Microbiology Exam 2

sterilization

disinfection

non-pathogenic cells

sanitization

from pathogen to pathogen

antiseptics

mechanism of action

damage to proteins and dna, altering of membrane permeability, and slowing down metabolism

wet heat, heavy metals, radiation, etc

phenolics and quats

insert themselves into the membrane and form holes that ruin membrane integrity

bacteriostatic - cold and dessication

physical or chemical

altering the physical environment

heat, cold, radiation, desiccation, osmotic pressure, filtration, soaps/detergents

employ some kind of chemical attack

phenolics, halogens, alcohols, heavy metals, aldehydes, quats, peroxides

denatures proteins

hot water or steam

boiling, autoclaving, pasteurization

10 minutes

use steam under pressure to denature proteins

121 celsius for 15 minutes (15 psi)

coxiella burnetii

home and commercial canners

retorts; commercial sterilization

endospores of clostridium botulinum

121 celsius for 15 min (15 psi)

inadequately processed hoe canned foods

kills by burning

fire or hot air

incineration

less

160 celsius for 120 min

glass and metal

incinerator for biological wastes

incinerated to make sure endospores are destroyed

bacillus anthracis

flaming loops

slows metabolism

freezing, refrigeration

bacteriostatic

refrigeration temperatures

listeria monocytogenes

pathogens

psychrotrophs, refrigerated food spoilage

psuedomonas fragi

damages dna

ionizing and non-ionizing

gamma rays, x rays, electron beams

UV

knock electrons off of atoms

gamma rays and xrays

cobalt-60

surface air treatment (hospitals)

260nm

dna absorbs uv rays best at this wavelength

thymine dimers

changes shape of dna molecule, which causes enzymes that make dna copies to malfunction

UV lights to disinfect the air

UV light and HEPA filter

slows metabolism

dehydrating or drying foods

bacteriostatic

all organisms require water, when moisture becomes too low enzymes no longer function and metabolism stops

less than 20%

spoilage

bacteria

cheese and bread, they grow in dry areas better than bacteria

draw water out of cells and cause plasmolysis

high levels of sugar/salt in foods like jellie, james, honey, syrup, salty meat

staphylococcus aureus

more than 7%

removes microbes

operating rooms, biological safety hoods, membrane filters

high-efficiency particulate air filters

to filter air

99.97% of 0.3 micrometers (most bacteria are >1 micrometer)

decrease surface tension

microbes are allowed to be lifted up and carried off

germicidal action

make it easir to rub and rinse away microbes on surfaces

approved by meeting government regulations

EPA

FDA

environmental protection agency

food and drug administration

pesticides, drugs

endospores and mycobacteria; waxy mycolic acid coat

eukaryotic

viruses

• endospores
• mycobactera
• cysts of protozoa
• vegetative protozoa
• gram-negative bacteria
• fungi (including fungal spores)
• non-enveloped viruses
• gram-positive bacteria
• enveloped viruses

envelope

disrupt cell membranes

thymol, triclosan

mycobacteria

listerine

antibacterial handsoaps and detergents

triclosan

inhibit proteins

fluoride, chlorine, hypochlorite (HOCl), iodine, iodophors

toothpaste (~1000ppm)

treat drinking water (~1ppm)

bleach (5% hypochlorite)

prepping skin before an injection

iodine combined with detergents

prepping areas before surgery (disinfect and have cleaning action)

inhibit proteins, dissolve lipids

ethanol

household disinfectant (rubbing alcohol)

injection prep

soaking metal spatulas

passed through flame to burn off alcohol

70% (some water is required in order to denature proteins)

inhibit proteins

silver, copper

drops of 1% silver nitrate

neisseria gonorrhoeae infections, passed during birth

erythromycin

the rise in chlamydia trachomatis eye infections, silver nitrate couldn't effectively kill it

treat swimming pool water (prevent algal growth) and grapes (prevent fungal growth)

inhibit proteins

formaledhyde

effect even against endospores

carcinogens

aldehydes, suspected carcinogens

to embalm bodies or preserve biological specimens

15%

disrupt cell membranes

benzalkonium chloride

alkyl dimethy benzyl ammonium chloride

non toxic

eyewash solutions

lysol, fantastik, household sanitizers

lysol

cause various oxidation reactions

hydrogen peroxide (h2o2)

hydrogen peroxide

benzoyl peroxide

singular, circular; multipl, linear

4.6 million; 4,300; yes

3.4 billion; 20,000

plasmids

toxins or resistances to antibiotics/disinfectants

replication, transcription, translation, genetic recombination

copy of chromosome is made

rna is made using information in dna

proteins are made using information in rna

segments of dna are transferred from one chromosome to another

cytoplasm, specifically the nucleoid

nucleus

a specific sequence of nucleotides recognized by the replication enzymes

multiple

new chromosome copies remain attached to proteins in cell membrane, this allows copies to seperate during binary fission

spindle fibers move chromosomes around during mitosis

dna helicase and dna polymerase

uncoils the dna helix and seperates the two strands

lays down the new nucleotides and forms new strands of dna

okazaki fragments

proteins

cytoplasm

nucleus

rna polymerase

rna polymerase binds to the dna at the promoter, then seperates the two strands of dna and begins reading dna in one strand, it attaches rna nucleotides according to the nucleotide sequence in dna, and the rna molecule lengthens

introns

segments of rna that must be removed in order to produce the proper protein later during translation

yes

there is no time to remove introns

translation usually begins before transcription ends (before rna is finished being made, ribosomes are already grabbing it and trying to make proteins using the information already there)

nucleus, cytoplasm

ribosomes

part protein and part RNA

thousands

three

codons

a specific amino acid that will be added to the protein

AUG or the start codon

by pieces of tRNA (transfer rna)

it reaches one of the three stop codons, then the ribosome disnegages and the new protein is released

mRNA, tRNA, and rRNA

contains the dna message and is the piece of RNA that the ribosome reads

delivers the new amino acids to the ribosome

forms part of the ribosome (the rna part)

bacterial transcription and translation aren't seperated by compartments

change in the nucleotide sequence of dna

spontaneous or mutagens

errors made by dna polymerase during replication

chemical or physical agents that cause dna polymerase to make mistakes

dna polymerase has a self-checking ability and other enzymes (repair enzymes) patrol dna and detect unusual shapes

radiation or chemicals

gamma rays, xrays, uv

aflatoxins, ethidium bromide, 5-bromouracil

260 nanometers

by changing the shape of the dna molecule

aspergillus flavus

aflatoxins

peanuts, corn, and wheat

stain gels after electrophoresis

to seperate dna fragments during dna fingerprinting

to the dna and is used to located where the bands of dna occur

in lab to cause mutations for experimental research

to treat cancer

dna polymerase, photolyass, and endonucleases

a proof-reading function

light, break thymine diners and allow thymines to reattach to their original bases

cuts out affected nucleotides after thymine dimers and allows other enzymes to replace them

the ames test

a his (histidine negative)

salmonella typhimurium

• chemical being tested and rat liver extract are added to a tube containing salmonella typhimurium
• time is permitted for mutations to occur and then the mix is plated on an agar without histidine
• growth on agar means that mutations occured

most cells die due to lack of histidine in the media, but mutagens will now be allowed to produce their own histidine and will survive

chemicals are not mutagenic in their original form but converted to mutagenic compounds by liver enzyme

enzymes in rat liver produces a variety of molecules when mixed with original chemical, so it is a test of the original compound and all of its variations

exchange of dna between two chromosomes

dna travel from cell to cell because bacterial chromosomes are singular

transformation, conjugation, and transduction

update of naked dna from the environment

direct transfer of dna from one cell to another

transfer of dna from one bacterial cell to another by a bacteriophage (virus)

adding chemicals like mild detergents or passing an electric current through the solution (electroportation)

ruin it, but not enough to kill it hopefully allowing fragments of dna to pass through

through direct contact

using pilus to attach to the receiving cell and reel it into contact

genetically equipped with necessary structures

plasmids

copies are only given off during conjugation so both cells have this plasmid genes and they can pass them onto other cells

f factor in e. coli (f for fertility)

the ability to produce pilus

resistance factors

enzymes will cut up dna so when phage particles are being assembled pieces of bacterial dna may be packed in them

the process of inserting foreign genes into an organism (this is genetic recombination when it happens naturally)

recombinant dna (rDNA)

recombinant, transgenic, or engineered organism

• bacterial cells are processed and plasmids are collected
• seperately, cells with the gene you want to transfer are process and dna is collected
• plasmids and dna you want are cut open using enzymes and mixed together
• peices of dna with the gene you want will be inserted into some plasmids
• recombinant plasmids are inserted into new cells using transformation

transporters, plasmids

restriction enzymes

e. coli

saccharomyces cerevisiae (yeast)

used to engineer human cells for use in gene therapy

bacterial enzymes that destroy phage dna

specific nucleotide sequences (produce sticky ends)

short, single-stranded lengths; they tend to stick to complementary single strands

pieces of dna cut with an enzyme can be inserted into the dna of another organism that's been cut with the same thing, they have the same sticky ends

dna with the introns removed

eukaryotic genes from being inserted into bacteria, because they cannot remove introns themself

transcriptase, enzyme produced by retroviruses

we use reverse transcriptase to produce cDNA and that allows us to engineer bacterial cells with eukaryotic genes

genetic engineering of humans in order to treat disease

attenuated cirus

they already have the ability to penetrate human cells and release dna

adenoviruses (cause respiratory infections, like the common cold)

SCID (severe combined immunodeficiency)

leukemia

process that makes multiple copies of a piece of dna (usually billions) within a couple of hours

heating and cooling of temps between 60-95 degrees Celsius, temperatures that would denature dna polymerase from mesophiles

thermus aquaticus

taq polymerase

transformation, electroporation, microinjection, gene gun, viruses, and agrobacterium tumefaciens

a variation of transformation that uses an electric current to make the cell membrane leaky and allow dna to enter

dna can be injected directly into cells using an ultra-fine needle

animal cells and yeasts, it may be called microinjection but the needle is far too large for bacterial cells

microscopic particles of gold are coated with dna and fire at cells

eukaryotic

a plant pathogen that has the ability to inject dna into plant cells

gall

ti-plasmid (tumor inducing)

used to engineer crops with various traits (ability to produce own pesticide), the crops produce protein crystals that harm digestive tracts of insects but are harmless to animals and human

bacillus thuringiensis

bt crops (bt corn, bt cotton, etc)

to determine paternity, solve crime, trace outbreaks, and detect pathogens

cut up dna sample, copy it, seperate it, stain it, view it

pcr makes multiple copies of fragments

gel electrophoresis is used to seperate dna fragments according to length, electric current running through gel bath causes fragments to move through the gel, large fragments don't move far and small fragments do, this creates a fingerprint pattern

stained with ethidium bromide, dna gel is not visible so it must be stained to see, gel is soaked in a solution of ethidium bromide and the bromide wedges itself into the dna helix

ethidium bromide is fluourescent, so when gel is exposed to uv light the band becomes visible

compare dna of a known species to the unknown species

it's the same except that prokaryotes are not assigned to kingdoms

stains or serotypes

e. coli 0157:H7

enterobacteriaceae

bergey's manual

archaea, bacteria, and eukarya

20

proteobacteria, firmicutes, and actinobacteria

gram-negative

genera: escherichia, proteus, psuedomonas, neisseria, and salmonella

low GC gram-postive bacteria

clostridium, bacillus, lactobacillus, staphylococcus, and streptococcus

the percent of base pairs in an organisms dna are that are guanine-cytosine (GC is below 50%)

high GC gram-positive bacteria

filamentous

streptomyces and mycobacterium

100,00

eukaryotic

aerobic (molds/mushrooms), facultatively anaerobic (yeasts)

chemoheterotrophs

using spores (molds/mushrooms) or by budding (yeasts)

molds and mushrooms are multicellular and yeasts are unicellular

chitin

sterols (ergosterol)

saprophytes (nutrients from dead and decaying material)

saccharomyces cerevisiae (bread, beer, wine); candida albicans (yeast infections)

multicellular hyphage to make a mycelium

colored area in the center of a mold indicate spores

rhizopus stolonifer (black bread mold); penicillium (blue-green environmental mold)

both, either way they produce spores - if a spore lands in a suitable environment it germinates

mating types - they produce asexually unti they meet an opposing mating type them produce sexually

opposite mating types fuse together (plasmogamy), their nuclei remaind seperate for a period of time, later when stimulted they nuclei fuse (karyogamy)

below surface

a solid mass of hyphae produced during sexual reproduction; disperse spores

penicillium chrysogenum

cause disease, spoilage, and destruction

mycoses; yeast infectios caused by candida albicans

mycotoxins

less than 1%

one-fourth; rhizopus stolonifer, penicillium

mold growth in homes can require significant costs to replace damaged materials or remove toxins

stachybotrys chartarum, black mold that grows on wet building materials

anything from headaches to organ damage

no, no metabolism, reproduction, or cells

smaller than bacteria, measured in nanometeres, require a microscope to see

nucleic acid (rna or dna) and a protein coat (capsid)

ssDNA

dsDNA

cell membrane that the virus stole from the host cell when it escaped

spikes, attach to host cell

specific receptors on the surface of cells

bacteriophage

by using a living host, they can't be grown in sterile media; they are obligate intracellular parasites

in culture media with their bacterial host

fertilized chicken eggs

chicken eggs

attachment, penetration, biosynthesis, maturation, and release

physical attachment to host cell exterior, virus binds to a specific receptor which is usually a polysaccharide or a protein

movement of the virus from the exterior to the interior of the host cell

endocytosis, host cell membrane invaginates and surrounds the virus and brings it in the cell in a vesicle

endocytosis or fusion, the virus envelope melts into the host cell membrane

plant cell walls are tough so it only happens when plant cells are damaged (by insects or gardening tools)

injecting the genetic material intot he cell wall while phage is outside the cell

production of virion parts, production of new dna or rna and new capsid proteins

forms the whole mature virion

escape of virions from interior of cell to exterior, these infect new cells

by budding (obtains its envelope from the cell membrane as it is exiting)

when host cell becomes so full that it ruptures

a provirus

rna viruses

HIV, causes AIDS

they may never activate, but they are never removed and will call the viral dna as long as the cell is alive

virus remains dormant in host cells for long periods of time without symptoms

herpes viruses - remain latent inside nerves (cold sores, genital herpes, chicken pox)

cancer causing viruses

human papillomavirus (HPV) causes cervical cancer; hepatitis B (HBV) causes liver cancer

the insertion of a provirus disrupts an oncogene

a gene whose protein helps control cell division, cell can lose control over its cell division

10% of all human cancers

infectious proteins

spongiform encephalopathies, or spongy brain diseases

infections results in death of brain cells, causes brain to form and fill with fluid and gives the brain a spongy appearance

scrapie, mad cow disease (bovine spongiform encephalopathy, BSE), Creutzfeldt-Jakob disese, kuru

in sheep, this is where the first prion was discovered

by feeding cattle contaminated sheep parts

most common human prion disease, CJD may have originally been transmitted through contaminated beef infected with neural tissue

human in certain new guinea tribes whose burial practices involve eating parts of the deceased

normal brain proteins

eating meats contaminated with brain or spinal cord tissue

infectious rna

interfering with normal transcription/translation

plant viroids

potato spindle tuber disease, which causes potatoes to grow into an enlongated shape