Microbiology: Microbiology: Exam 3 notes** Flashcards

These are the 'hint' questions & information for Exam 3. Given by Mrs. Edelman

They are chemoheterotrophs & acuire food by absorption. With the exception of yeast, fungi are multicellular. Most reproduce w/sexual & asexual spores.

chemoheterotrophs

absorption

multi

sexual & asexual

* Can produce sexually & asexually
* they are photoautotrophs
* Produce several different photosynthetic pigments.
*Obtain nutrients by diffusion
* some are multicellular, forming colonies, filaments, or even tissues.
* A few produce toxins

They belong to several

PHOTOAUTOTROPHS

photosynthetic pigments

diffusion

Yes. A few do produce toxins

* most are chemoheterotrophic, but few are photoautotrophic
* obtain nutrients by absorption & ingestion.
*ALL ARE UNICELLULAR
* MANY ARE MOTILE
* Parasitic protozoans often form resistant cysts.

several

Chemoheterotrophic BUT few are photoautotrophic

absorption & ingestion

UNI

resistant cysts

MOTILE

the separation of substances (such as serum proteins or DNA) by their rate of movement through an electrical field.

An IDENTIFICATION scheme based on sucessive paired questions; answering one question leads to another pair of questions, until the organism is identified.
* WIDELY USED FOR IDENTIFICATION

A dichotomous phylogenetic tree that branches repeatedly, suggesting the classification of organisms based on the time sequence in which EVOLUNTIONARY branches arose.
* Each branch point, or node, in the cladogram represents an ANCESTOR COMMON TO ALL SPECIES BEYOND THAT NODE.

* Cells are in a cluster (like grapes)
* Is catalase POSITIVE
* Does not need enriched media for growth
* Are found on skin

* Cells are in a string or chain
* Is Catalase NEGATIVE
* Needs enriched media for growth
* Are found in respitory tract.

Definitive- harbors sexually reproducing stages of Plasmodium.

Intermediate- The host in which the parasite undergoes asexual reproduction.

Brown & green algae are not toxic.

Cryptospordium is a protozoan parasite in the phylum

They are UNICELLULAR algae collectively called plankton, or free-floating organisms. Their rigid structure is due to cellulose embedded in the plasma membrane. Some dinoflagellates produce neurotoxins.
* A TOXIC ALGAE

neurotoxins (called saxitoxins) that cause paralytic shellfish poisioning (PSP) & ciguatera.
* A TOXIC ALGAE

Transmitted between humans through ingestion of cysts; excreted by feces. Found in human intestine.

African sleeping sickness (T. brucei). T. Cruzi is trasmitted by the kissing bug (some cases in Tucson Az).

-has no mitochondria- & is sometimes called G. intestinalis or G. ductenalis. Excreted as a cyst in feces & survives in the environment before being ingested by next host. Diagnoses of giardiasis (disease caused by G. lambia) is often based on the identification of cyst in feces.

Naeglria
* IF YOU DRINK A GLASS OF WATER INFESTED W/NAGELERIA, OR UNTREATED TAP WATER. A PERSON CAN GET INFECTED BY AMOEBA BY GETTING WATER IN THE NOSTRILS OR FECAL CONTAMINATION

Is the only ciliate that is a human parasite. The causative agent of severe, though rare, type of dysentery. When the host ingests cysts, they enter the large intestine, into which the trophozoites are released.

A multiNucleated mass of protoplasm, as in plasmodial slime molds. * when written as genus, refers to the causative agent of MALARIA!!
Takes place in the liver & in the red blood cells of a human host.

as special class of DNA-cutting enzymes that exist in many bacteria.
The different cuts are:
Blunt ends- both strand are cut in the same place
Sticky ends- cuts that leave staggered ends

recognizes & cuts, or digests, only one particulary sequence of nucleotide bases in DNA & it cuts this sequence IN THE SAME WAY EACH TIME.

Is a monomer of DNA nucleotides & polymer is knowN as polynucleotide.

Is a monomer of DNA nucleotides & polymer is known as polynucleotide.
*synthesizes a complementary strand of DNA, creating a double-stranded piece of DNA containing the information from the mRNA

Is a genetic way of changing RNA to DNA
* PCR uses viral RNA or a cell's mRNA as the template. The enzyme, reverse transcriptase, makes DNA from RNA template, & the DNA is then amplified.

REVERSE TRANSCRIPTASE to synthesize complementary DNA)(cDNA) from an mRNA template.

Plasmids (most common vector) & viruses can be used as vectors. Most important property of a vector is the ability to self-replicate once in a cell.

A different kind of vector can usually accept much larger pieces of foreign DNA than plasmids can. After the DNA has been inserted into the viral vector, it can be cloned in the virus's host cells.

depends on many factors, including the organism that will receive the new gene & the size of the DNA to be cloned. * must self-replicate once in a cell.

Plasmid are one of the primary vectors in use, particularly variants of R factor plasmids. Plasmid DNA can be cut w/the same restrictions enzymes as the DNA to be cloned, so that all pieces of the DNA will have the same sticky ends.

* to make multiple copies of a pieces of DNA enzymatically.
* to AMPLIFY DNA to detectable levels
* want to make multiple copies of DNA you need (PCR)
* cannot amplify an entire genome

gel electrophoresis.

a. real-time

b. quantitative

Is an enzyme that produces RNA in cells.

Is an enzyme used to covalently link the backbones of the DNA pieces, producing an rDNA molecule.

1. Human Insulin
2. Human growth hormone
3. Human blood clotting
4. Transgenic farm animals
* it is Gram-negative*

A gene from a vertebrate animal, including a human, can be inserted into the DNA of a bacterium, or a gene from a virus into a yeast may be used. In many cases, the recipient can then be made to express the gene, which may code for a commercially useful product.
* BY INSERTING THE INSULIN INTO A SUITABLE VECTOR, THE E.coli bacterial cell, TO PRODUCE AN INSULIN THAT IS CHEMICALLY IDENTICAL TO ITS NATURALLY PRODUCED COUNTERPART. This has been achieved using Recombinant DNA technology.

Each of the 2 synthetic genes was inserted into a plasmid vector & linked to the end of a gene coding for the bacterial enzyme ß-galactosidase, & chemically joined to make human insulin

Capitalize the first letter & underline when writing or italicize when printing the whole name:
example: Salmonella truphimurium or S. truphimuirum (all in italics),

Lack of nuclear membrane- all prokaryotes are unicellular.

Putting organisms into categories to show degrees of similarties among organisms.
* Science of CLASSIFYING organisms
* Provides universal names
* Provides a reference for identifying organisms

is the science that studies serum & immune responses that are evident in serum organisms are antigenic; that is, microorganisms that enter an animal's body stimulate it to form antibodies.

-IDENTIFY BACTERIAL SPECIES & STRAINS BY determining their susceptiblitiy to various viruses (or phages)-
Can differentiate not only among microbial species, but also among strains within species. Serological testing was used to determine whether the increase in number of cases of necrotizing fascitis in the U.S & England since 1987 was due to common source of infections.

A population of cells arising from a single parent cell.

If a double-stranded molecule of DNA is subjected to heat, the complementary strands will separate as the hydrogen bonds between the bases break. If the single strands are then cooled slowly, they will reunite to form a double-stranded molecule identical to the orgiinal double strand. (This renunion occurs because the single strands have complementary sequences.) WHEN THE ABOVE TECHNIQUE IS APPLIED TO SEPARATED DNA STRNDS FROM 2 DIFFERENT ORGANISMS, IT IS POSSIBLE TO DETERMINE THE EXTENT OF SIMILARITY BETWEEN THE BASE SEQUENCES of THE 2 ORGANISMS. THIS METHOD IS nucleic acid hybridiztion.

WHEN THE ABOVE TECHNIQUE IS APPLIED TO SEPARATED DNA STRANDS FROM 2 DIFFERENT ORGANISMS, IT IS POSSIBLE TO DETERMINE THE EXTENT OF SIMILARITY BETWEEN THE BASE SEQUENCES of THE 2 ORGANISMS. THIS METHOD IS nucleic acid hybridiztion.

Oomycotes grow in fresh water that causes diseases to fish and terrestrial plants. It forms the cottony masses on dead algae and animals.
* so called water molds & downy mildews. They are filamentous protists which must absorb their food from the surrounding water & soil, or may invade the body of another organism to feed.
"oomycota" means "egg fungi" & refers to the large round oogonia, or structures containing female gametes

a technique by which small samples of DNA can be quickly amplified, that is, increased to quantities that are large enough for analysis.

1) Archaea

2) Bacteria

includes most of the proterobacteria that are capable of growth at VERY LOW LEVELS OF NUTRIENTS.
* Some have unusual morphology, including protrusions such as stalks or buds known as prosthecae.

1. Pelagibacter
2. Azospirillum
3. Acetobacter & gluconbacter
4. *Rickettsia- Spotted fever / Rocky Mountain spotted fever.
5. *Ehrlichia- gram(-)transmitted by ticks, can be fatal.
6. Caulobacter & Hyphomicrobium
7. Rhizobium, Bradyhizobium & Agrobacterium
8. *Bartonella- gram(-) causes cat scratch disease
9. *Brucella- gram(-) invades our body's defenses WBC's
10. Nitrobacter & Nitrosomonas
11. Wolbachia

gram (-) & rod shaped known as the spotted fever, transmitted by rat fleas.
*Obligate intra cellular parasites
*reproduce only within mammalian cells

gram (-)live obligately within WBC's. Transmitted by tick to humans & cause ehrlichiosis, SOMETIMES FATAL.

contains several members that are human pathogens. Best known is Bartonella henselae(italics),gram(-) bacillus that causes CAT SCRATCH DISEASE.

Bacteria are small nonmotile coccobacilli. All species of Brucella (italics) are obligate parasites of mammals & cause the disease brucellosis. Brucella survive phahocytosis, an important element of the body's defense against bacteria.

often use nutrient substances that diffuse away from areas of anaerobic decomposition of organic matter, such as hydrogen gass, ammonia & methane.

Thiobacillus
Spirillum
Sphaerotilus
*Burkholderia- Grows on hospital equipment & disinfectant solutions.
*Bordetella- whooping cough
*Pseudomonas
* Legionella
* Coxiella
* Vibrio
*= ones we need to remember for exam

was formerly grouped w/the genus Pseudomonas, which isnow classified under gammaproteobacteria. Like the pseudomanads, almost all burkhlderia (italics) species are motile by single polar flagellum or tuft of flagella.
*grow on hospital equipment & disinfectant solutions.

gram (-) * whooping cough
Of special importance is the nonmotile, aerobic, gram (-)rod Bordetella pertussis(italics) This is serious pathogen is the cause of pertussis, or whooping cough.

*very important, consist of aerobic gram (-) rods that are motile by polar flagella cause,

common in streams & they colonize such habitats as warm-water supply lines in hospitals & water in the cooling tower of air conditions systems. Ability to survive & reproduce within aquatic amoebas often makes them difficult to eradicate in water systems.

Coxiella burnetii(italics) which causes Q fever
* requires a mammalian host to cell reproduce.
* not transmitted among humans by insect or tick bites
*TRANSMITTED BY aerosols or contaminated milk.

are rods that are often slightly curved. One important pathogen is Vibrio cholerae(italics) causative agent of cholera.
*profuse water diarrhea
*inhabits coastal salt waters it is transmitted to humans mostly by raw or undercooked shellfish.

slender gram (-) rods that are helical or curved. Motile by means of flagella & are microaerophilic.
*Campylobacter- one polar flagellum. C.fetus (italics) causes abortion.
*Helicobacter- curved rods w/multiple flagella most common for peptic ulcers & a cause of stomach cancer.

highly pleomorphic because they lack a cells wall & can produce filamints that resemble fungi, hence their name (mykes=fungus).
M. pneumonia, which is the cause of the common mild pneumonia.

Garnerella vaginalis (italics) is a bacterium that causes one of the most common forms of vaginitis.

consists of facultative anaerobes that are found in the mouth & throat of humans & animals. *actinomyces israelii causes actinomycosis, a tissue-destroying disease usually affecting the head, neck & lungs.

mophologically resembles actinomyces; however, these bacteria are aerobic. To reproduce, they form rudimentary filaments, which fragment into short rods.
can cause:
*chronic, difficult to treat pulmonary infection
*mycetoma- localized infection of feet or hands.
~common in soil.