common fruit or vegetables -The immune system of people and animals that such altered produced would develop immunological memory against the pathogen -Advantages: being painless, easy to administer, vaccination would not require a visit to a health care provider
turbid
-cloudiness of a broth when bacteria reproduces in a broth culture -indicates that microorganisms are growing in the media
gene library
-collection of bacterial or phage clones (identical descendants) each of which contains a portion of the genetic material of interest -may contain clones with all the genes of a single chromosome or of the set of cDNA (complementary DNA) that is complementary to an organism's mRNA -Saves time and effort required to isolate an specific gene
What are the distinctive characteristics of colonies that are used to identify different microbial species ?
-color -shape -size -elevation -texture -appearance of the colony's margin (edge)
nutrient broth
-common media -contains powdered beef extract and peptones dissolved in water
Biofilms are an example of_. They are considered to be a primary_
-complex relationships among numerous microorganisms, often different species, attached to surfaces -residence of microorganisms in nature
DNA fingerprinting is used in _to establish identity by_
-criminal system to establish identity. -Isolating genetic material from different samples to link with specific individual (never 100%)
candle jars
-culture plates are sealed in a jar along with a lit candle -Flame consume O2, replacing it with CO2 -Create environment ideal for aerotolerant anaerobes, microaerophiles, and capnophiles
Surfactants (soaps and detergents)
-decrease surface tension of water and disrupt cell membranes -low level of activity -soaps; degerming; detergents; antiseptic
Modifications to disinfection include:
-degermining -sanitization -pasuterization
Enzymes
-denature proteins -high against target substrate -removal of prions on medical instruments
Aldehydes (glutaraldehyde and formaldehyde)
-denature proteins -high level of activity -disinfectant and emabalming fluid
Gaseous agents (ethylene oxide, propylene oxide, and beta-propiolactone)
-denature proteins -high level of activity -sterilization of heat and water sensitive objects
Heavy metals (arsenic, zinc, mercury, sliver, copper)
-denature proteins -low level of activity -fugistats in paints; silver nitrate cream; surgical dressings, burn creams and catheters, copper, algicide in water reservoirs, swimming pools, and aquariums
Alcohols
-denature proteins and disrupt cell membranes -intermediate level of activity -disinfectans, antiseptics, and as a solvent in tinctures -denaturation of proteins requires water, so solutions of 70% to 90% are typically used to control microbes
phenolics (chemically altered phenol)
-denatures proteins and disrupts cell membranes -intermediate level of activity -disinfectans and antiseptics
phenols (carbolic acids)
-denatures proteins and disrupts cell memebrane -intermediate level of activity -original surgical antiseptic; now relplaced by less odorous and injurious phenolics
Oxidizing agents (peroxides, ozone, and peracetic acid)
-denatures proteins by oxidation -high level of activity -disinfectants, antiseptics for deep wounds, water purification, and sterilization of food-processing and medical equipment
Coulter counter
-device that directly counts cells as they interrupt an electrical current flowing across a narrow tube held in front of an electronic detector -large numbers of yeast, unicellular algae, and protozoa (no good for bacteria)
animal and cell culture
-disease must be grown on an animal (leprosy and syphilis) -Grow them within living cells (bird eggs and cultures of living cells)
How can you create a solid media?
-dissolve 1.5% agar into hot broth -pour the liquid mixture into an appropiate vessel -allow it to cool provides a solid surface to support colonial growth
pH and temperature important for bacteria because these affect:
-enzymes -proteins (pH) -Nucleic acids (pH) -Also affects the membrane (phospholipi bilayer) (temperature)
standard precautions
-established by Centers for Disease Control and Prevention (CDC) -Guidelines to protect health care professional from contamination by pathogens
what is found in the vitro before PCR starts? (necessary reagents)
-excess of DNA primers (synthesized such that they are complementary to the nucleotide sequences near the ends of the target DNA) -DNA polymerase -4 deoxyribosenucloeotide triphosphates (dNTPs)-> A, T, G, C -DNA template -buffer
Osmotic Pressure
-exposure to hypertonic solutions -inhibits metabolism -preservation of food (high salt, high sugar)
Biofilms develop_
-extracellular matrix, composed of DNA, proteins, and primairly the tangled fibers of polysaccharides of the cells' glycocalyces
filtration
-filter retains microbes -physically seperates microbes from air and liquids -sterilization of air and heat-sensitive opthalmic and enzymatic solutions, vaccines, and antibiotics
DNA fingerprinting
-genetic fingerprinting -Technique in which identifies unique sequences of DNA to: determine paternity; connect blood, semen, or skin cells to suspects in criminal investigations; or identify pathogens -to identify individuals or organisms by their unique DNA sequences.
Growth curve
-graph that compares number of organisms in growing population versus time. -With a logarithmic scale (each division 10 times larger than previous)
The reproduction of individual microorganisms results in the_of_
-growth -colony or biofilm
Examples of of degerming
-handwashing -alcohols swabbing at site of injection
Hydrogen is essential for_
-hydrogen bonding -electron transfer
Temperatures affects the bonds_
-hydrogen bonds of proteins
Solutions with greater concentrations of such solutes are_ relatively to those with a lower solute concentration, which are_
-hypertonic -hypotonic
Where thermophiles can be found? what is one of the members?
-in habitats such as compost piles and hot springs -Archaea
What diseases are caused by genetic mutations?
-inherited forms of breast cancer -Huntington's disease
Freezing
-inhibits metabolism -long-term food preservation, drugs and cultures
mRNA of eukaryotes have_removed, so can be_
-introns -can be cloned into prokaryotic cells -Since eukaryotic cDNA lacks noncoding sequences, scientists can insert it into prokaryotic cells, making it possible for the prokaryotes to produce eukaryotic proteins such as human growth factor, insulin, and blood-clotting factors.
Non-ionizing radiation
-irradiation with 260-nm-wavelength radiation -formation of thymine dimers inhibits DNA transcription and replication -disinfection and sterlization of surfaces of transparent fluids and gases
Biotechnology
-is the use of microorganisms to make practical products -such as bread, wine, paper, and antibiotics.
Temperatures also effect the sensitive_, such as those that are _
-lipids -components of the membranes of the cells and organelles
Site to be treated
-living tissue vs. inanimate; harsh chemicals and extreme heat cannot be used on humans, animals, and fagile objects; can be used on surfaces, surgical equipment etc. -internal vs. external tissues -number of microbes present
Thermophiles are temperature_, Hypermophoes are _, Mesophiles are_, and psychrophiles are_
-loving -extreme temperature loving -so kind of love it (middle) -psychoes that like very cold temperatures
what is another use of genomics?
-make gene maps of organisms -is to relate DNA sequence data to protein function.
Microorganism must be in a _environment to be metabolically active.
-moist
Organisms use a variety of _for their energy needs and to build _and _
-nutrients -organic molecules and cellular structures
growth factor
-organic chemical such as vitamins required in very small amounts for metabolism -Organism need them because they cannot synthesize
fastidious
-organisms that require a relatively large number of growth factors -Such organisms may be used as living assays for the presence of growth factors (know if an specific growth factor and its quantity is present in the sample)
phototrophs
-organisms that use light as their energy source
Examples of pausterization
-pausterized milk and fruit juices
Restriction enzyme cut_bonds. Ligase _
-phosphodiester -seal gaps (paste) DNA by creating phosphodiester bond between the fragments of DNA
what is the usage of phosphorus in cells?
-phospholipid bilayer -DNA -RNA -ATP -Proteins
Scientists use a variety of _ to manipulate_ and create ._
-physical agents, naturally occurring enzymes, and synthetic molecules -genes and genomes -gene libraries
examples of photoautrophs
-plants -some protozoa -algae -cyanobacteria -Green sulfur bacteria and purple sulfur bacteria
Where is the environmental species are taken? where is clinical species are taken? what is another source of the inoculum?
-ponds, streams, soils, and air -taken from patients and handled in ways that facilitate the examination of or testing for the presence of microorganisms -Culture originally grown from an environmental or clinical specimen and maintained storage in a lab
Halogens (iodine, chlorine, bromine, and flourine)
-presumably denature proteins -intermediate level of activity -disinfectants, antiseptics, and water purification
A medium must have_to grow and multiply microorganisms
-provide essential nutrients -water -appropriate oxygen level -required physical conditions (pH, osmotic pressure, and temperature)
Stab
-put stuff inside the media and stab it into the media (reap surface) -anaerobic media
rBGH
-rBST -recombinant cow hormone -produce more milk, and less fat content
Diabetes is a defect in how the human_
-regulates glucose or sugar in blood -Defect in the pathway that regulate glucose
PCR is an_process that_
-repetitive -that alternately separates and replicates the two strands of DNA.
Blunt end cut
-restriction enzymes looks for specific sequence in both strands and cuts in the middle of the sequence (double stranded sequence) -Results when restriction enzyme cur both strands of DNA at the same point->blunt ends -Combined to other fragments of DNA easier because they are not specific. However, difficult to do because they are no sticky
Ionizing radiation (electron beams, gamma rays, X rays)
-seconds to hours of exposure (depending on wavelength) -Destroys DNA -Sterilization of medical and laboratory equipment and preservation of food
What are the physical categories to identify and differentiate bacteria?
-shape -Margin -elevation -size -texture -appearance -pigmentation -optical property
Defect in individual genes result in_. This diseases are caused by_
-sickness -point mutation that has occur within their genetic material, so they change one amino acid of a protein in our body and does not work well
Determine how fast a DNA fragment moves, would determine its_. Explain if DNA is short or long what happens
-size -if DNA short, less nucleotides in the chain, so move faster and moves a greater distance -If DNA long, more nucleotides in the chain, so move slower and move less distance
To store living cells, what a scientists do?
-slows the cells' metabolism to prevent the excessive accumulation of waste products and the exhaustion of all nutrients in a medium
Germistatic agents include_
-some chemicals -refrigeration -freezing
Most probable number
-statistical estimation of the size of a microbial population based upon the dilution of a sample required to eliminate microbial growth -Based on the more bacteria are in the sample, the more dilutions are required to reduce their number to zero -95% correct -use 5 tubes inoculated -Used for microorganisms that do not grow on solid media and samples of wastewater, having too few to count or too numerous to count
Sterilization is typically achieved by _
-steam under pressure -incineration -ethylene oxide gas
Priming (PCR)
-step 2 also called annealing -addition of nucleotide mixture followed by cooling (65 degree C) -DNA polymerase: Cannot add 1st letter/nucleotide to synthesize strand->we use a short strand of DNA (PRIMER) that we know exactly what it is -Cold temperature to bind primer to form base pairs with the strands (strands are more likely to bind to primers than to one another) -Primers determine stop and start part that we want to make more copies (region)->copy only what is between the two primers (region) -Primers provide DNA polymerase with the 3' hydroxyl group it requires for DNA synthesis
Extension (PCR)
-step 3 -heating (72 degree C) to increase the rate of replication by DNA polymerase -DNA polymerase add nucleotides to the end of the primer (3' hydroxyl group) -It adds: dNTPs: building blocks of DNA (A,G,C,T) -5'->3' direction of DNA polymerase -DNA polymerase replicates each strand to produce more DNA
Erythropoietin
-stimulates blood (erythrocytes) production -athletes use them so their blood can carry more oxygen and they have better performance
What are the usages of sulfur in cell?
-sulfur-containing amino acids -disulfide bonds (protein tertiary structure) -Vitamins
What are the ways to treat the 4 toxic forms of oxygen in aerobes?
-superoxide dismutase -catalase -perioxidase -antioxidant (vitamin C and E) by providing electrons to reduce toxic forms of oxygen
What are the two types of beneficial relationships?
-synergisitc relationships -symbiotic relationships
Can you name four physical parameters that can affect growth of microbes?
-temperature -pH -Osmolarity -Pressure
nitrogen fixation
-the conversion of atmospheric nitrogen to ammonia -performed by cyanobacteria and Rhizobium -Organisms provide nitrogen in a usable form to other organism
Differential media are formulated such that either the presence of visible changes in _or differences in the_ help microbiologists differentiate among different kinds of bacteria growing in the medium
-the medium -appearance of colonies
Pour plate rather than reducing the number of microbes in _like in streak plate, It does the reduction_
-the plate -It does the reduction prior to putting in the plate
what are the ethical issues about genetic screening?
-the rights of governments, employers, or insurers to routinely screen people for certain diseases -the rights of individuals to refuse either screening or treatment for genetic disease -the rights of both institutions and individuals to privacy and confidentiality of genetic data.
restriction sites
-the specific location where restriction enzymes cut DNA molecules -specific nucleotide sequences, which are usually palindromes (have same sequence when read forward or backward)
what the gel electrophoresis involves? (describe what happens)
-the technique involves drawing DNA molecules, which have an overall negative charge, through a semisolid gel by an electric current toward the positive electrode within an electrophoresis chamber. -Smaller DNA fragments move faster and farther than larger ones.
generation time
-time is the time required for a bacterial cells to grow and divide -Time required for a population of cells to double.
Some opponents of recombinant DNA techniques argue that transgenic organisms could _
-trigger allergies or cause harmless organisms to become pathogenic -whereas others caution that the long-term effects of transgenic manipulations are unknown - that unforeseen problems arise from every new technology.
Personalized genomics
-use genetic screening -how likely are you to get a specific disease by percentages
what information can you obtain from gene maps?
-useful facts about metabolism and growth characteristics -potential relatedness to other microbes
semilogarithmic graph
-uses only one axis logarithmic in which it increases by 10 times -each division is 10 times larger than the preceding one -Solves problem of having too little or too many bacteria
How most of bacteria reproduce? How this is known?
-using binary fission -Logarithmic or Exponential growth
dessication (drying)
-varies with amount of water to be removed -inhibits metabolism -preservation of food
A vector includes_(types)
-viral genomes -transposons -plasmids
what are some growth factors for various microbes?
-vitamins -amino acids -purines -pyrimidines -cholesterol -NADH -Heme
Complex media is called like this because?
-we don't know the components within the media that are important for bacteria to grow, but it grows on it
Can microorganisms survive below the minimum growth temperature? If yes, why is called minimum growth temperature?
-yes -The minimum growth temperature is defined as the lowest temperature that supports metabolism. Many organisms can survive at low temperature but do not actively metabolize, grow, or reproduce
Which statement describes the citric acid cycle? -The citric acid cycle converts pyruvic acid to acetyl CoA. -The citric acid cycle produces some ATP and carbon dioxide in the mitochondrion of eukaryotes, but takes place in the cytoplasm of bacteria. -The citric acid cycle uses energy captured from electrons flowing to oxygen to produce most of the ATPs in cellular respiration. -The citric acid cycle splits glucose in half and produces 2 ATPs for each glucose. -The citric acid cycle joins 2 pyruvic acid molecules into a molecule of glucose.
...
genotype
...
regulator
...
What are four types of plasmids?
1) Fertility plasmids 2) Resistance factors 3) Bacteriocin factors 4) Virulence factors
What are the three steps of transcription?
1) Initiation 2 Elongation 3) Termination
What are two ways a transcript can be terminated?
1) Self termination 2) Enzyme dependent termination
Put the following enzyme reaction steps in order: 1.Binding of substrate to the active site 2.Dissociation 3.Product formation 4.Enzyme recovery 5.Formation of the enzyme-substrate complex
1, 5, 3, 2, 4
what are the three goals of Recombinant DNA technology?
1. Create organisms that synthesize products humans need. (Insulin produced by bacteria) 2. Eliminate undesirable phenotypic traits in humans, animals, plants, and microbes. (freeze tolerance or pest resistance/ cure children with genetic disorder) 3. Combine beneficial traits of two or more organisms to create valuable new organisms.
PCR is a Repetitive process consisting of three steps:
1. Denaturation 2. Priming 3. Extension
Explain how the Kirby Bauer (disk diffusion) test works
1. Have plate and swab test org onto plate 2. put disc with antibiotic or disinfectant on top of plate 3. incubate overnight 4. During incubation bacteria grow and disc with antibiotic/disinfectant diffuses onto plate 5. Determine effectiveness of the agent by looking at zones of inhibition. The bigger the zone, the better the killing
Recombinant approach within the vaccines->describe steps and example
1. Insert the gene that codes for a pathogen's antigens into a vector 2. Inject vector or Inject purified gene product (protein or portion of protein) 3. Thus the patient's immune system is exposed to a subunit of the pathogen (pathogne's antigens) but not pathogen itself Ex. Hep B vaccine.
List the steps of the overview of the methodology utilized in recombinant DNA technology
1. Isolate plasmid 2. Enzymatically cleave DNA intro fragments 3. Isolate fragment with the gene of interest 4. Insert gene into plasmid 5. Insert plasmid and gene into bacterium 6. Culture bacteria: a. Harvest copies of gene to insert into plants or animals-> Eliminate undesirable pehonyptic traits or Create beneficial combination of traits b. Harvest proteins coded by gene->Produce vaccines, antibiotics, hormones, or enzymes
what you get as a result in gel electrophoresis?
1. Number of different DNA's that are present 2. Sizes of DNA's 3. Quantity/ amount of given DNA fragment (staining-> tells us the amount of DNA present)
Transcription
1. Only one DNA strand is a template, only one gene transcribed at any given time. 2. Enzyme RNA polymerase binds to promoter on DNA then unzips the DNA molecule 3. triphosphate ribonucleotides align with their DNA compliments then RNA polymerase links them together, synthesizing RNA. (in eukaryotes it occurs in the membrane bound nucleus, in the prokaryotes it occurs in the cytosplasm)
Pharmaceutical and Therapeutic Applications (6)
1. Protein synthesis 2. Vaccines 3. Gene therapy 4. Genetic screening 5. Medical diagnosis 6. DNA fingerprinting
4 steps of binary fission
1. Replication of chromosomes (attachment to cytoplasmic membrane) 2.Cell elongates and growth between attachment sites pushes chromosomes apart 3. Cell forms new cytoplasmic membrane and wall (septum) across the midline 4. When the septum is completed, the daughter cells may remain attached or they may remain separate completely
Describe the steps used to make a recombinant vector
1. Restriction enzyme cuts both DNA molecule containing the gene of interest and the vector DNA into fragments with sticky ends 2. Ligase anneals the fragments to produce a recombinant plasmid 3. The recombinant plasmid has been inserted into a bacterial cell 4. The bacteria are grown on a medium containing the anitbiotic 5. Only those cells that contain the recombinant plasmid can grow in the medium
techniques to localize genes (gene mapping)
1. Restriction fragmentation (using restriction enzymes) 2. Fluorescent in situ hybridization (FISH)
Explain how the MIC (minimum inhibitory concentration) test works
1. Series of test tubes with increasing concentrations of antibiotic is prepared in the culture medium 2. Each tube is inoculated with the same concentration of a test organism 3. incubate 4. Look for growth measured in turbidity, only occurs in test tubes with antibiotic concentrations below the MIC 5. Streak test tubes without turbidity onto a media to determine if cells are killed or inhibited to determine the MBC (minimum bactericidal concentration)
Methods to take DNA or plasmid into bacteria
1. Transformation 2. Transduction 3. Conjugation
What is one of the various ways to perform pour-plate method?
1. an initial 1mL sample is mixed into 9.0mL of medium in a test tube. 2. After mixing, a new sample from this medium is then used to inoculate a second tube of liquid medium. 3. The process is repeated to establish a series of dilutions 4. Samples from the more diluted media are mixed in petri dishes with sterile, warm medium containing agar 5. After agar solidifies and cools down, the petri plates are incubated 6.Isolated colonies form in the dishes from CFUs that have been separated via the dilution series
steps to making new proteins transcription
1. enzyme "RNA polymerase" finds a place on the DNA nucleotide chain called a "promoter" which starts transcription 2. RNA polymerase unzips and unwinds the DNA 3. Triphosphate ribonucleiotides (3 phosphates on board) line up with their complementary bases (U with G, G with C) on the DNA strand those are the phosphate bonds that provide the energy 4. enzyme "RNA polymerase" links the ribonucleotide molecules together also known as "elongation" of the RNA Transcript
Phases of microbial growth
1. lag 2. log 3. Stationary 4. Death
three types of horizontal gene transfer
1. transformation 2. transduction 3. bacterial conjugation
Once solidified, agar will not melt at temperatures below ________.
100°C.
What are the standard operating conditions for the autoclave? What sort of items do you sterilize using the autoclave?
121 degrees C 15 minutes 15 psi used to sterilize media that we use to grow bacteria
Nitrogen makes up about_%of the dry weight of microbial cells
14
Pasteurization
15 seconds at 72*C, denatures proteins and destroys membranse, destruction of all pathogens and most spoilage microbes in dairy products, fruit juices, beer and wine
Since psychrophiles grow best at temperatures below______, a refrigerator would be the best environment for their growth.
15°C
Starting with a single parent cell, how many cells would there be after four rounds of binary fission? 4 8 12 16 32
16
What are the standard operating conditions for the hot air oven? What types of things do you sterilize using the hot air oven?
170 degrees C 3 hours empty test tubes
How many ATPs are required to produce one molecule of glucose? 9 18 6 36
18
what process substituted the method of taking insulin from cows and pigs? In what year?
1970's - New genetic techniques were being developed. Recombinant DNA technologies
How many cycles of the Calvin-Benson cycle are required to produce 1 molecule of glucose? 1 2 3 6
2
steps to making new proteins inside the ribosome: A site P site E site
2 subunits of ribosome one large, one small Smaller subunit has 3 sites A- Accommodation site, Charged tRNA comes in to site P- Polypeptide site - holds protein that is growing E - Exit site- discharges tRNA
If you begin with three cells, how many cells would you have after three rounds of division?
24
If a cell counter slide is determined to have a mean number of 20 bacterial cells per square, the total number of bacteria per ml of culture would be __________.
25,000,000
At which site of the DNA strand does the hydroxyl group attach?
3 prime end always has hydroxyl - this is where things will attach
Glycolysis involves the splitting of a glucose molecule and results in two molescules of pyruvic acid and a net gain of two ATP and two NADH molecules. How many stages and steps are in this process.
3 stages;10 steps
Each cycle of PCR consist of _
3 steps
Acceptor Stem
3' end of a tRNA molecule to whicha specific Amino Acid binds
Put the following steps of bacterial replication in order, starting from a parent cell. Cell elongation Septum formation Chromosome replication Separation of daughter cells
3, 1, 2, 4
Put the following steps of the electron transport system in order, starting with NADH: Electrons to coenzyme Q Electrons to the cytochrome complexes Electrons to flavoprotein Electrons to carbonate ion 3, 2, 1, 4 3, 1, 2, 4 4, 3, 1, 2 1, 2, 3, 4
3, 1, 2, 4
Based on the slide, how you classify human bacterial pathogens? 1. Thermoduric 2. Thermophile 3. Mesophile 4. Hyperthermophile 5. psychrophile
3. mesophile because body temperature is 37 degree C
when FDA was searching for the hGH, how many hits for recombinant did?
3000 hits for "recombinant"
The MPN method involves 15 tubes at different growth dilutions and it requires a____-hour incubation period.
48
A bacterial species has been determined to have a generation time of 30 minutes. If a microbiologist starts with an inoculum of 1000 cells/ml, and wants to grow it to a culture of 1,000,000 cells/ml, approximately how long should the culture be incubated?
5 hours
Which is better for killing, 100% or 80% alcohol and why?
60-80% because it stays on the surface longer and has a better chance of working, the higher the alcohol content, the quicker it evaporates
Which of the following equations represents photosynthesis? -C6H12O6 + 6O2 → 6CO2 + 6H2O -6CO2 + 6O2 → C6H12O6 + 6H2O -6CO2 + 6H2O → C6H12O6 + 6O2 -6H2O + 6O2 → C6H12O6 + 6CO2 -C6H12O6 + 6CO2 → 6O2 + 6H2O
6CO2 + 6H2O → C6H12O6 + 6O2 Photosynthesis requires carbon dioxide and water for the production of sugar and oxygen.
Prokaryotic Ribosomes
70S Ribosomes- based on their sedimentation rate in an ultracentrifuge- that consist of a Small and Large Subunit, and many polypeptides
Eukaryotic Ribosomes
80S Ribosomes that are larger, but also consist of a Small and Large Subunit, and many polypeptides
In a population of bacteria, how does presence of an antibiotic help resistant cells within that population? A. the antibiotic kills or inhibits competitors, allowing the resistant cell to grow without competition B. the antibiotic is metabolized by the resistant cell, providing more energy for growth C. the sensitive cells must devote energy to destroying the antibiotic, slowing their growth D. the antibiotic mutates sensitive cells, making them incapable of growing
A
In the agar diffusion method of studying antimicrobial action, the ____ is measured. A. diameter of the zone of inhibition B. diameter of the individual microbial colonies C. turbidity of the medium D. distance between the microbial colonies
A
Interferon is A. host specific B. virus specific C. both host and virus specific D. neither host nor virus specific
A
Of all the known antibiotics that have been identified in nature, ____ are clinically useful. A. <1% B. 8-10% C. 18-20% D. 25-30%
A
Semisynthetic antibiotics A. are natural antibiotics that have been chemically modified in the lab B. have an artificially constructed core that stimulates the production of "natural products" C. are found in nature but their rate of production is enhanced in the lab D. are natural antibiotics that have been purified by artificial means
A
Sulfamilamide is an analog of A. p-aminobenzoic acid B. folic acid C. sulfuric acid D. citric acid
A
The process by which macromolecules lose their structure and ability to function is called A. denaturation B. sterilization C. thermal death D. none of the above
A
The use of a HEPA filter in a biological safety cabinet is an application of filter sterilization using what type of filter? A. depth filter B. membrane filter C. nucleation track filter D. nucleospore filter
A
What effects would tetracycline likely have on an infecting bacterium? A. a reduction in protein synthesis by interfering with tRNA B. a weakened PG layer C. disruption of the cell membrane D. inability to replicate DNA by blocking DNA gyrase
A
Which chemotherapeutic agent interferes with the integrity of the bacterial cytoplasmic membrane? A. polymyxin B. streptomycin C. chloramphenicol D. tetracycline
A
Which is a mechanism that enables a bacterial cell to overcome the effects of sulfonamides? A. the enzyme targeted by sulfonamide can be modified to have and increased affinity for PABA B. Beta-lactamases are secreted to destroy the sulfonamide C. efflux pumps remove the sulfonamide from the cell D. protein channels modify their specificity, preventing sulfonamide from entering cells
A
Adenine and Thymine/Uracil for how many hydrogen bonds?
A - T forms two hydrogen bonds.
repressible operon
A bacterial operon that is usually on, but can be inhibited (repressed) when a specific molecule binds to a regulatory protein.
carcinogen
A cancer-causing substance
eukaryote
A cell that contains a nucleus and membrane bound organelles
alterations in the Cell Wall and Cytoplasmic Membrane
A cell's Competency is a result of what?
point mutation
A change in a gene at a single nucleotide pair.
methylation
A chemical modification of DNA that does not affect the nucleotide sequence of a gene but makes that gene less likely to be expressed. this marks DNA as self
mutagen
A chemical or physical agent that interacts with DNA and causes a mutation.
Typical Prokaryotic Chromosome
A circular molecule of DNA in the Nucleoid
What is a common nucleotide analog of thymine?
A common nucleotide analog of thymine is is 5'bromouracil.
lagging strand
A discontinuously synthesized DNA strand that elongates in a direction away from the replication fork. Has Okazaki fragments
What is the diameter of a eukaryotic chromatin fiber?
A eukaryotic chromatin fiber is about 30 nm in diameter.
What is the diameter of a eukaryotic nucleosome?
A eukaryotic nucleosome is 10 nanometers.
What is a frameshift insertion?
A frameshift insertion is the addition of one or a few nucleotide pairs that creates a new sequence of codons
What does a genome include?
A genome includes the entire genetic complement of an organism and its genes and nucleotide sequences that connect genes
What is a genome?
A genome is the entire genetic complement of an organism
How does a genome differ from a genotype
A genotype differs from a genome in that a genome also includes nucleotides that are not part of genes such as the nucleotide sequences that link genes together.
nutrients
Any chemical such as carbon, hydrogen, etc., required for the growth of microbial populations
base pairs
Any of the pairs formed between complimentary bases in the two nucleotide chains of DNA, such as A-T and C-G (DNA) A-U and C-G (RNA) A - T : forms two hydrogen bonds G - C : forms three hydrogen bonds
How is archael and eukaryotic DNA different from bacterial DNA?
Archael and eukaryotic DNA contains histones while bacterial DNA does not
Double Helix
Arrangement of DNA molecule; 2 Nucleotide chains arranged like a spiral ladder; Phosphate groups bonded to Deoxyribose molecules making up the sides of the ladder,and Nitrogen Bases,held together by H bonds, the rungs
room temperature
At what temperature can liquids treated with Ultrahigh-temperature sterilization be stored?
How does polymyxin work? Why is this method usually only used on the skin?
Attaches to phospholipids in the cytoplasmic membrane. This method of action also interferes with human cell membranes, where outer layers of cells are already dead
Having only one otganism present.
Axenic
Agents that kill bacteria are said to be A. inhibitory B. bacteriocidal C. bacteriostatic D. all of the above
B
If a bacterium acquired an antibiotic resistance gene via conjugation, the DNA would most likely originate from A. a bacteriophage B. an R-plasmid C. a sensitive bacterial cell D. a fragment of DNA in the environment
B
The action of some bacteriolytic chemical agents can be observed by noting a(n) A. increase in the turbidity of the medium B. decrease in the turbidity of the medium C. change in the color of the medium D. change in the surface tension of the medium
B
The antimicrobial effectiveness of which of the following is limited to exposed surfaces? A. microwaves B. UV rays C. x-rays/gamma rays D. eletrons
B
The complete elimination of all microorganisms, including viruses, is called A. disinfection B. sterilization C. decontamination D. any of the above, depending on the circumstances
B
The polyoxins interfere with A. cell membrane structure B. chitin biosynth C. fungal mitosis D. all of the above
B
The type of filter used when a syringe, pump, or vacuum is used to force the liquid through the filtration apparatus into a sterile collection vessel is called A. depth filter B. membrane filter C. nucleation track filter D. microblast filter
B
UV radiation is antimicrobial because A. the radiation generates significant amounts of heat within the given cell B. the energy present causes modifications or breaks in the DNA molecules C. the radiation generates magnetic poles that denature the cellular components D. all of the above
B
Which of the following statements about efflux pumps is true? A. they work by bringing in molecules they normally synthesize from their environment to allow the affected mechanism to continue B. the great number of efflux pumps a bacterial cell has, the more resistant to the antibiotic it will be C. they change the chem structure of the antibiotic D. they can never be modified to broaden the spectrum of antibiotics they work against
B
DNA ligase
A linking enzyme essential for DNA replication; catalyzes the covalent bonding of the 3' end of a new DNA fragment to the 5' end of a growing chain.
substitution
A mutation in which a nucleotide or a codon in DNA is replaced with a different nucleotide.
insertion
A mutation involving the addition of one or more nucleotide pairs to a gene.
silent mutation
A mutation that changes a single nucleotide, but does not change the amino acid created.
nonsense mutation
A mutation that changes an amino acid codon to one of the three stop codons, resulting in a shorter and usually nonfunctional protein.
What type of site (on an enzyme) does a noncompetetive inhibitor attach to and why?
A noncompetetive inhibitor attaches to an allosteric site to alter the active site so that it is no longer functional.
What is a nucleoside composed of?
A nucleoside is composed of a pentose sugar attached to one of five nitrogenous bases.
d
A nucleotide is composed of a. a five-carbon sugar b. phosphate c. a nitrogenous base d. all of the above
palindrome
A palindromic sequence is a nucleic acid sequence (DNA or RNA) that is the same whether read 5' (five-prime) to 3' (three prime) on one strand or 5' to 3' on the complementary strand with which it forms a double helix.
d
A plasmid is a. a molecule of RNA found in bacterial cells b. distinguished from a chromosome by being circular c. a structure in bacterial cells formed from plasma membrane d. extrachromosomal DNA
missense mutation
A point mutation in which a codon that specifies an amino acid is mutated into a codon that specifies a different amino acid.
The substitution of a nucleotide analog would result in what type of mutation?
A point mutation.
repressor
A protein that binds to an operator and physically blocks RNA polymerase from binding to a promoter site
b
A sequence of nucleotides formed during replication of the lagging DNA strand is a. a palindrome b. an Okazaki fragment c. a template strand d. an operon
insertion sequence
A simple transposon that contains genes only for those enzymes, such as the transposase, that are required for transposition
plasmid
A small, circular section of extra DNA that confers one or more traits to a bacterium
Transport media
A special type of medium used to move clinical specimens from one location to another while preserving the relative abundance of organisms and preventing contamination of the specimen or environment
promoter
A specific nucleotide sequence in DNA that binds RNA polymerase, positioning it to start transcribing RNA at the appropriate place.
codon
A specific sequence of three adjacent bases on a strand of DNA or RNA that provides genetic code information for a particular amino acid CODONS - Triplets of mRNA nucleotides that code for specific amino acids. For example, AAA is a codon for lysine. Ribosomes do NOT access genetic information from DNA. mRNA carries information to the ribosome in the form of codons. Codons UAA, UAG, and UGA instruct ribosomes to stop translating.
inducer
A specific small molecule that binds to a bacterial repressor protein and changes the repressor's shape so that it cannot bind to an operator, thus switching an operon on.
What is a substitution mutation?
A substitution mutation is mismatching of nucleotides or replacement of one base pair by another
conjugation
A temporary union of two organisms for the purpose of DNA transfer.
In self-dermination of transcription, what is the DNA sequence composed of?
A terminator sequence of DNA is composed of two symmetrical series: one very rich in guanine and cytosine bases, followed by a region rich in adenine bases.
prokaryote
A unicellular organism that lacks a nucleus and membrane bound organelles
What would the result be of thymine being replaced by a 5'bromouracil analog?
A wrong complement can form, the 5'bromouracil will pair with guanine rathe than adenine.
Which of the following molecules serves as the short-term recyclable energy supply for a cell? -triglycerides -ATP -glucose -phospholipids
ATP
What two molecules are produced by the light reactions and used to power the Calvin cycle? -ATP and NADPH -C6H12O6 and O2 -G3P and H2O -C6H12O6 and RuBP -CO2 and O2
ATP and NADPH
Which of the following processes does not take place in the cytoplasm of a bacterial cell? -The energy investment phase -glycolysis -citric acid cycle -ATP production by ATP synthase -acetyl CoA formation
ATP production by ATP synthase
Catabolic pathways, but not necessarily individual catabolic reactions, produce __________,or ___________, or both.
ATP;metabolites
pH
Acidic conditions enhance the antimicrobial effect of heat, some disinfectants are more efficient at low pH
Microorganism requiring acidic Ph.
Acidophile
Lactobacillus sp.
Acidophiles GRAM+RODS (NON-SPORE FORMING) used in food industry (produces lactic acid for flavoring, reducing pH); normal flora in humans
End products of fermentation, which are often useful to humans and aid in laboratory identification of microbes, includes what three things?
Acids,alcohols,gases
An organism that uses oxygen for a final electron acceptor.
Aerobe
microaerophiles
Aerobes that require Oxygen levels from 2-10% and have a limited ability to detoxify Hydrogen Peroxide and Superoxide Radicals
Aerobes use oxygen atoms as final electron acceptors in their electron transport chains in a process known as ____________ _______________.
Aerobic respiration
Using thioglycollate growth medium, how you would know an organism is aerotolerant aerobes?
Aerotolerant aerobes can grow equally well with or without oxygen; their growth is relatively evenly distributed throughout the medium
Why is agar a useful substance in the microbiology lab?
Agar does not solidify until it cools to about 40°C.
Have amplified DNA in tube. How do you visualize what you have?
Agarose Gel Electrophoresis.
separation of DNA molecules is through_
Agarose gel electrophoresis
humans, animals, and objects
Agents used for Microbial Control should control all microbial growth while being harmless to ______, ______, and _______.
mutagens
Agents, such as chemicals or radiation, that damage or alter genetic material (DNA) in cells.
Which of the following bacterial cell structures increases in size during binary fission? cell wall bacterial chromosome cell membrane cytoplasm. both the cell wall and cell membrane all of the above
All of the above
Precurser metabolites often produced in catabolic reactions are used to synthesize what?
All other organic compounds
genome
All the genetic information in an organism; all of an organism's chromosomes.
-the binding of a regulatory molecule to a protein at one site that affects the function of the protein at a different site.
Allosteric regulation
Facultative halophiles
Although microorganism does not require high salt concentrations, they can tolerate them
c
Although two cells are totally unrelated, one cell receives DNA from the other cell and incorporates this new DNA into its chromosome. This process is a. crossing over of DNA from the two cells b. vertical gene transfer c. horizontal gene transfer d. transposition
_________ is the transfer of the amine group from ammonia to form an amino acid.
Amination
_________ reactions are those that can proceed in either direction, thus are reversible.
Amphibolic
What types of reactions are metabolic reactions that are reversible? ( they can operate catabolically or anabolically.)
Amphibolic reactions
How many nucleotides does an Okazaki fragment contain?
An Okazaki fragment consists of 1000 to 2000 nucleotides.
duplication
An aberration in chromosome structure due to fusion with a fragment from a homologous chromosome, such that a portion of a chromosome is duplicated.
What is an auxotroph?
An auxotroph is a mutant organism that has different nutritional needs than it's wildtype counterpart.
What connects the two photosystems in the light reactions? -Chlorophyll -A thylakoid -An electron transport chain -The Calvin cycle -A chain of glucose molecules
An electron transport chain
Which of these is NOT true of an enzyme? -An enzyme is usually a protein. -The names of most enzymes end in "-ase." -An enzyme raises the activation energy of a reaction. -The active site is where the substrate attaches to the enzyme.
An enzyme raises the activation energy of a reaction.
RNA polymerase
An enzyme that adds and links complementary RNA nucleotides during transcription
helicase
An enzyme that untwists the double helix of DNA at the replication forks.
inducible operon
An operon that is normally off but can be activated and is normally catabolic
Chemoautotrophs
An organism that derives energy (CO2) from the oxidation of inorganic compounds, such as hydrogen sulfide (many archaebacteria)
Facultative anaerobes
An organism that makes ATP by aerobic respiration if oxygen is present but that switches to fermentation under anaerobic conditions.
Chemoheterotrophs
An organism that must consume organic molecules for both energy and carbon. (most bacteria, protozoans, fungi, animals)
Obligate Anaerobe
An organism that only carries out fermentation or anaerobic respiration. Such organisms cannot use oxygen and in fact may be poisoned by it.
genotype
An organism's genetic makeup
phenotype
An organism's physical appearance, or visible traits.
An organism that cannot tolerate oxygen.
Anaerobe
mRNA, tRNA, and rRNA
Another RNA Polymerase transcribes ____, ____, ___ ____.
Methionine
Another way in which Eukaryotic Translation differs from Prokaryotic Translation- the First Amino Acid is ____________, instead of being N-formylmethionine
_____________ bacteria derive electrons from inorganic compounds such as H2S, producing waste such as sulfer.
Anoxygenic
an antibiotic, including penicillin, that contains the four-membered heterocyclic B-lactam ring
B-lactam antibiotic
what is the biggest group of bacteria depending on their carbon and energy sources? what is a big group? what are the small and odd?
BIGGER GROUP: Photoautrotrophs BIG GROUP: Chemoheterotrophs Small and odd: photoheterotrophs/ chemoautotrophs
What organism is used to quality control the autoclave and why?
Bacillus stearothermophilus it grows at 56 degrees C and forms spores, thermophile. If it is not killed by the autoclave, it did not reach the necessary conditions for sterilization
Why is binary fission more quick and efficient when compared to eukaryotic cell division?
Bacteria do not need to form a mitotic spindle nor dissolve a nuclear membrane.
bacteria conjugation
Bacteria use Pili to swap plasmid DNA. This can be used to share a gene for antibiotic resistance.
What are bacteriocin plasmids?
Bacteriocin plasmids carry genes for proteinacious toxins called bacteriocins which kill bacterial cells of the same or similar species that LACK THE PLASMID.
How are bactericidal, bacteriostatic, and bacterial lytic different?
Bacteriostatic: inhibit bacterial growth Bacteriocidal: kills bacteria Bacteriolytic: lyses bacteria
How does base excision repair work?
Base-excision- DNA polymerase I comes in a removes mutated base pairs then seals gap back together with new from DNA polymerase I
Insertions
Bases added to DNA
Deletions
Bases lost from DNA
Why is the lagging strand lagging?
Because DNA polymerase III adds nucleotides only to the 3' end of the new strand, the enzymes move away from the replication fork as it synthesizes a lagging strand.
Why is it useful to plot bacterial growth on a logarithmic graph?
Because the number of cells increases rapidly, a logarithmic graph allows you to visualize the complete growth curve.
d
Before mutations can affect a population permanently, they must be, a. lasting b. inheritable c. beneficial d. all of the above
Halogens
Believed that they damage Enzymes via Oxidation or by Denaturing them
- is a process in which enzymes split pairs of hydrogenated carbon atoms from fatty acid and join them coenzyme A to form acetyl-CoA.
Beta-oxidation
Most bacteria divide by which method?
Binary fission
Which of the following statements is true for binary fission? Binary fission results in the production of two genetically identical daughter cells. Binary fission results in the production of one genetically identical daughter cell. Binary fission occurs as quickly as eukaryotic mitosis. Replicated chromosomes are separated by attaching to a mitotic spindle. Daughter cells must mature before they are able to perform binary fission.
Binary fission results in the production of two genetically identical daughter cells.
How does penicillin work?
Blocks the formation of peptide cross links in the PG cell wall
increases
Boiling temperature __________ as pressure increases.
Both types of diabetes result in_
Both result in elevated blood glucose levels = hyperglycemia.
What is the difference between a broad spectrum and narrow spectrum antibiotic?
Broad: kills both G+ and G- bacteria Narrow: kills either G+ or G- bacteria
A liquid nutrient -rich medium used for cultivating microorganisms.
Broth
How Antimicrobial Agents kill microbes
By altering their cell walls or cytoplasmic membranes; or by interfering with their metabolism and reproduction by damaging proteins and nucleic acids
How you identify the oxygen requirements of organisms?
By using a liquid thioglycollate growth medium
how can scientists create gene libraries?
By using restriction enzymes, which generate fragments of the DNA of interest, and then using ligase to synthesizing recombinant vectors
All antibiotic-resistant pathogens A. will be killed by the antibiotic B. will have mutations in their DNA C. will not be killed/inhibited by antibiotic D. obtained their resistance from a bacteriophage E. have R plasmids
C
How do beta lactamases help to overcome antibiotics with beta-lactam rings? A. they pump the antibiotics out of the cell B. they modify the enzymes that these antibiotics act upon C. they actively destroy the chemical structure of the antibiotic D. they prevent the antibiotic from entering the cell
C
How might a mutation result in antibiotic resistance? A. it facilitates R-plasmid transfer during bacterial conjugation B. mutations could allow DNA fragments to be taken up by cells C. mutations can result in a modification of an enzyme that could interfere with the action of the antibiotic D. mutations allow for bacteriophages to spread DNA to other bacteria
C
Streptomyces is a A. mold B. penicillin C. actinomycete
C
The most successful agents used for antiviral chemotherapy are A. protein synth inhibitors B. ATP reductase inhibitors C. nucleoside analogs D. nucleotide analogs
C
The type of filter most often used for liquid sterilization in the microbiology lab is A. depth filter B. nucleation track filter C. membrane filter D. microbistat filter
C
The vegetative cells of Mycobacterium tuberculosis are resistant to many germicides because of A. an extra membranous layer between the cell wall and the plasma membrane B. the complex nature of the plasma membrane itself C. the waxy nature of the cell wall D. the lattice work found in the glycocalyx
C
Which is a unique macromolecule present in certain viruses that is a target for antiviral agents? A. ribosomes B. DNA C. reverse transcriptase D. RNA
C
Which of the following chemotherapeutic agents would prevent the formation of THF in a bacterial cell? A. chlorampehnicol B. fluoroquinolone C. sulfonamide D. penicillin
C
___ are applied to living tissues; ___ are used on inanimate objects A. disinfectants/sterilants B. antiseptics/sterilants C. antiseptics/disinfectants D. disinfectants/antiseptics
C
What is the correct general equation for cellular respiration? -C6H12O6 + 6 CO2 → 6 O2 + 6 H2O + ATP energy -6 O2 + 6 H2O + ATP energy → C6H12O6 + 6 CO2 -C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + ATP energy -6 CO2 + 6 H2O + ATP energy → C6H12O6 + 6 O2 -C6H12O6 + 6 H2O → 6 CO2 + 6 O2 + ATP energy
C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + ATP energy Cellular respiration extracts energy from glucose (C6H12O6) to produce smaller energy packets (ATP).
In the light independent pathway of photosynthesis, carbon fixation occurs in the Calvin-Benson cycle , in which __________ is reduced to produce glucose.
CO2
Which of the following is LEAST likely to be catabolized by microorganisms? -lipids -starch -CO2 -proteins
CO2
Which of these is NOT a product of photosynthesis in bacteria? -glyceraldehyde-3-phosphate -O2 -CO2 -glucose
CO2
CODONS
CODONS - Triplets of mRNA nucleotides that code for specific amino acids. For example, AAA is a codon for lysine. Ribosomes do NOT access genetic information from DNA. mRNA carries information to the ribosome in the form of codons. **Codons UAA, UAG, and UGA instruct ribosomes to stop translating.
What produces glyceraldehyde-3-phosphate by fixation of CO2 molecules.
Calvin-Benson cycle
How PCR can be automated?
Can be automated using a thermocycler, a device that atomically performs PCR by continuous cycling all the necessary reagents through 3 temperature regimens
Gaseous Agents
Can be hazardous to people, often highly explosive, extremely poisonous, and are potentially Carcinogenic
Treponemapallidum
Can turn into syphilis, gram - spirhochaete
__________ ________ _______can be used to distinguish those bacteria that can ferment the carbohydrate from those that cannot.
Carbohydrate fermentation tubes
1' through 5'
Carbon atoms in Deoxyribose are numbered __ _______ __
What provides the carbon atoms that are incorporated into sugar molecules in the Calvin cycle? -G3P (C3H6O3) -RuBP -Carbon dioxide (CO2) -Glucose (C6H12O6) -Sucrose (C12H22O11)
Carbon dioxide (CO2)
Plant pigment that acts as an antioxidant.
Carotenoid
_____________ pigments protect many phototrophic organisms from photochemically produced singlet oxygen.
Carotenoid
What is the function of mRNA?
Carries genetic information from a chromosome to ribosomes as triplets of RNA nucleotides (codons) that encode AA sequences.
heterotrophs
Catabolize reduced organic molecules (proteins, amino acids, carbohydrates, and fatty acids) they acquire from other organisms
How restriction enzymes are categorized?
Categorized in two groups based on type of cut -Cuts with sticky ends -Cuts with blunt ends
Neisseria gonorrheae
Causes gonorrhea, an STD (Proteobacteria), pili, fastidious
To a ribosome, DNA is like a foreign language written in a foreign alphabet. The cell does the following to help
Cell "transcribes" the "foreign alphabet" of DNA nucleotides (genes) into a "familiar alphabet" of RNA nucleotides. Cell "translates" the "familiar alphabet letters" (RNA nucleotides) of the familiar alphabet into "words" (amino acids) Those "words" (amino acids) then make up the "message" of polypeptides.
To a ribosome, DNA is like a foreign language written in a foreign alphabet. The cell does the following to help
Cell transcribes the "foreign alphabet" of DNA nucleotides (genes) into a "familiar alphabet" of RNA nucleotides. Cell translates the "familiar alphabet letters" (RNA nucleotides) of the familiar alphabet into "words" (amino acids) Those "words" (amino acids) then make up the "message" of polypeptides.
What is wrong with a person that has Type II diabetes?
Cells do not respond appropriately to insulin.
Hypertonic
Cells in a __________ solution of salt or sugar lose water; cell desiccates
high osmotic pressure
Cells in a hypertonic solution of salt or sugar lose water and the cell desiccates, the removal of water inhibits cellular metabolism because enzyes are fully functional only in an aqueous environment.
d
Cells that have the ability to take up DNA from their environment are said to be a. Hfr cells b. transposing c. genomic d. competent
Which of the following statements are incorrect in regards to the metabolic processes? -Cells typically reproduce once they have tripled in size. -Every cell acquires nutrients , which are the chemicals necessary for metabolism. -Energy is stored in the chemical bonds of ATP.
Cells typically reproduce once they have doubled (not tripled) in size.
Competent
Cells with the ability to take up DNA are said to be ____________
Is cheese basic or acid?
Cheese is acidic.
Bacteriostatic, Fungistatic, Virustatic
Chemical or Physical Agents that inhibit metabolism and growth of Bacteria, Fungi, and Viruses respectively, but do not necessarily kill or inactivate them
In ______________, ions flow down their electrochemical gradient across a membrane through ATP synthase (ATPase) to synthesize ATp.
Chemiosmosis
Oxidative phosphorylation and photophosphorylation use what type of osmosis?
Chemiosmosis
__________ remove wastes and add nutrients so that bacteria may remain in the log phase indefinitely.
Chemostats
Photosynthesis is a process in which light enulergy is captured by pigment molecules called _____________ (bacteriochlorophylls in some bacteria) and transferred to ATP and _____________.
Chlorophylls;metabolites
In which of the following organelles does photosynthesis take place? -Ribosome -Central vacuole -Mitochondrion -Nucleus -Chloroplast
Chloroplast -Chloroplasts use energy from light to transform carbon dioxide and water into sugar and oxygen.
What are chromatin fibers?
Chromatin fibers are clumps of nucleosomes.
What is the function of chromatin fibers?
Chromatin fibers fold and are organized into active euchromatin and inactive heterochromatin.
Why does it take more radiation to kill Clostridium than Saccharomyces?
Clos. has spores.
acetone and alcohol are produced by ___________ during fermentation.
Clostridium
incubation
Colonies develop from each isolate
Visible population of microorganisms living in one place;an aggragation of cells arising from one single parent cell.
Colony
_________ is a generic term meaning "a discrete mass of one type of bacterial cell";
Colony
A single cell or group of related cells that produce a colony.
Colony-forming unit (cfu)
What is the cause for a cell being competent?
Competence results from alterations in the cell wall that allows DNA to enter the cell wall.
What are "competent" cells?
Competent cells are cells that take up DNA from their environment.
Aldehydes
Compounds containing terminal -CHO groups
What is conjugation?
Conjugation is a a process by which some bacterial cells transfer DNA to other bacterial cells.
Prokaryotic Genomes
Consists of a circular molecule of DNA localized in a region of the cytoplasm called the nucleoid, haploid, no histones, there usually are one or more plasmids found in prokaryotes over 500 types.
Aldehydes
Cross-link with Amino, Hydroxyl, Sulfhydryl, and Carboxyl groups to denature Proteins and inactivate Nucleic Acids
In __________ ____________, the electrons return to the original reaction center after passing down the electron transport chain.
Cyclic photophosphorylation
Antibiotic resistance due to horizontal gene transfer could involve which of the following? A. the uptake of DNA from its surroundings B. transfer of R plasmid via bacterial conjugation C. DNA mutation making an altered enzyme that can degrade the antibiotic D. A and B E. A and C
D
Antimicrobial drugs are classified on the basis of A. molecular structure B. mechanism of action C. spectrum of antimicrobial activity D. all of the above
D
Antimicrobial drugs are often grouped according to A. molecular structure B. spectrum of antimicrobial activity C. mechanism of action D. all of the above
D
Important targets of antibiotics in Bacteria are A. the cell wall B. the cytoplasmic membrane C. DNA replication and transcription elements D. all of the above
D
Tetracycline resistance is likely due to which mechanism? A. efflux pumps B. beta lactamases C. modification of an enzyme D. modification of a porin E. importing of a molecule outside of the cell to allow a metabolic pathway to continue
D
The beta-lactam antibiotics (like penicillin) A. inhibit plasma membrane synth B. inhibit protein synth C. prevent chromosomal replication D. inhibit cell wall synth
D
The modification of existing cell structures could result in the resistance to which antibiotics? A. tetracycline B. sulfonamide C. penicillin D. A and B E. all of the above
D
Which chemotherapeutic agent blocks the formation of peptide cross links in bacterial cell walls? A. rifampin B. sulfonamide C. tetracycline D. penicillin
D
Which is not a reason why microorganisms may have an inherent resistance to an antibiotic? A. the org may be impermeable to the antibiotic B. the org may be able to pump out an antibiotic entering the cell C. the org may be able to alter the antibiotic to an inactive form D. the org may be protected from the drug by its nuclear membrane
D
Which of the following are classified as electromagnetic radiation? A. microwaves B. UV rays C. x-rays/gamma rays D. all of the above
D
Which of the following is a chemical agent that is used to inhibit microbial growth inside the human body? A. disinfectant B. sanitizer C. antiseptic D. chemotherapeutic agent
D
Which of the following is true about antibiotic resistance? A. almost all pathogenic microbes have acquired resistance to some chemotherapeutic agents B. resistance can be minimized by using antibiotics correctly and only when needed C. resistance to a certain antibiotic can be lost if antibiotic is not used for several years D. all of the above
D
Which statement is true about heat sterilization? A. microbial death is more rapid at acidic pH B. high concentrations of sugars and salts influence sterilization time C. the amount of water in a substance is a major factor in heat resistance D. all of the above
D