Download Comparing Viruses, Bacteria, and Yeast - Cell Org, Size, Characteristics, Components and more Quizzes Microbiology in PDF only on Docsity!
Virus size Bacteria size Yeast
size
virus - 0.02 - 0.2 umBacteria - 0.2 - 5umyeast - >5um (3- 10um)human hair - 100umhuman eye can see 45um TERM 2
Fungi characteristics
DEFINITION 2 cellular organization - eukaryotic uni and multi cellularcell wall - presentmotility - nonmotilemicrobial members - molds and yeastcellular - yescell type - eukaryoticnucleic acids - DNA & RNAribosomes - 80Ssterols in membrane - present / ErgosterolOuter surface - rigid cell wall with chitin TERM 3
Prokaryote characteristics
DEFINITION 3 cellular organization - prokaryotic / unicellularcell wall - presentmotility - motile and nonmotilemicrobial members - bacteriacellular - yescell type - prokaryoticnucleic acids - DNA & RNAribosomes - 70Ssterols in membrane - absentouter surface - rigid cell wall w/ peptidoglycan TERM 4
virus characteristics
DEFINITION 4 submicroscopic (< 0.2 um) acellular "microbes and cant replicate on their owncellular - nocell type - infect prokaryotic and eukaryotic cells.nucleic acids - RNA or DNAribosomes - nonesterols in membrane - presentouter surface - protein capsid w/ or w/out lipoprotein envelope TERM 5
Bacterial Genome (total genetic
material)
DEFINITION 5 (A) bacterial chromosome double-stranded DNA attached to cytoplasmic membrane at mesosome single circular chromosome / HAPLOID(B) optional components (1) plasmids (2) bacteriophages (3) transposons Merodiploid means partially diploid always choose haploid unless merodiploid is an option
Plasmids
extrachromosomal ds DNA molecules (usually circular)may be transferred from one bacterium to anotheroften contain genes for antibiotic resistance and/or bacterial toxins TERM 7
bacteriophages
DEFINITION 7 viruses that infect bacteriamay integrate into the bacterial chromosome (LYSOGENY)may carry genes for toxins & hydrolytic enzymes TERM 8
Transposons
DEFINITION 8 self-mobile segments of DNAcan move readily from one site to another ("jumping genes")often carry genes for antibiotic resistance(Plasmids and transposons are the transmitters) TERM 9
Bacterial protein synthesis pathway
DEFINITION 9 similar to eukaryotic cellsDNA-dependent RNA polymerase TRANSCRIBES DNA into mRNA Ribosomes TRANSLATE mRNA codons & recruit tRNAsDifferences from eukaryotic:no nuclear membrane so entire process in cytoplasm of procaryotes70S vs. 80S ribosomes (specificity of protein synthesis antimicrobials) procaryotic mRNA may be monocystronic or polycystronic multiple ribosomes may process same mRNA molecule simultaneouslyProcaryotic50S + 30S = 70SEucaryotic60S + 40S = 80S TERM 10
Cytoplasmic Membrane
DEFINITION 10
- a bipolar phospholipid bilayer that surrounds cytoplasm- associated proteinsFunction(s) selective permeability site ATP production active transport in & out of cell site of synthesis for cell wall precursors
lipid A moiety
responsible for many symptoms of disease fever and hypotension septic shock TERM 17
repetitive polysaccharide or O-antigen
DEFINITION 17 may interfere with serum-cidal activities (i.e. antibody & complement)used for identification & epidemiology (i.e. Escherichia coli O157:H7) TERM 18
Recognition of Infection & Activation of Innate
Immune Responses - PAMPs
DEFINITION 18 PAMPs (pathogen-associated molecular patterns) peptidoglycan, teichoic acids, LPS, etc. unique to microbes (aka MAMPs) TERM 19
Recognition of Infection & Activation of Innate
Immune Responses - PRRs
DEFINITION 19 PRRs (pathogen recognition receptors ex. toll-like receptors) on defense cells, ex. macrophages causes production of cytokines tumor necrosis factor interleukins TERM 20
Recognition of Infection & Activation of Innate
Immune Responses - Cytokines
DEFINITION 20 Cytokines promote inflammation activation of complement pathways activation of coagulation pathwaysDuring minor infection = protectionExcess cytokines during severe infection = septic shock
endotoxin vs. exotoxins
only Gram-negative bacteria possess endotoxinboth Gram- negative & Gram-positive bacteria may secrete exotoxinsEndo is lipid and pollysaccharideExo is proteins TERM 22
endotoxin (LPS)
DEFINITION 22 cause of septic shock stimulates macrophages to produce tumor necrosis factor (TNF)Lipid A TERM 23
exotoxins (protein)
DEFINITION 23 usually destroyed by heat, inactivated by certain chemicals cause of primary clinical manifestation(s) of several diseases ex. erythrogenic toxin - rash & fever of scarlet fever tetanus toxin - violent muscle spasms, "lockjaw genes frequently carried by bacteriophages & plasmids ex. diphtheria toxin - bacteriophage tetanus toxin -plasmid inactivated exotoxins (toxoids) - basis for many vaccines ex. diphtheria & tetanus TERM 24
FIMBRIA / PILI
DEFINITION 24 fringe/hairs surround cell - > 100 per cell Function(s) adherence bacterial conjugation (sex) antiphagocytic TERM 25
BACTERIAL MOTILITY
DEFINITION 25 Flagella whip-like protein appendagesAxial filament (or periplasmic flagella) organelle of motility for spirochetes
