Microbiology Exam 2 Flashcards

eukaryotic cell evolved when larger prokaryotic cell engulfed smaller prokaryotic cells.

-locomotor appendage

-long, cylinder containing microtubules

-covered by an extension of the cell membrane

-locomotor appendage

-shorter than flagella

- found only in certain protozoa and animal cells

-function: motility, feeding, filtering

- outermost boundary that comes in direct contact w/ the environment

-composed of polysaccharides

-functions: adherence, protection, signal reception

rigid, provides structural support and shape

-bilayer of phospholipids and proteins

-serves as a selectively permeable barrier in transport

-functions in interaction and surface adhesion, secretion, and signal transduction

-most prominent organelle of eukaryotic cell

-nuclear envelope composed of two parallel membranes

-contains chromosomes

-function: packaging and transport

-function: nutrient processing, synthesis, lipid storage

-”central receiving”

-function: modifies, stores, and packages proteins

-composed of flattened sacs called cisternae

nucleus → RER → Golgi → vesicles → secretion

-vesicles containing enzymes that came from the Golgi apparatus

-function: intracellular digestion of food particles, protection against invading microbes

membrane bound sacs that contain particles for digestion, excretion, or storage

vacuoles merged with a lysosome

-function: energy production and storage of ATP

-function: convert the energy of sunlight into chemical energy through photosynthesis

-found in algae and plants

-function: protein synthesis

-composed of rRNA and proteins

-function: anchoring of organelles, movement of cytoplasm, amoeboid motion, transport, structural support

-unicellular or colonial

-heterotrophic

-parasitic fungi = mycoses

-microscopic:

• hyphae: long filamentous fungi/molds (vegetative: digest/absorb nutrients; reproductive: produce spores)

• yeasts: round ovoid shape, asexual reproduction, have cell wall, lacks locomotor appendages (pseudo hypha: chain of yeasts)

-CA: pneumocystis jiroveci

-Epidemiology: asymptomatic, 30-40% who get it have HIV/AIDS

-Pathogenesis: inhaled spores attach to alveolar walls, they fill with fluid, walls thicken impairing oxygen exchange.

-Symptoms: shortness of breath, slight fever, non-productive cough

-Treatment: trimethoprim sulfamethoxazole (TMP-SMX)

-CA: sporothrix schenkii (dimorphic fungi)

-Types:

• cutaneous (skin): most common form, occurs on hand/arm after touching plant

• pulmonary (lung): rare, inhalation of spores

• disseminated (those w/ HIV): infection spreads to another part of the body

-Epidemiology: warmer temp. climates, handlers of thorny plants

-Symptoms: chronic ulcers at site of puncture

-Pathogenesis: spores introduced to wound, pimple develops and enlarges

-Diagnosis: physician obtains swab/biopsy

-Prevention: protective clothing, no vaccine

-Treatment: oral itraconazole (3-6 months); those w/ severity = lipid formulation of amphotericin B, SSKI for cutaneous.

formed by successive cleavages called sporangium.

free spores not enclosed by a sac.

-isolation on specific media

-macroscopic and microscopic observation

-adverse:

• mycoses, allergies, toxin production

• destruction of crops and food storages

-beneficial:

• sources of antibiotics, alcohol, organic acids, vitamins

• decomposers of dead plants/animals

• making food

• genetic studies

-CA: Coccidiodes immitis

-Epidemiology: inhalation of arthrospores, 40% are symptomatic, California/Arizona/S.America,

-Symptoms: resembles TB, coughing, chest pain, fever, weight loss, flu-like, rash

-Pathogenesis: inhalation of spores, tissue damage

-Diagnosis: blood sample, chest x-rays, CT scans, tissue biopsy

-Treatment: clears up on own, oral azoles: ketoconazole (FDA approved), fluconazole (meningitis), IV amphotericin B

-eukaryotic

-protist

-unicellular, colonial, filamentous

-cell wall

-may or may not have flagella

-photosynthesize w/ chlorophyll

-eukaryotic

-protist

-unicellular

-lack a cell wall

-free living

-heterotrophic

-lack tissues

-free living

-function: provide basis of food in aquatic habitats, produce oxygen

-have locomotor appendages (flagella, cilia, pseudopods)

-trophozoite: motile feeding stage

-asexual reproduction + sexual reproduction

-CA: Giardia lamblia

-Facts: lack mitochondria +peroxisomes, has ER, Golgi, cytoskeleton, and flagella, seen by Leeuwenhoek

-Epidemiology: fecal/oral transmission, ingestion of cysts from contaminated water, more prevalent in kids, most frequently diagnosed intestinal parasitic disease in the US.

-Pathogenesis: cysts emerge as trophozoites in colon, attach to bowel, feeds on mucus and reproduce.

-Symptoms: 40% show lactose intolerance, frothy diarrhea, dehydration, weight loss, vitamin deficiencies.

-Treatment: Flagyl (metronidazole), tinidazole, nitazoxanide

-Prevention: boil water, filter water

-CA: Plasmodium falciparum

-Epidemiology: “world’s greatest health problem,” 40% are @risk

-Pathogenesis: vector carried (anopheles sp. mosquito), mosquito bites infected person→ picks up gametes → sexual reproduction → bites non-infected person

-Symptoms: flu-like, anemia, jaundice

-Treatment: chloroquinone

-pathogenic protozoa

-long, crescent-shaped cell w/ single flagellum

-occur in blood during infection

-transmitted by vectors

Ex:

• T. brucei = african sleeping sickness

• T. cruzi = chagas disease

-infective amoeba

-Entamoeba histolytica - amebic dysentery

• Symptoms: gastrointestinal disturbances

-parasitize host tissues

-have mouths for attachment

-have well developed sex organs

• Flatworms

• Roundworms

-identified pathogens

-filterable agent cause of certain diseases

-obligate intracellular parasites

-need a host

-ultramicroscopic

-do not independently fulfill characteristics of life

-structure: capsid surrounding nucleic acid core

-Genome is either dna OR rna

-lack enzymes and machinery for protein synthesis

-no resemblance to cells

-capsid

-envelope (not in all viruses)

-nucleic acid molecule (DNA or RNA)

-matrix proteins

-crystalline appearance

- all viruses have capsids

• Helical - helix, rod-shaped

• Icosahedral - 3D, symmetrical polygon w/ 20 sides (dice), may/may not have envelope

  • Rotavirus

  • Norovirus

-mostly in animal viruses

-spikes: exposed proteins essential for attachment of virus to host cell

-protects the nucleic acid

-dissolves in alcohol

-atypical virus

-lack capsid and are covered by lipoproteins and fibrils.

-have bacteriophages

-DNA or RNA, never both

-carries genes necessary to invade host cell

-make new viruses

• DNA- ds, ss

• RNA- ss, ds

  • ssRNA ready for translation: postive-sense

  • ssRNA needing conversion: negative-sense

-polymerases: synthesize DNA or RNA

-replicases: copy RNA

-reverse transcriptcase: synthesis of DNA from RNA

-CA: Influenza A and B

-Facts: enveloped polymers of hemagglutinin (HA) and neuraminidase (NA), mutations: antigenic drift [strain in geo. area)/shift [different strain, same host])

-Symptoms: flu-like

-Pathogenesis: kills epithelial cells, HA binds to host cell, NA hydrolisizes mucus releasing new virions

-Epidemiology: adults shed flu virus from the day before symptoms begin, occur during fall/winter months

-Treatment: Tamiflu, Relenza

-Prevention: nasal mist, intramuscular injection

-type

-microscopic appearance

-anatomical/geographic area

-effects on host

-acronyms blending several characteristics

binding of virus to specific molecules on the host cell.

genome enters the host cell

the viral nucleic acid is released from the capsid

viral components are produced

new viral particles are constructed

assembled viruses are released by budding (exocytosis) or cell lysis

-CA: Rabies virus

-Facts: rod-shaped, negative sense linear RNA genome, zoonotic, exposure through bite from rabid animal

-Pathogenesis: virus → bite → neurons → nervous system to brain → rapid replication → salivary glands

-Symptoms: flu-like, weakness, cerebral dysfunction, anxiety, confusion, agitation, delirium, hallucinations

-Prevention: vaccination of pets/people

viral envelope fuses directly with host membrane by lipid rearrangement

entire virus is engulfed in a vacuole.

the nucleus

the cytoplasm

cell damage altering microscopic appearance

-cell harbors the virus and is not lysed.

• herpes simplex virus

• herpes zoster virus

- animal virus enters host cell and permanently alters its genetic material resulting in cancer

• papillomavirus - cervical cancer

• Epstein-Barr virus - Burkitt’s lymphoma

-bacterial viruses (phages)

1. Adsorption – binding of virus to specific molecules on
host cell
2. Penetration – genome enters host cell
3. Replication – viral components are produced
4. Assembly – viral components are assembled
5. Maturation – completion of viral formation
6. Lysis & Release 

completion of viral infection through lysis and release of virions

-spread of the virus without killing the host cell

• Corynebacterium diphtheriae

• vibrio cholerae

• clostridium botulinum

1. isolate and identify viruses in clinical specimens

2. prepare viruses for vaccines

3. allow for research on structure and effects

test tubes

• cell (tissue) cultures

alive

• bird embryos

• live animal inoculation

-misfolded proteins, contain no nucleic acid

-resistant to sterilization

-causes transmissible spongiform encephalopathies

-common in animals

• Creutzfeldt Jakob Syndrome

process by which chemical compounds are acquired from the environment to sustain life.

basic requirements of life

-carbon

-hydrogen

-oxygen

-phosphorus

-nitrogen

-sodium

-magnesium

substance an organism must get from a source outside its cells

-required for large amounts (macro)

-plays a role in cell structure and metabolism

• ex: proteins, carbohydrates

-required for small amounts (micro)

-involved in enzyme function and protein structure maintenance

• ex: manganese, zinc, nickel

(must contain carbon and hydrogen atoms)

-methane

-carbohydrates

-lipids

-proteins

-nucleic acids

(combo of atoms that are NOT carbon and hydrogen)

-magnesium sulfate

-sodium phosphate

-O2

-CO2

-H2O

1. carbon

2. hydrogen

3. oxygen

4. phosphorus

5. sulfur

6. nitrogen

proteins

must obtain carbon in an organic form made from other living organisms

organism uses CO2 as its carbon source

they lack the genetic and metabolic mechanisms to synthesize them.

gain energy from chemical compounds

gain energy through photosynthesis

1.oxygenic photosynthesis

-produces O2

-chlorophyll is the primary pigment

• ex: plants, algae, cyanobacteria

2.anoxygenic photosynthesis

-production of sulfur

-bacteriochlorophyll is the pigment

• ex: purple/green sulfur bacteria

survive only on inorganic substances

• ex: Venenvibrio

methanogens

• ex: Methanocaidococcus jannaschii

-heterotroph

-free living microorganisms that feed on organic detritus from dead organisms

• ex: opportunistic pathogens, facultative parasites

-heterotroph

-obtains nutrients from living or nonliving source

• ex: obligate parasites

-doesn’t require energy

-higher concentration → lower concentration

• diffusion

• osmosis - diffusion of H2O

• facilitated diffusion - solutes requiring a carrier

-requires energy and carrier proteins

-gradient independent

• carrier-mediated active transport

• group translocation

• bulk transport - endo/exo/pino cytosis

water concentration is equal inside and outside the cell

net diffusion of water into the cell

-water diffuses out of the cell

-shrinkage if the cell membrane (plasmolysis)

they bind and transport only a single type of molecule

the rate if transport limited by the number of binding sites on transport proteins

1.membrane-bound transport proteins interact w/ solute-binding proteins

2.ATP is activated and generates energy to pump solute into the cell.

bringing substances into the cell through a vesicle/phagosome

ingests substances or cells (pseudopods)

ingests fluids and/or dissolved substances (microvilli)