Micro Exam 2

Arrangements of cocci

-diplococci -streptococci -tetrads -sarcinae -staphylococci

Describe how fungi reproduce

-Can reproduce both sexually & asexually -Almot all repeoduce asexually by producing spores (haploid cell) These then form into Hyphae (thread like filaments that make up the body of a fungus) -Asexual = genetical identical -Yeasts don't produce spores but reproduce asexually by budding -Sexual reproduction involves mating between 2 haploid hyphae. The 2 hyphae fuse forming a zygospore -Sexual= genetically different

Plasmodium

-Causes malaria (carried between people by mosquitoes vectors) - Is an apicomplexan which is a type of protozoan characterized by a form of asexual reproduction called schizogany -Has 6 stages and the gametocytes of one strain trigger changes in body chemistry attracting mosquitos to bite -Some genetic traits increase resistance to malaria

Three basic shapes of prokaryotic cells

-Coccus -Bacillus -Spiral (spirilla & spirochete)

Entamoeba

-Constitute second kingdom of amoebas distinguished from rhizaria by having lobe-shaped pseudopods & no shells. -Live inside animals where they produce potentially fatal amebic dysentery

Three methods of culturing viruses

-Culturing viruses in plants & animals -Culturing viruses in embryonated chicken eggs (vaccines can also be prepared in eggs) -Culturing viruses in Cell (Tissue) -consists of cells isolated from an organism & grown on the surface of a medium or in a broth

Streptomyces

-Ecologically they recycle nutrients in the soil by drgrading carbs including cellulose, lignin & chitin -Medically they produce most of th inportant antibiotics, including chloramphenicol, erythromycin & tetracycline -Gram positive

List 3 characteristics all fungi have in common & explain how they benefit the environment

-Eukaryotic -Multicellular -Heterotrophs -Essential recyclers in the enviornment as they are decomposers and breakdown organic material and restock the environment with usable nutrients

List 3 characteristics that all algae have in common & explain how they benefit the environment

-Eukaryotic -Photoautotrophic -have sexual reproductive structures -Consume (absorb) CO2 as they grow, releasing O2 into the air

Pseudomonas

-Gram negative, aerobic, flagellated, straight or slightly curved rods that catabolize carbs by entner- Doudoroff & pentose phosphate pathways -noted for ability to breakdown organic compounds (oil, rubber, plastic) - Class gamma proteobacteria -Can cause UTIs, external otitis (swimmers ear), & lung infections in CF patients

Dinoflagellates

-Group of unicellular, flagellated, alevolate protozoan characterized by photosynthetic pigments such as carotene & chlorophylls -Chromosome lack histone proteins -Make up a large portion of freshwater & marine plankton -Have 2 flagella of unequal length -Many are bioluminescent -Some produce neurotoxins (Gymnodinium & Gonyaulax) by exposure of shellfish

Rhizobium

-Grows within the roots of leguminous plants, such as peas, beans,& clover stimulating formation of nodules on their roots -These cells within nodules make ammonia available to plant -Nitrogen fixing alphaproteobacterium

Dimorphic

-Having two forms. Dimophic fungi have both yeastlike and mold like bodies -Generally the yeast form of a diamorphic fungal pathogen causes disease whereas the filamentous form doesn't

Mycobacterium

-High G+C gram positive bacteria -Composed of aerobic species that are slightly curved or straight rods that can form filaments -grow very very slow -waxy outer (acid fast stain is used) -Diseases: tuberculosis, leprosy

Nucleocapsid

Capsid + Nucleic Acid

Mycoplasma

Class of low G+C bacteria that lack cytochromes, enzymes of the krebs cycle, and cell walls. They are pleomorphic, and are gram negative -Can survive withour cell walls bc they colonize protected habitats such as animal & human bodies & bc of tough cytoplasmic membranes many of which contain sterols -Are associated with pneumonia & UTIs

Explain the characteristics used to classify viruses

Classification of viruses by the type of nucleic acid, presence of an envelope, shape, and size

Tetrads

Cocci divided into 2 planes, resulting in 4 cocci remaining attactched

Sarcinae

Cocci divided into 3 planes to form cubodial bundles

Diplococci

Cocci that remains attached in a pair

Virion

Completely assembled virus -virus outside of a cell, consisting of a proteinaceous capsid sureounding a nucleic acid core

Viroids

Extremely small, circular piece of RNA that is infectious & pathogenic in plants

Streptococcus

Gram positive cocci associated in pairs & chains. -Cause numerous diseases including: pharyngitis, scarlet fever, impetigo & pneumonia -flesh eating streptococci produce toxins that destroy muscle & fat tissue

pleomorphic

In cell morphology, term used to describe a variably shaped prokaryotic cell

Differentiate between latency (caused by proviruses) & persistent infections

In latent viruses, they are only produced during reactivation

Budding

In prokaryotes & yeasts, reproductive process in which an outgrowth of the parent cell receives a copy of the genetic material, enlarges, and detaches.

Bacillius (genus)

Includes endospore forminf aerobes & facultive anaerobes -Bacillus Thuringiensis (Bt toxin) is benefical to farmers/gardners bc during sporulation produces a crystalline protein that is toxic to caterpillars that ingest it -Bacillus Anthracis causes anthrax

lysogenic cycle (lysogeny) of the lambda phage

Replication cycle in which infected host cells grow & reproduce normally for many generations before they lyse. 5: induction happens when chemical agents that damage DNA molecules are introduced such as UV light

spore formation

Reproductive cell of actinomycetes and fungi at the ends of filamentous cells. Contains complete genetic information and can develop into a clone of the original organism

What characteristics do Rickettsias, Legionella, and Chlamydias have in common?

Rickettsias: Is a genus of small, gram negative aerobic rods that live & reproduce inside mammal cell. Require a host/vector or else they die. Causes mountain fever Chlamydias: small, gram negative cocci that grow & reproduce in the cells of mammals. Requires intracellulad life (a host) to survive Legionella: intracellular pathogen. Causes Q fever

Bacillus

Rod-shaped prokayotic cells

Differentiate between a virus & a virion

Virus: inside cell, is a nucleoprotein particle, can be Dna or Rna, protein covering coat called capsid, has a larger size. Infects all types of organisms Virion: outside cell, is an infection Rna particle, protein coat is absent, smallar size infects only plants

4 methods of prokaryotic reproduction

-binary fission -spore formation -snapping (form of binary fission) -budding

Some virions have a phospholipid membrane called _______ that surrounds the viral capsid

Envelope

Arrangements of bacilli

*Bacilli are less varied in their areangements than cocci because bacilli divide transversely* -single bacillus -diplobacillus -streptobacilli -palisade -V shape

List 3 characteristics that all Protozoa have in common & explain how they benefit the environment

-All are eukaryotes (they have a nucleus) -They can be parasitic -They all perfer aquatic or moist environments -Most a motile

Toxoplasma

-Apicomplexan -Causes toxoplasmosis Go back

Trichomonas (Protozoa)

-Are unicellular flagellated leaf shaped parabasalid protozoan parasites of animals & humans -Only one species is pathogenic (Trichomonas vaginalis) which causes an STD called trichomoniasis

Enterobacteriaceae

-Live in the gut of animals and can be harmless, beneficial, or pathogenic -Escherichia coli ( E. Coli) -researchers frequently use this bacteria for lab studies of metabolism, genetics, and DNA tech. -gram negative -straight soild rods, flagella or non motile

Cryptosporidium

-Protozoan, banana shaped, motile sporozoite that has an apical complex of organelles specialized for penetrating host cells making it apicomplexan -Form thick shelled oocysts which are the infective stage inside cells -Causes Cryptosporidosis -about 30% of ppl carry it asymptomatically

Vectors

-arathropds: Carry pathogens, segmented bodies, hard external skeletons, jointed legs. -arachnids -insects

Difference between Archaea and Bacteria

-archea cells do not contain peptidoglycan unlikd bacteria -unlike bacteria, archaea can survive extreme environments -unlike archea, bacteria is commonly found everywhere -Archea has many shapes, unlike bacteria which commonly has 3

Staphylococcus

-Typically found growing harmlessly in clusters in the nasal passages -A variety of toxins & enzymes allow some trains of S. Aureus to invade the body and cause diseases such as: bacterium, pneumonia, wound infections, food poisoning. -Some strains can become resistant to anitbiotics Is low G+ C gram positive

Explain how viral entry differs between phages & animal viruses.

-direct penetration: some non envelope virus enter, virus directly binds to receptor on host cell and injects viral nucleic acid into host cell like the polio virus -membrane fusion: Some envelope viruses enter, viral envelope fuses with host cell membrane and entire virus enters host cell, virus removes capsid once inside host cell. Ex measles and mumps virus -endocytosis: most non envelope and some envelope virus enter this way. Virus binds to receptor in host cell binding stimulates host cell to take virus via endocytosis. Entire virus enters; once inside remove envelope/coat. Ex herpes virus -uncoating: upon enterence of host cell, virus will uncoat by removing capsid & unmasking the nucleic acid inside

Compare protozoan trophozites and cysts

-trophozite: The motile feeding stage of a protozoa . One forms a cyst which later becomes one trophozite -Cyst: hardy resting stage characterized by a thick capsule and a low metabolic rate. Not reproductive structures. Allows intestinal protozoa to pass from one host to another & to survive harsh environments

Lytic replication cycle of the T4 bacteriophage

1) Attachment- nonmotile, contact occurs by random collision. Tail fibers are responsible for attachment of T4 to its host bacterium. Attachment proteins on the tail fibers pricisely fit to complementary receptor proteins on their host cells. Attachment can be very specific 2. Entry- Once T4 has attached to bacterium's cell wall it must overcome formidable barrier posed by cell wall and cytoplasmic membrane. It does this by releasing lysozyme, a protein enzyme carried within the capsid that weakens the peptidoglycan of the cell wall. The phages tail then contracts, forcing an internal hollow tube within through cell wall/membrane (like a puncture) phage then injects its genome through tube & into bacterium. The empty capsid is left behinf outside of cell. After entry viral enzymes beginn degrading bacterial DNA 3. Synthesis- After losing its chromosome, the bacterium stops synthesizing its own molecules & begins synthesizing only viral parts under control of viral genome. For dsDNA viruses (T4), protein synthesis is similar to cellular transcription & translation except that mRNA is transcribed from viral DNA instead of cellular DNA. Translation by hosts cell ribosomes result in viral proteins and lysozyme 4. Assembly- As capsomeres accumulate within the cell, they spontaneously attach to one another to form new capsid heads. Tails assemble & attach to heads & tail fibers attach to tails forming mature virions. The process requires little or no enzyme activity. Capsids can assemble around leftover pieces of host DNA instead of viral DNA through a process known as transduction 5. Release- Newly assembled virions are released from the cell as lysozyme works on the cell wall and the bacterium disintegrates. The whole process for T4 lytic replication takes about 25 min & can produce 100-200 new virions for each bacterial cell lysed.

Describe the role of algae in atmospheric gas production

1/2 of O2 production

The arrangements of prokaryotic cells result from

2 aspects of division during binary fission: the planes in which cells divide & whether or not daughter cells remain attached to each other

Viral shapes (description)

3 basic types: Helicial, polyhedral, complex

Staphylococci

A cluster of cocci resulting from random cell divison

binary fission

A form of asexual reproduction in which one cell divides to form two identical cells. -The parental cell disappears

coccobacillus

A prokaryotic cell intermediate in shape between a sphere and a rod.

Capsid

A protein coat surrounding the nucleic acid core of a viron

Capsomere

A proteinaceous subunit of a capsid

vibrios bacteria

A slightly curved rod-shaped prokayotic cell

spirilla (spirillum)

A stiff spiral-shaped prokaryotic cell

snapping division

A variation of binary fission in gram positive prokaryotes in which the parent cell's outer wall tears apart with a snapping movement to create the daughter cells -the daughter cells then remain hanging together almost side by side, held at an angle by a small remnant of the original outer wall that acts like a hinge

Cyanobacteria (blue-green algae)

Are gram negative phototrophs that vary greatly in shape, size and method of reproduction -are typically coccoid or disk shaped. Coccal forms can be single or arranged in pairs, tetrads, chains or sheets. Disk shaped forms are often tightly appressed to form filaments that can either be straight, branched, or helicial. -Photosynthesis by cyanobacteria is thought to have transformed then anaerobic atmosphere of the early Earth into our oxygen containing one.

Methanogens

Are obligate anaerobes that convert CO2, H2, and organic acids into methane gas (CH4) which is the major component of natural gas. These microbes constitute the largest known group of archaea in the phylum Euryarchaeota. -Play a significant role in the environment by converting organic wastes in pond, lake, and ocean sediments into methane.

Clostridium

Are rod-shaped, obligate anaerobes, many of which form endospores. Is gram positive. Produce potent toxins that can cause a variety of diseases due to the endospores. -Examples: C. Tetani = tetanus, C. Perfringens= gangrene, C. Botulinum = botulism, C. Difficile = severe diarrhea

How do prokaryotes reproduce?

Asexually

A virus that infects and usually destroys bacterial cells is called

Bacteriophage

Hyphae

Each of the branching filaments that make up the mycelium of a fungus.

Saprobe

Fungus that absorbes nutrients from dead organisms -Most fungi

Streptococci

Long chains of cocci

Spirochete

Long, rod-shaped bacterium that is twisted into a flexible spiral.

Listeria

Low G +C gram positive rod shaped. -Listeria monocytogens contaminates milk & meat products. Continues to reproduce under refridgeration & can survive inside phagocytic wbcs -rarely causes disease in adults but can kill a fetus in an infected woman when it crosses placental barrier -can also cause meningitis & bacteremia

Extremophiles

Microbe that requires extreme conditions of temperature, pH, and/or salinity to survive

Halophile

Microorganism requiring a saline environment (greater than 9% NaCl)

Thermophiles

Microorganism requiring temperatures above 45 degrees Celcius. Prokaryotes that require temps above 80 C are called hyperthermophiles

Describe helminths & why they are studied in microbiology

Muticellular parasitic worms with organ like systems -Are studied because they are capable of causing disease & parasitic infections involve eggs & larvae which are microscopic

Lactobacillus

Non-spore-forming rods normally found in the human mouth, stomach, intestinal tract & vagina. -rarely cause disease, instead protect the body by inhibiting the growth of pathogens -used as probiotics found in yogurt, buttermilk, pickles, sauerkraut & kombucha

Prions

Proteinaceous infectious particle that lacks nucleic acids & replicates by converting similar normal proteins into new prions -responsible for "Mad Cow Disease" can cause a similar disease in humans. can be transmitted by consumption of dried or cooked food.

V-shape & Palisade

Snapping division causes daughter cells to remain attached to form V-shapes and folded side by side arrangements called-Palisade

coccus (cocci)

Spherical prokaryotic cells

Chitin

Strong flexible nitrogenous polysaccharide found in fungal cell walls & in the exoskeletons of insects & other anthropods

Mycelium

Tangled mass of hyphal filaments composing the vegetative body of a fungus.

Describe the role of algae in microbial media

The gel-like polysaccharides agar & carrageenan, once isolated from red algae such as Gelidium, are used as thickening agents for the production of soild micro media

Burst size

The number of new virions released from each lysed bacterial cell

Burst time

The period of time required to complete the entire lytic process from attachment to release

Describe the role of algae in the food chain

They act as food providing energy for other organisms. Most producers are phytoplankton or microscopic floating plants

Are viruses alive?

They are the least complex living entities. Outside cells they do not appeae to be alive but within cells they direct the synthesis and assembly required to make copies of themselves

Virus

Tiny infectious acellular agent with nucleic acid (either DNA or RNA) surrounded by proteinaceous capsomeres that form a coverinf called a capsid