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Microbiology 1220 Mid Term 1
Flashcards for Microbiology (MBIO 1220) Distance Education for the the University of Manitoba
236
Microbiology
Undergraduate 1
10/05/2012

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Term
Define Spontaneous Generation
Definition
The theory that organisms arise spontaneously from non-living material
Term
What is the scientific contribution of Hooke?
Definition
Hooke saw microobes in 1665
Term
What is the scientific contribution of Leeuwenhoek?
Definition
Leeuwekhoek saw bread mould in 1674
Term
What is the scientific contribution of Pasteur?
Definition
Pasteur disproved spontaneous generation in 1861
Term
What is the scientific contribution of Tyndall?
Definition
Tyndall discovered endospores in the 1860's.
Term
What is the scientific contribution of Jenner?
Definition
Developed smallpox vaccine in 1796
Term
What is the scientific contribution of Koch?
Definition
Developed protocols for handling bacteria in lab, established rules to be used to determine causative agent of disease (Koch’s Postulates) in the 1800s
Term
What is the scientific contribution of Ehrlich?
Definition
Started chemotherapy to treat diseases in the 1900s
Term
What is the scientific contribution of Fleming?
Definition
Discovered Penicillin in the 1900s
Term
How do the three Domains differ in size?
Definition
Bacteria (0.3-2µm) Archaea (0.3-2µm) Eucarya (5-50µm)
Term
Which domains have nuclear membranes?
Definition
Eucarya
Term
Which domains have peptides in the cell wall?
Definition
Bacteria
Term
Which domains have membranous organelles?
Definition
Eucarya
Term
Which domains are prokaryotes?
Definition
Archaea
Term
Define Prokaryote
Definition
Single celled organism with no membrane bound nucleus or lipid bound organelles with DNA in a nucleoid
Term
List the organization of biological hierarchy, from greatest to least specificity
Definition
DKPCOFGS (Don’t Kick Police Cars, Otherwise Fools Get Shot) - Domain Kingdom Phylum Chordata Order Family Genus Species
Term
Define Algae
Definition
Diverse single and multi celled organisms that have chloroplasts, undergo photosynthesis, have flagella and are found primarily in water
Term
Define Fungi
Definition
Single and multi celled organisms that gain energy from degrading organic material and are found primarily on land
Term
Define Protozoa
Definition
Single celled organisms with un-rigif cell walls that are found on both land and water and require organic compounds as food which they ingest as particles.
Term
Define virus
Definition
Nucelic acid with a protein coat, that can only multiply inside a host and is therefore an obligate intracellular parasite
Term
Define viroid
Definition
An organism that consist of short RNA segment without a protein coat that can only multiply inside a host
Term
Define prion
Definition
An organism consisting of protein without nucelic acid
Term
Define Helminth
Definition
A parasite such as round and tape worms
Term
How do viruses, prokaryotes and eukaryotes differ in size?
Definition
Viruses (10nm-100nm) Prokaryotes (100nm-1000nm) Eukaryotes (10m-10mm)
Term
What 6 elements make up 99.5% of living material by weight?
Definition
CHONPS
Term
Define Molecule
Definition
2 or more atoms with a chemical bond
Term
Define Compound
Definition
2 or more different elements bonded together
Term
How are ionic bonds created?
Definition
Two or more elements trade electrons, join as ions
Term
How do ionic bonds fare in water?
Definition
Break at room temperature, 100x weaker than covalent
Term
What defines an organic compound?
Definition
Covalent bonds with C and H
Term
How do Polar and Non-polar covalent bonds differ?
Definition
Polar have slight pos. and neg. charges (OH/NH/OC/NC) versus no charges (CC/CH/HH)
Term
How are Hydrogen bonds formed? How strong are they?
Definition
H+ attracted to negatively charged atom. Weak, constaltly breaking and forming at room temperature
Term
Why is water considered a universal solvent?
Definition
Dissolves polar compounds - splits them into ions (polar sides attract - ion, etc)
Term
What is the concentration of OH and H ions in solutions that are Basic, Acidic, and Neutral?
Definition
Basic (10[OH-], 10^14[H+]), Acidic (10^7[OH-], 10^7[H+]) , Neutral (10^14[OH-], 10^0[H+])
Term
What is the function of proteins?
Definition
Catalyze enzyme reactions, determine structure/shape of ribosomes, take nutrients in/out of cell
Term
What is the general structure of an amino acid, and how many are there?
Definition
Amino + side chain + carboxyl. 20 different ones that differ by side chain
Term
How do hydrophobic and philic proteins differ?
Definition
Phobic - nonpolar, many CH3 groups. Philic - polar, few CH3 groups
Term
What is the function of carbohydrates?
Definition
Food, building block of DNA
Term
What is the ratio of CHO in carbohydrates?
Definition
1:2:1
Term
What are the two types of monosaccharides and how do they differ?
Definition
5-carbon (Deoxy/ribose), 6-carbon (gluocose, galactose, fructose)
Term
What are 2 examples of disaccarides?
Definition
Lactose, sucrose
Term
What are 2 examples of polysaccarides?
Definition
Cellulose, glycogen
Term
Define Oligosaccarides
Definition
Polymer containing 3-6 monosaccarides
Term
What is the structure of DNA
Definition
N-ring base (purine) with deoxy base and a phosphate backbone, wound around histones
Term
What is the structure of RNA
Definition
Single stranded DNA with ribose base and U instead of T
Term
Are lipids hydrophilic or hydrophobic?
Definition
Hydrophobic, non-polar
Term
How do simple lipids differ from carbohydrates?
Definition
Different ratio of CHO
Term
What are Fats composed of?
Definition
Fatty acids and glycerol
Term
How can you determmine if a fat is a mono/di/triglyceride?
Definition
Count the number of fatty acid chains
Term
In what case is a simple lipid unsaturated?
Definition
Double bond s are present in a fatty acid chain (liquid at room temperature)
Term
What is the structure of compound lipids?
Definition
Fatty acids + glycerol + other
Term
What is the structure of Phospolipids?
Definition
Phosphate + fatty acid + glycerol
Term
What is the maximum magnification of a light microscope?
Definition
1000x
Term
How does light go from the lamp to eyes in a light microscope?
Definition
Specimen, magnifying lens
Term
What Domains are viewable under a light microscope?
Definition
Eucarya and Bacteria - good for up to 10µm
Term
What is the maximum magnification of an electron microscope?
Definition
100,000x(+)
Term
What acellular organisms are viewable under an electron microscope?
Definition
Viruses
Term
What are the TEM and SEM used for viewing in a cell?
Definition
TEM (internal cellular structures), SEM (surface structures)
Term
What is the purpose of an atomic force microscope?
Definition
View objects at the atomic level
Term
How are magnification and resolution different? Which would provide better resolution - an electron or light microscope?
Definition
Magnification is image enlargement, Resolution is the degree to which fine detail can be distinguished.

Light microscope will provide better resolution.
Term
How does a simple stain work?
Definition
Basic dye for color, negatively charged nucleic acids and proteins are stained with a positively charged dye
Term
What is a differential stain used for?
Definition
Distinguishing between bacterial groups
Term
What function does a gram stain serve?
Definition
Determine if a cell is gram + or -, which reflect differences in cell wall structure.
1st stain - Purple
2nd stain - Pink
Term
What genus would you be trying to detect by using an acid-fast stain?
Definition
Mycobacterium
Term
Why is a capsule stain used?
Definition
Capsules don’t take up certain stains, this used to make capsules stand out against background
Term
Why is an endospore stain used?
Definition
Stains endospores, which do not stain easily
Term
Why is a flagella stain used?
Definition
Coats thin flagella, visible under light microscope
Term
What are the steps in a Gram stain?
Definition
Flood smear with primary stain, rince, flood with dilute iodine, rince, add 95% alcohol to decolor gram negative, counterstain added to stain gram negative
Term
What are the 4 bacterial shapes?
Definition
Cocci (spherical), Bactillus (columnar), Spiral, Pleomorphic (varying in shape)
Term
What is the function of the cytoplasmic membrane?
Definition
Selectively permeable barrier made of phospholipids with embedded sterols and hopanoids.
Term
What is the fluid mosaic model?
Definition
Proteins are not static, dynamic nature means the cytoplasmic membrane is constantly changing and fluid
Term
What is the structure of peptidoglycan?
Definition
AA/sugar mesh with covalent bonds, alternating NAG/NAM sugar units cross linked to AA's
Term
Peptidoglycan, found only in the cell walls, is the target of...
Definition
Antibiotics and Lysosome (a product of the body)
Term
What is the structure and function of the membrane outsode of the peptidoglycan layer in Gram Negative bacteria?
Definition
Consists of LPS (endotoxin), phospholipids and proteins, plays a role in fever/inflammation
Term
How do capsule and slime layers differ? What is their function?
Definition
Gel like layers that function as protection/attachment. Capsule layer (distinct/gelatinous) Slime Layer (diffuse/irregular)
Function in adhereing to surfaces are thwarting innate defense system
Term
What is the function of flagella?
Definition
Protein structure responsible for mobility, spin in propellar like fashion
Term
What is Chemotaxis?
Definition
Phenomenon where bacteria sense and move according to chemical attractants (cells move towards) or repellants (cells move away)
Term
What is the function of pili and how do they differ from flagella?
Definition
Attachment to surfaces/bacterial mating. Shorter/thinner than flagella and can't been seen under light microscope
Term
What is a plasmid?
Definition
Circular, supercoiled double stranded DNA that the cell does not actually need, but may provide an advantage (can encode enzymes that destroy antibiotics)
Term
How are bacterial ribosomes different from eukaryotic ones? Why is this useful?
Definition
Size/composition. Exploited for drug design
Term
What are storage granules?
Definition
Polymers of nutrients stored until required
Term
How are glucose, carbon and phosphate stored as granules?
Definition
Glycose (glycogen), Carbon (Poly-B-hydroxlbutrate), Phosphate (Volutin granules)
Term
What is an endospore and why is it advantageous?
Definition
A resistant form of life some bacteria (particularily Bactiuus/Clostridium) can differentiate to, advantageous as it allows cells to lie dormant until conditions improve
Term
Describe a spore
Definition
DNA surrounded by many levels of cytoplasmic membtrane/peptidoglycan. Can't reproduce or grow, will revert when conditions improve
Term
Define microtubles
Definition
Long hollow cylinder form mitotic spindle, make up cilia and flagella framework along which organelles move
Term
Define actin filaments
Definition
Enable cytoplasm to move
Term
Describe intermediate filaments
Definition
Function like ropes, strengthening cell mechanically, enable cell to resist physical stresses
Term
How are flagella different/simmilar?
Definition
Protein appendages that appear to project out but are covered by cytoplasmic membrane extension, flagella give mobility, cilia help move material away/towards cell
Term
Describe the structure of the nuclear envelope
Definition
Two lipid bilayer membranes, protein strucures (nuclear pores)
Term
Where is mRNA synthesized?
Definition
Nucleolous
Term
Describe the structure of the mitochondria membrane
Definition
Two lipid bilayer membranes (inner/outer), inner highly folded (cristae) to increase surface area, enclosed by inner is the matrix
Term
What is the stroma in chloroplasts analgous to in mitochondria?
Definition
The matrix (inner space)
Term
Define generation/doubling time
Definition
The time for a population to double in number (generally bacteria)
Term
What do the variables in the function: Nt = N0 x 2n represent
Definition
N0 - original number of cells, Nt - number of cells at given time t, n - number of divisins during time t
Term
Define sterile
Definition
free of microbes
Term
Define Aseptic techniques
Definition
procedures that minimize chance of organisms being introduced
Term
What is agar used for?
Definition
Solidifying a liquid culture medium
Term
Describe the streak-plate method
Definition
Sterilized loop dipped in bacteria, and drawn across a plate three times at different angles to dilute the concentration of cells
Term
What is a stock culture?
Definition
A culture stored for later use
Term
Define a closed/batch culture
Definition
A culture in which nutrientsare not renewed and wastes are not removed
Term
Define an open/continuous culture
Definition
A culture in which nutrients are added and wastes removed regularily
Term
What are the phases in bacterial growth in a culture?
Definition
Lag, exponential (log), stationary, death, prolonged death (LESDP)
Term
Describe the lag phase
Definition
Bacterial culture diluted/transferred, cells not rapidly increasing for the moment (synthesizing macromolecules)
Term
Describe the exponential (log) phase
Definition
Cells divide at a constant rate, generation time measured, primary and secondary metabolites synthesized in early/late log phase. Endospores form in late log phase if possible
Term
Describe the stationary phase
Definition
No more energy or nutrients, number of cells constant because some die and release contents and are cannabalized
Term
Describe the death phase
Definition
Decrease in number of viable cells, exponential but slower than growth
Term
Described the prolonged death phase
Definition
99% dead, days to years, cannibalizing continues, survival of the fittest
Term
Define optimum growth temperature
Definition
Temperature at which growth is fastest
Term
Define psychrophiles
Definition
OGT 15-30
Term
Define psychtrophs
Definition
OGT 20-30, cause food spoilage
Term
Define mesophiles
Definition
OGT 35-40, found in human body - most common pathogens
Term
Define thermophiles
Definition
OGT 45-70, hot springs/compost/water heaters
Term
Define hyperthermopiles
Definition
OGT 70+, archeae
Term
Define obligate aerobes
Definition
Absolute oxygen requirements
Term
Define obligate anaerobes
Definition
Capable of growth in the absence of oxygen
Term
Define facultative anaerobes
Definition
Growth better with oxygen
Term
Define microaerophiles
Definition
Small oxygen requirements, more inhibitory
Term
Define aerotolerant anaerobes
Definition
Oxygen indifferent
Term
Why do all cells attempt tp maintain a cytoplasmic pH near 7?
Definition
Preserve enzyme function
Term
Define neutrophiles
Definition
Prefer pH near 7
Term
Define acidophiles
Definition
Prefer pH 5.5 or lower
Term
Define alkalophiles
Definition
Prefer pH 8.5 or higher (exchange internal Na ions for internal protons)
Term
Define plasmolysis
Definition
Solute concentration higher out of cell - cell dehydrates
Term
Define halotolerant
Definition
Tolerate high salt concentrations
Term
Define halophiles
Definition
Require high salt concentrations
Term
What is the function of the cell wall in maintaining water homeostasis?
Definition
Enables bacteria to survive hypotonic enviornment while preventing osomtic lysis
Term
How do cells prevent plasmolysis
Definition
Increase internal solute concentration
Term
Define heterotroph
Definition
Use organic C
Term
Define autotroph
Definition
Use inorganic C (CO2)
Term
Define phototroph
Definition
Use energy from sun
Term
Define chemotroph
Definition
Use energy from oxidizing chemical compounds
Term
Define complex media
Definition
Contains variety of ingredients
Term
Define defined media
Definition
Contains precise amounts of pure chemicals
Term
Define differential media
Definition
Contains substances that bacteria change in a recognizable way
Term
Define direct cell count
Definition
Includes total number of cells (living and dead)
Term
Define viable cell count
Definition
Includes viable cells, 24 hour incubation required
Term
Describe the process of doing a plate count
Definition
Sample diluted in 10 fold increments, 0.1-1mL transferred to sterile petri dish, mixed with agar, when agar hardens - plate incubated and colonies farm (multiple layers)
Term
Describe the process of doing a spread plate
Definition
Plate count where 0.1-0.2 mL dilution spread on hard agar plate with sterile glass rod, after incubation colonies form on surface (1 layer)
Term
Define Sterilization
Definition
Process of destroying all micro-organisms/viruses through physical/chemical means
Term
Define Disinfection
Definition
Process that eliminates most/all pathogens in the material
Term
Define Antiseptics
Definition
Disinfectant non-toxic enough to be used on skin
Term
Define Sanitization
Definition
Process that substantially reduces microbe population to meet health standards
Term
Does Pasteurization sterilize?
Definition
No, pasteurization reduces the number of organisms
Term
What is the HTST form of Pasteurization?
Definition
High temperature, low time - 72 degrees for 15 seconds
Term
What is the UHT form of Pasteurization?
Definition
Ultra high temperature (sterilizes) 140 degreece for 12 seconds
Term
What does an autoclave do?
Definition
Sanitizes and kills endospores - pressurized steam at 121 degrees at 15 psi for 15 minutes
Term
How does canning work, and what is the process for home and commercial canning?
Definition
Moist heat/Anaerobic Chamber. Home (115 @15 min) Commercial (121 @ 2.5 min)
Term
What do drying ovens do? Give an example of something sterilized by drying ovens
Definition
Oxidize cell components, denatures proteins, high temp/time required versus moist heat. Lab glassware (160@2-3 hours)
Term
Give some examples of physical methods of destroying organisms
Definition
Steriliants, high/intermediate/low level disinfectants
Term
Define steriliants and provide an example item that would require their use
Definition
Destroy all microbes (including endospores and viruses), 6-10 hours, used on scalpels
Term
Define High Level Disinfectants and provide an example item that would require their use
Definition
All viruses and vegetative organisms (not endospores), sterilants used for 30 minutes. Used on gastrointestinal endoscopes.
Term
Define Intermediate Level Disinfectants and provide an example item that would require their use
Definition
Destroy vegetative bacteria, most viruses (not endospores). Used on stethoscopes
Term
Define Low Level Disinfectants and provide an example item that would require their use
Definition
Destroys fungi, vegetative bacteria, enveloped viruses
Term
What are some considerations to take into account when selecting a disinfectant?
Definition
toxicity, activity in presence of organic matter, compatibility, residue, enviornmental risk, cost/availbility, storage/stability
Term
How do Alcohols work? What are they effective against, and provide an example
Definition
Damage membrane lipids. Effective Against: VB/F (~E/V). Example: Ethanol/Isopropanol Alcohol
Term
How do Aldehydes work? What are they effective against, and provide an example
Definition
Sterilants, inactivate proteins/nuc acids. Effective Against: M/V. Example: 2% Glutaradehyde
Term
How do Biguanides work? What are they effective against, and provide an example
Definition
Disruput cell membranes. Effective Against: VB/F, some V. Example: Chlorohexadine
Term
How do Volatile Chemicals work? What are they effective against, and provide an example
Definition
Gas sterilants for large items, damage proteins. Effective Against: M/V. Example: Ethylene Oxide
Term
How do Halogens work? What are they effective against, and provide an example
Definition
Disinfectant, oxidize proteins/cellular components. Effective Against: M/V. Example: Cl, Bleach, Iodine
Term
How do Metal Compounds work? What are they effective against, and provide an example
Definition
Affect protein function, toxic to humans in effective concentrations. Effective Against: M/V. Example: Silver Nitrate, Mercury, Zinc
Term
How do Oxidizing Agents work? What are they effective against, and provide an example
Definition
Oxidize cell components. Effective Against: Anaerobic Organisms. Example: Ozone, Hydrogen Peroxide
Term
How do Phenals work? What are they effective against, and provide an example
Definition
Destroy Cytoplasmic Membrane, denature proteins, disinfectant. Effective Against: Most VB. Example: Lysol, mouthwash, cleaning up blood on hospital floor
Term
How do QUATS work? What are they effective against, and provide an example
Definition
Detergent, destroy Cytoplasmic Membrane and denature proteins. Effective Against: VB, some V. Example: Detergents
Term
Name some methods of preserving perishable products
Definition
Low temperature (enzyme reactions slowed), addition of salt/sugar (dehydrate cells), dessication (remove water), lycophilization (freeze dry)
Term
How does anabolic metabolism work? What does it require?
Definition
Builds larger molecules from smaller ones (biosynthesis). Requires: energy source, B12, biotin, folic acid, Vitamin E
Term
What is anabolic metabolism required for?
Definition
Replicating working molecules in cell, growth/division, secretion of cell products
Term
Explain how anabolic/catabolic pathways and ATP/ADP fit together to form a cycle
Definition
ADP is filled up with energy by enzymes in catabolic pathways to form ATP which is then broken down in anabolic pathways to form ADP
Term
What are the products and reactants of glycolysis? What is required for glycolysis?
Definition
Reactants: glucose
Product: Pyruvic Acid. Enzyme niacin required
Term
Bacterial break down pyruvic acid to _____ and _____
Definition
Carbon dioxide and water
Term
During fermentation, how many molecules (approx.) of ATP are gained for every glucose? Why is fermentation not efficient?
Definition
36-38
Not efficient because it produces ATP only by glycolysis.
Term
Summarize what happens in the Kelvin/Citric Acid Cycle (KCAC)
Definition
P.A. --> CO2, some ADP --> ATP. H atoms are provided for next step. Coenzyme NADH created via oxidization. Thiamine/riboflavin/niacin/pathothenic acid all essential
Term
What happens in the electron transport chain?
Definition
ATP generated using oxygen (Aeroic respiration)
Term
Summarize the electron transport chain process
Definition
NADH transfer H to EXC ( e-/p+ to carrier proteins), E- transferred NADH->O2, E- carried along EXC by carrier proteins, p+ shuffled out of cell (proton gradient created), aerobic respiration (carrier protein transferes 2 protons to oxygen to form water), ATP synthase allows outside protons in (proton motive force creates some ATP)
Term
What do hydrolic enzymes do?
Definition
Break bonds by adding water
Term
What do cellulases, amalayses and B-galactosidase digest?
Definition
Cellulose, starches, lactose (glucose+ galactose)
Term
What are fatty acids digested by?
Definition
B-oxidization reactions
Term
What breaks peptide bonds between amino acids? How are amino groups removed?
Definition
Proteases, Deamination
Term
Define genome
Definition
Complete set of genetic information for a cell
Term
Define gene
Definition
functional unit of genome
Term
Define gene product
Definition
gene encoded protein
Term
Define genetics
Definition
study of function and transfer of genes
Term
Define genomics
Definition
study and analysis of nucleotide sequencing of DNA
Term
Define DNA replication
Definition
DNA duplication before cell division
Term
Define expressed
Definition
decoded DNA information
Term
Define translation
Definition
interprets information carried by RNA to synthesize encoded protein
Term
Define transcription
Definition
copies info in DNA to RNA
Term
What is the central theory of molecular biology
Definition
flow of information from DNA->RNA->Proteins
Term
Define retrovirus
Definition
RNA genome that copies information in form of DNA
Term
DNA has a _' and _' end, the strands are ______. Seperating the strands is ____.
Definition
3, 5, antiparallel, denaturing
Term
With regards to RNA, what is a "transcript"?
Definition
A fragment of RNA synthesized from DNA
Term
What is the function of mRNA
Definition
Encodes proteins
Term
DNA replication is _____, as each of the 2 newly created DNA strands is half original and half new DNA
Definition
Semi conservative
Term
What is the function of DNA Gyrase?
Definition
temperature breaks DNA down
Term
What is the function of DNA Ligase?
Definition
joins DNA, forms covalent bond between sugar and P of adjacent nucleotide
Term
What is the function of DNA Polymerase?
Definition
synthesizes DNA helix ahead of replication fork
Term
What are Okazaki Fragments?
Definition
nucleic acid fragments that are generated during the discontinuous replication of amino acids
Term
What is the origin of Replication?
Definition
region of DNA where replication begins
Term
What is the function of Primase?
Definition
synthesizes small RNA fragments to serve as primers for DNA synthesie
Term
What is a Primer?
Definition
nucleic acid fragment to which DNA polymerase can add nucleotides
Term
What is the Negative (-) strand
Definition
DNA template strand, for RNA synthesis, RNA is complementary
Term
What is the Positive (+) strand
Definition
strand complementary to negative, RNA analogous
Term
Define Promoter
Definition
nucleotide sequence to which RNA polymerase binds to begin transcription
Term
Define Sigma factor
Definition
component of RNA polymerase that recognizes promoter region
Term
Ribosome Binding Site
Definition
sequence of nucleotides to which ribosome bonds
Term
Define monosistronic
Definition
Transcript carrying only one gene (poly=multiple)
Term
What is a core enzyme?
Definition
RNA polymerase without a sigma factor
Term
What happens in termination?
Definition
Terminator encountered, ribosome falls off
Term
What happens during transcription initiation?
Definition
At start codon, initiation complex forms
Term
What happens during transcrption elongation?
Definition
Ribosome has 2 sites (P/A). Initiating tRNA binds to P, tRNA recognizing next codon binds to A, enzyme binds with peptide bond, translocates one codon, tRNA released through E (exit) site
Term
What happens during transcrption termination?
Definition
Stop codon encountered, enzymes called release factors free tRNA
Term
What are the function of chaperones?
Definition
Help fold protein into final shape
Term
How are proteins meant to travel outside the cell differentiated?
Definition
Signal sequences added at the ends (tagged for export)
Term
What are spontaneous mutations
Definition
Mutations that occur in a cells natural enviornment in an exteremely (1 in 10k to 1 in 1T)
Term
Define reversion
Definition
The random reverseal of mutation (to a non mutated form)
Term
Define base substitution
Definition
Incorrect base incorporation into DNA
Term
Define silent mutation
Definition
A base changes but due to degenerate gene code, new codon specifies same amino acid
Term
Define missense mutation
Definition
New codon specifies new amino acid. Leaky - cell grows slowly, as encoded protein still partially works
Term
Define nonsense mutation
Definition
New codon is stop, protein truncated
Term
Define null/knockout mutation
Definition
Inactivates gene
Term
What is used to increase the frequency of base mutations?
Definition
Reactive forms of oxygen
Term
Why is adding 1 or 2 bases worse than 3?
Definition
Frame shift mutation if 1 or 2 added/removed -- causes ALL following codons to be wrong
Term
Chemicals that affect _________ _______ in DNA will result in higher mutations
Definition
Hydrogen Bonds
Term
Define intercalcating agents
Definition
Mutagens that fit between N bases in DNA and distort the structure
Term
How do UV rays affect DNA?
Definition
Cause covalent bonds to form between adjacent thiamine bases (thiamine dimers)
Term
How do X rays affect DNA?
Definition
Cause single and double strands to break (lethal deletions)
Term
What keeps the mutation rate in DNA low, aside from a low frequency of occurance?
Definition
DNA repair (pre or post replication), if heavy damage SOS repair
Term
Define DNA-Mediated Transformation
Definition
Genetic exchange allowing DNA to move bacterium
Term
How does DNA enter bacteria cells?
Definition
Binds to receptor cells on "competent" (state requiring high bacteria concentration, etc.) cells, one strand enters, other is degraded by nucleases
Term
How does donor DNA integrate into the host genome?
Definition
Homologous recombination - If donor DNA has a homologous region in cell genome, it will take its place
Term
What does transduction allow?
Definition
Bacterial DNA to transfer to another bacteria, mediated by bacteriophage
Term
Define phage
Definition
DNA/RNA with protein coat, infect by injecting nucleic acid
Term
Describe the process of transduction
Definition
Injection, nucleic acid removes host DNA, phage coat proteins synthesize, phage DNA replicates, some phage heads envelope bacterial DNA and infects another cell, bacterial DNA integrates into chromosomes by homologous recombination
Term
What does conjugation allow?
Definition
Bacterial DNA transfer, requires physical contact (bacterial sex)
Term
What does conjugation involve?
Definition
Mobilization of DNA transfer, plasmid transfer, synthesis of functional plasmid inside recipient/donor cells
Term
Light of a _______ wavelength will provide better resolution because these \waves can more easily fit between individual objects in the specimen.
Definition
Shorter
Term
True of False: Differential media suppresses the growth of unwanted bacteria but promotes the growth of wanted bacteria
Definition
False
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