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Flashcards in Chapter 3 Deck (92):
1

virus

has aa capsid, and from 1 to several hundred genes in the form of DNA or RNA in the capsid; not

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capsid

protein coat

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envelope

lipid rich, viruses surround themselves with them , contains virus specific proteins

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viruses; living organisms

don't metabolize nutrients, can't reproduce by themselves, can have DNA or RNA but not both, don't have a cell wall or a membrane

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viral infection

1. virus absorbs chemical receptor site on the host (chemical receptor is a specific glycoprotein) 2. nucleic acid of the virus penetrates into a cell, in bacteriophages nucleic acid is normally injected through the tail after viral enzymes have digested a hole in the cell wall. in

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endocytotic

most viruses that infect eukaryotes are englufed via this process

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lytic infection

virus takes over the cell's reproductive machinery and begins reproducing new viruses. cell fills with new viruses until it bursts

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eclipse period

brief period before the first fully formed virion appears

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latent period

perfiod from infection to lysis (includes eclipse period)

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virulent virus

virus following the lytic cycle

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lysogenic infection

viral DNA is incorpoated in to the host genome, or if the virus is RNA and it posses the enzyme reverse transcriptase (then DNA is reverse transcribed from RNA and then incroporated in the host cell). so when the host cell replicates its DNA the viral DNA is replicated as well

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temperate virus

virus in a lysogenic cycle

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dormant or latent

viral DNA is incorporated in the host DNA and is called a provirus

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plus strand RNA

proteins can be directly translated from the RNA (unenveloped)

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retro viruses

enveloped plus strand RNA // carries the enzyme reverse transcriptase

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minus strand RNA

is the complement to mRNA and must be transcribed to plus RNA before being translated

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types of viruses

double stranded RNA and single and double stranded DNA viruses

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viriods

small rings of naked RNA, only infect plants

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prions

cause infections in animals, capable of reproducing themselves

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vaccine

either injection of antibodies or an injection of a non patheogenic viruse with the same capsid or envelope

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carrier population

more than one animal may carry the virus thus it could be transferred back to humans

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prokaryotes

don't have a membrane bound nucleus, most are in the domain bacteria

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archaea

more in common with eukaryotes, extreme environments, cell walls not made of peptidoglycan

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fixing CO2

all microorganisms, reducing CO2 and using the carbon to create organic molecules

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autotrophs

capable of fixing CO2 as their sole source of carbon

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heterotrophs

get carbon from organic matter

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phototrophs

use light as an energy source

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chemotrophs

use oxidation of organic and inorganic matter

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nitrogen fixation

N2 converted to ammonia

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nitrifcation

creates nitrates from ammonia

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nucleoid

RNA, DNA and protein complex in prokaryotes, not enclosed by a membrane

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cocci

round shaped bacteria

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bacilli

rod shaped bacteria

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sprilla

helically shaped bacteria

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ribosomes

prokaryotes have them, translate proteins,

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mesoomes

invaginations of the plasma membrane

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inclusion bodies

granules of organic or inorganic matter that may be visible under a light microscope

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plasma membrabe

surrounds the cyotosol of nearly all prokaryotes by a phospholipid bilayer

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phoshpholipid

phosphate group, 2 FA chains and glycerol backbone (baloon with two strings), molecules is amphipathic

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micelle

polar ends toward the soultion, nonpolar ends toward each other

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prokaryotes plasma membrane

doesn't have steroids, some have steroid like molecules

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integral/intrinsic proteins

traverse the membrane from the inside of the cell to the outside

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peripheral or extrinisic proteins

situated on the surfaces of them membrane -- ionically bonded to integral proteins or the polar group of the lipid

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fluid mosiac model

membrane is fluid, parts can move laterally but cannot separate , asymmetrical layout of its proteins, hopanoids probably reduce fluidity. in eukaryotic membranes cholesterol modertaes membrane fluidity

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diffusion

occurs in the direction of lower concentration

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chemical concentration gradient

a gradual change in concentration of a compound over a distance, series of vectors pointing in the direction of lower concentration

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electrical gradient

points in the direction that positively charged particle will tend to move

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electrochemical gradient

chemical and electrical gradient combined

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semipermeable

slows diffusion for a particle but doesn't stop it

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aspects of a compound and semipermeability

size and charge -- bigger less permeable and more polar less permeable

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passive diffusion

molecules move through leakage channels across the channel due to random motion

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transfer or carrier proteins

help move molecules that are too big or too charged to passively diffuse across the membrane

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facilitated diffusion

diffusion occur down electro-chemical gradient of all species involved

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selectively permeable

facilitated diffusion makes membranes ___ because it is able to select between molecules of similar size and charge

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active transport

movement of a compound against its electrochemical gradient, requires ATP

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secondary active transport

using ATP to create e-c gradient and then using the energy of e-c gradient to acquire or expel a molecule

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bacterial envelope

surrounds the protoplast

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protoplast

bacterial plasma membrane and everything inside it

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cell wall

component of the envelope, adjacent to the plasma membrane, prevents cell from bursting

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hypertonic

cytosol is more concentrated than aq solution surrouding them

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isotonic

same amount of particles

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hyootonic

cytosol contains less particles

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peptidoglycan

cell wall made of, disaccharid polymer chains with AA, 3 of which aren't found in proteins, chains are continuous, more elastic than cellulose, porous

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gram sgram staining

stains two major clel wall types differently

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gram positive bacteria

thick peptidoglycan cell wall, prevent gram stain from leaking out, appear purple

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gram-negative bacteria

appear pink when gram stained, thin peptidoglycan cell wall, outside the cell wall they have phospholipid bilayer (more permeable)

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slime layer

wraps bacteria, can be washed off

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pili

short tenacles, can attach a bacterium to a solid surface, not involved in cell motility

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flagella

long, hollow, rigid, helical cyclinders made from the globular protein flagella, rotate counterclockwise to propel bacterium in one direction, move clockwise-- bacteria tumbles -- allow bacteria to change orientation and go in a new direction, propelled using energy from a protein gradient

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genetic recombination

how bacteria get new genes

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binary fission

two DNA polymerase begin at origin of replication, move in opposite direction making single strands that combine with template strands to form two complete DNA double stranded circles, cell then divides -- cells are gentically identical

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conjugation

one bacteria needs to have a plasmid with the gene that codes for the sex pilus , plasmids are small circles of DNA, need to have a conjugative plasmid to initate conjugation , sex pilus is a hollow protein tube that connects two bacteria to allow for the passage of DNA, connects the cell that has the conj, plasmid to the one that doesnt, a strand of the plasmid is nicked and one of the strand separates from its complement the loose strand is then replicated and fed through the pilus

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F plasmid

fertility factor of F factor ( have it = F+), if pilus is made while the F factor is integrated into the chromosome some or all the rest of the chromosome may be replicated and transferred

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R plasmid

resistance to antibiotics

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transformation

bacteria incorporate DNA from their external environment into their genome

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transduction

when virions infect a new bacterium and they inject harmless DNA instead of virulent viral DNA fragments

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vector

virus that mediates tranduction

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endospores

gram positive bacteria lie dormant for ears, resistant to heat, UV radiation, chemical disinfectant and desications, , bacterium divides within its cell wall , has to be activated before it can germinate and grow -- activated by heat and germination is triggered by nutrients

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fungi

distinct kingdown with three divisions-- NOT PHYLA -- eukaryotic heterotrophs obtains food by absorption, secrete their digestive enzymes outside their bodies and then absorb the products of digestions.// don't distinguish between living and dead matter - -can be potent pathogens

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saprophytic

live off dead or organic matter

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septa

cell walls made of chitlin(polysacchirde)

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chitlin

more resistance to microbial attack than cellulose

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zygomycota

don't have a cell wall

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yeast

unicellular fungi

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fungi cont

don't have centrioles, mitosis happens in nucleus, nuclear envelope never breaks down

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mycelium

tangled mass growth state of fungi

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hyphae

branched thread-like stuctures

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fungi growth state

haploid stage predominate, hyphae are haploid

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reproductive structures

release haploid spores -- give rise to new mcelia in asexual repoduction

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yeast

rarely produce sexually by producing spores -- asexual reproduction occurs by budding (cell fission)

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sexual reproduction fungi

between hyphae from two mycelia of different matting type + and = -- grow toward on another, eventually touch and make a conjufation bridge.

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deciding between types of reproduction

sexual reproduction-- times are tough | asexual reporudction -- times are good