LAB EXAM 3 Flashcards
Dark repair
Encludes different repair enzyme
Does not require light
Cuts the damage section
Later repaired by DNA polymerase 1 and DNA ligase.
Uv light experiment
UV light effects growth by interfering with DNA resulting in thymine dimer formation.
The dime fixation is confined with in adjacent thymine resides in same strand.(intrastrand)
These dimmer lesions have consequence on DNA functions including interference with DNA replication, transcription.
Fungi
They are heterotrophs and saprophytes.
Some are parasites
Cell wall made of chitin( target for anti fungal agents) is present
Majority of fungi are aerobes or facultative anaerobes.
Few are obligate anaerobes
Fungi prefers to grow at acidic pH( 5or lower)in high salt and sugar in slight moist environment and relative humidity of 70% or more.
They have a filament ours body( mycelium); individual filament is called hypha.
Hyphae are well adapted to absorb food
High surface to volume ratio
Releases enzymes to breakdown food;also acts as a repellant.
Specialized hyphae
Included haustoria and rhizoids
Haustoria: are associated with parasitic fungi
Rhizoids:are associated with saprophytic fungi
Aggressive vs. gentle nature of hyphae
Dimorphic fungi
Are ones which can grow as both yeast like ( unicellular) or as mycelia; human pathogenic fungi are dimorphic
Coliforms
Enteric gram negative bacteria that ferment lactose to gas and are found in intestinal tracts of animals and humans.
They ferment lactose generating acid and gas. Coliforms include Enterobacter aerogenes and Ecoli.
They are normal resident of gastrointestinal tract. And are representative indicator associated with fecal contaminated water.
Light repair
A light activated enzyme breaks pyramidine to pyrimidine bonds.
The enzyme: photolyase
Restores original DNA sequence
Anti fungal drugs
A. Affects membrane component:
Polyenes: includes Amphotericin and Nystatin
- binds to ergosterol component, results in leaky membrane
- very toxic; limited use in life treating conditions
Azoles
Includes clotrimazole and miconazole
- inhibit ergosterol sythesis; interfere in the synthetic pathway
- active component of medications( over the counter) used to treat localized superficial yeast infections.
Fungi- heterotrophs
An organism deriving its nutritional requirements from complex organic substances.
Rhizobia- Sporangiophores
Asexual sporangiophores are produced by sporangia at the end of elevated sporangiophores.
Rhizopus-zygospore
Two compatible mycelia fuse. Upon germination, a zygospore produces colonies that are genetically different from either parent.
Fungus- rhizopus
Grows as filamentous, branching hyphae that generally lack cross walls. They produce by forming asexual and sexual.
They are found in a wide variety of organic substrates.
Infections may also be a complication of diabetic ketoacidosis. This widespread genus includes at least eight species.
Anti- fungal drugs
B. Cell wall synthesis
Echinocandins(ex Caspofungins) used for candida and Aspergillosis treatment.
Interferes with fungal cell wall sythesis
Anti- fungal
Cell division
Gresiofulvin ( synthesized by some fungi)
-exact mechanism, unknown
Thought to interfere with spindle fibers component ( tumblin) and blocks mitotic events.
Used in treatment of nail and skin fungal infections.
Anti- fungal
Nuclei acid sythesis: poor target
flu cytosine: taken by yeast cells and converted into active, inhibitory form, 5 fluorouracil ( inhibits nuclei acid synthesis).
Antimicrobial- General action of various anti microbial a used in the class experiment.
Hydrogen peroxide:
Is a common household chemical that can disinfect and even sterilize the surfaces of inanimate objects. Such as contact lenses.
Commonly mistaken to treat open wounds.
Does not make good antiseptic because catalase an enzyme real eased from damaged human cells.quickly neutralize hydrogen peri oxide by breaking it down to water and oxygen.
Phenol
To reduce infection during surgery. Phenol naturally occurring molecule that is also carbolic acid. Phenolics, which are compounds synthesized from phenol have greater Antimicrobial efficiency with fewer side effects.
Denature proteins and distrupt cell membranes in a wide variety of pathogens.
Vomit, pus, saliva, and feces, and they remain active of the surface for a long time.
Silver nitrate
Zinc, Mercury, copper, are Antimicrobial because they combine with sulfer atoms in molecules of cysteine, and amino acid.
Such binding denatures proteins, inhibiting or illuminating their function.
To prevent blindness caused by N. Gonorrah
Betadine
Medically iodine used either as a tincture or as an iodophor, which is iodine- containing organic compound that slowly releases iodine.
Betadine is an example of iodophor used in medical institutions to prepaid for skin surgery.
Bleach
Household bleach diluted by adding two drops to a liter of water can be used in emergency to make water safer to drink. It does not kill all protozoan cysts.
Chlorine is the main component.
The dairy industry and tester rants use these compounds to disinfect utensils, and the medical field uses them to disinfect hemodialysis systems.
Coliform bacteria and their detection:
The two most frequent contaminants found in canned foods are Clodtidium.
Low acid foods
Clostridium is especially problematic because of the cans and jars not heated sufficiently, the endospores germinate, grow? And release toxins inside the sealed container.
Fecal coliforms
Represented by Ecoli they are normal residents of the gastrointestinal tract.
Durham tube
The role of a Durham tube is to place broth to which the samples will be inoculated contains small glass tube to trap gas produced as lactose metabolism continues.
Concept of presumptive and confirmed test.
Presumptive test: done in theDurham tube to see if gas production has taken place from the lactose fermenting.
Change to yellow from red. And presence of air bubble in Durham tube.
Concerned test:an EMB plate is used to confirm presence of fecal coliforms which exclusively originates I decal contaminated water. EMB is to observe colonies.
FUNGUS
Sporangia
Is an enclosure where spores are formed. It can be composed of single cell or can be multicellular. All plants, fungi, and many other lineages firm sporangia at some point in their life cycle.
FUNGUS- spinangiospores
Are spores that are produced in a sporangium. A sporangium in fungi is simply cell containing spores
FUNGUS-Zygospore
Is a diploid reproductive stage in the life cycle of many fungus and Protists.
Zygospore said are created by nuclear fusion of haploid cells.
A zygospore remains dormant while it waits for environmental cells.such as light moister and heat.when the environment is favorable, the zygospore germinated meiosis occurred, and haploid vegetative cells are released.
Fungal spores
Fungus reproduce with spores not usually pathogenic in humans,
Bacteria spores
Endospores it’s function is to protect the DNA in harsh conditions.
Transmission of GIARDIA
Is a microscopic parasite
Found on surfaces or in soil, food, or water that has been contaminated with feces from infected humans or animals.
Disease associated: intestinal infection by abdominal cramps, bloating, nausea and bouts of watery diarrhea.
Transmission- TRYPANOSOMA
Transmitted by the bite of an infected tsetse fly and are most common in rural areas.
Though a process known as antigenic variation some trypanosomes are able to encase host cells immune system by modifying their surface membrane
Infiltrates central nervous system
Transmission- TRICHOMONAS
Sexually transmitted infection
It’s caused by a single called protozoan parasite.
Infection of the urogenital tract
Urethra and vagina in woman
Transmission- Clonorchia
Eggs are small encapsulated, yellowish brown - turn into->
Swimming cercacriae released into fresh water and transform into metacercariae.
When these infected fish are invested by humans/ animals, the larvae are released into the duodenum, which then migrate to the bile ducts, can mature to adulthood w/ in 30 days.
Transmission- LEISHMANIA
Sand flies transmit Leishmaniz parasites.
Humans also transmit parasite between each other through blood transfusion or shared needles.
Transmission- TRICHINELLA
Transmission only occurs through the consumption of animal meat infected with pathogenic cysts, encasing larvae.
Animals in close contact with rodents such as domestic hogs. Are at high risk of contracting infection.
Transmission- SCHISTOSOMA
Parasitic flatworms
Responsible for highly significant group of infections in humans
Contact with water in households children and woman get it.
Diseases associated with
TRICHOMONAS
Vaginitis
Infection is in the urthra
Disease- PLASMODIUM
Infection with plasmodia is known as maleria, a deadly disease widespread in the tropics.
Disease- GIARDIA
Intestinal infection marked by abdominal cramps, bloating, nausea, and bouts of watery diarrhea.
Disease- BLANTIDIUM
Causes serious disease of the gastrointestinal tract.
Explosive diarrhea
Colon may also occur in acute infections which can lead to life treating situations.
Disease/ Leishmania
Transmitted by sandfly/ parasite
Disease is in skin and internal organs
Disease- TRICHINELLA
Myocarditis, central nervous system involvement
Pain and weakness followed by slow progression of symptoms.
Vectors- TRYPANOSOMA
Tsetse fly spreads parasite to human and animals
Vectors- LEISHMANIA
Sand flies
Humans also transmit I between others blood transfusion
Vectors- PLASMODIUM
Bites of mesquites
IMBiC test, its importance
The test are a group of individual tests used in microbiology lab testing to
Simmons citrate agar and its use?
Determine the ability of a microorganism to use citrate as a sole carbon source.
The agar contains citrate and ammonium ions
( nitrogen source) and bromothymol blue as an indicator.
The citrate agar is green before inoculation. And turns blue as a positive test, meaning that the citrate is utilized.
Indole test
The organism under consideration is grown in peptone water broth. It contains tryptophan, which under the action of enzyme tryptophanase is converted to an idole molecule, puruvate and ammonium.
The indole is then extracted from the broth by means of xylene.
To test the broth for indole production, Kobac’s reagent
A positive is shown by the presence of a red violet color in the surface alcohol layer of
Mannitol salt agar medium
Selective and differential
Salt/ selective for gram positive
Mannitol fermenting indicator
Distinguishing pathogenic in a short period of time.
Gives halo as a PH indicator
Hemolysins
Are lipids and proteins that cause lysis of red blood cells by destroying their cell membrane.
3 Hemolysins
Alpha, beta, gamma
Alpha- incomplete- dark green
Beta- complete- yellow
Gamma-unchanged - no color change
Erythromycin
Act by binding to the 50s subunit of prokaryotic ribosomes and preventing the elongation of the nascent protein.
Teracycine
Get in between the tRNA and ribosome.
Streptomycine
Inhibit protein synthesis by irreversibly binding to the 50s subunit of prokaryotic ribosomes.
Causing the ribosome to mistranslate mRNA, producing aberrant proteins or causing premature release of ribosome from mRNA, which stops synthesis.
Penicillin
Binds to deactivate the enzyme that cross links to the NAM subunits of peptiglycan
Chromophenicol
Large subunit
Neomycin
Inhibit protein synthesis by irrervisibly binding to the 30s subunit of prokaryotic ribosomes
This either causing the ribosome to mistranslate mRNA
Producing aberrant proteins, or causing premature release of the ribosome from mRNA
Which stops sythesis also bactericide by distroying outer membranes of G-bacteria.
Butamediol pathway
Further metabolizes butanediol.
This metabolism does not react to the methyl red test in airway that refleets the production of butamidol detection by the Voges- Proskvair test.
Plasmodium
Malaria
Mosquito
TRYPANOSOMA
Tsetse fly
Anemia, cardiovascular problem and kidney disorders,
The disease may lead to extreme exhaustion and fatigue.
TRICHOMONAS
T vaginitis
Sexually transmitted
Male
Female
Leishmania sps
Sand fly
Tropical
TRICHINELLA
Undercooked meat
Spiral large in the skeletal muscle
SCHISTOSOMA
Has a unique lateral spine.
Taenia sps
2 species
Beef- four suckers
Pork-round with hooks
Indole test
Tryptophanase breaks down tryptophan into indole.
Reacts with kovac’s agent to get red color.
Citrate utilization
Citrate- breaks down to exciloacte
Citrase permease- transport sodium citrate through cell.
