Microbiology: A Human Perspective Flashcards

Terms Definitions
dysuria
urgency
vaginosis
catheter
anuria
enuresis
products
final compounds
affinity
chemical reaction
jarisch-herxheimer reaction
ophthalmia neonatorum
toxic shock
papnaicolaou smear
electron donor
energy source
nucleoid
region containing DNA
diplococci
pairs of prokaryotes
Enzymes
without enzymes, energy-yielding reactions would still occur but at rates so slow they would be imperceptible.
symptoms
-subjective indication of disease-effects of a disease experienced by the patient-pain, nausea, malaise
strepto
short chain of prokaryotes
Pay-off phase of glycolysis
(steps 6-10)
intermediates
produced as the starting compound
viremia
viruses circulating in the blood
bacterial cystits
causative agent: E.colipathogenesis: organisms reach bladder by ascending from urethra, bacteria attatch to receptors on bladder lining
Pathogen
organism/virus capable of causing disease
Aerobic Respiration
-uses 2 different NADH dehydrogenases1.proton pump2.?-one form functions optimally only in high O2 conditions and results in the expulsion of 4 protons. The other results in the ejection of only 2 protons, but can more effectively scavenge O2 and thus is particularly useful when the supply of O2 is limited.
sulfate reducers
-group of obligate anaerobes-use sulfate as a terminal electron acceptor, producing hydrogen sulfide as an end product.
chemoorganotrophs
obtain energy by degrading organic compounds such as glucose, releasing the energy of their chemical bonds; ultimately depend on solar energy harvested by photosynthetic organisms because this is what is used to power the synthesis of glucose
oxidation
the removal of a hydrogen atom
Chemiosmotic Theory
-Peter Mitchell, 1961-mechanism by which ATP synthesis is linked to electron transport
_______ generated in catabolism is used in anabolism.
ATP
Catabolism
*opposite of anabolism. breaks down molecules to store energy.encompasses processes that harvest energy released during the disassembly or breakdown of compounds such as glucose using that energy to synthesize ATP
Exotoxin
among most potent toxins known, secreted by bacterium or leak into surrounding fluids following cell lysis-made of protein-groups: neurotoxins, enterotoxins, and cytotoxins
Arcaea
demonstrate a number of same attributes as bacteria, rigid cell wall without PTG, grow in all environments (especially extreme ones and high concentration of salt)
Latent infection
infection never completely eliminated; becomes reactivated and symptomatic
infusion
liquid that contains nutrients which support the growth of microorganisms
secondary infection
additional infection resulting from primary infection
quorum sensing
communication between bacteria by means of small molecules, permitting the bacteria to sense when there is an adequate quorum or number of organisms present to activate certain genes
parasitism
association in which parasite derives benefit at expense of hostpathogen=parasite
protein
composed of numerous combinations of 20 amino acids
respiration
uses the reducing power accumulated in glycolysis, the transition step and the TCA cycle to generate ATP by oxidative phosphorylation*Proces that involves transfer of electrons stripped from a chemical energy source to an electron transport chain, generating a proton motive force that is then used to synthesize ATP.
any essential compounds that a cell cannot synthesize from the appropriate precursor metabolite must be provided from an externl source
anaerobic respiration
similar to aerobic respiration but uses a molecule other than O2 as a terminal electron acceptor
non-competitive, non reversible inhibitors
damage an enzyme permanently
hydrogenation
a reduction reaction in which an electron and an accompanying proton are added
exergonic
if the starting compounds have more energy than the final compounds
Flavorproteins
proteins to which an organic molecule called a flavin is attached ex: FAD
Proton Ejection
-some electron carriers on accept hydrogen atoms, while some only accept electrons-protons are pumped from one side of the membrane to the other, establishing a concentration gradient across the membrane
Cytochromes
proteins that contain heme, a chemical structure that holds an iron atom in the center EX: cytochrome c
activation energy
taken to initiate chemical reaction *by lowering the activation energy barrier, enzymes allow chemicals to undergo rearrangements
Mitochondria
-have 4 different protin complexes, 3 of which function as proton pumps (complexes I, III, IV)-2 electron carriers (coenzyme Q and cytochrome c) shuttle electrons between the complexes
Endospores
a kind of resting bacterial cell highly resistant to heat, radiation and disinfectants
ionic bonds
join charged atoms termed ions together
Gram stain
most widely used procedure for staining bacteria, G+(stained purple) and G-(stained red or pink)
Mutualism
1. Association in which both partners benefit2. bacteria/large intestine (colon)
nucleic acid
a macromolecule consisting of chains of nucleotide subunits to form either DNA or RNA the two types of nucleic acid
Prokaryotes
cell characterized by lack of a nuclear membrane and the absence of membrane-bound organelles
Viroids
simpler than viruses, consist of a single short piece of RNA, smaller than viruses, generally cause plant diseases
Incubation period
time interval between introduction of organism to susceptible host and onset
A-B toxin
A subunit=toxic or active partB subunit=binding part that binds to specific host cell receptors
Endotoxin
LPS of gram- cell wall-heat stable -toxin responsible for septic shock
Molecular postulates
1. virulence factor2. introduction of cloned virulence gene should change non-pathogenic strain to pathogenic strain3. Virulence gene must be expressed during disease4. antibodies and immune cells against virulence gene should be protective
for every glucose molecule degraded, the steps of glyocolysis produce
-ATP-Reducing power-Precursor metabolites
endergonic
if the ending product has more free energy than the starting compounds
non-competitive inhibition
occurs when the inhibitor and the substrate act at different sites to the enzyme(allosteric inhibitor)
central metabolic pathways
*used to gradually oxidize glucose, the preferred energy source of many cells, completely to carbon dioxide-glycolysis-pentose phosphate pathway-tricarboxylic acid cycle (TCA cycle)
Substrate-level phosphorylation
uses the chemical energy released in an exergonic reaction to add Pi to ADP
phosphate groups of ATP
-arranged in tandem-negative charges repel each other-bonds that join them are unstable-they are high energy phosphate bonds (~) - high amount of free energy released when the bonds between the phosphate groups are hydrolyzed
pentose phosphate pathway
*breaks down glucose*primary role in metabolism is the production of compounds used in biosynthesis
Photosynthetic
*synthesis of ATP using the energy of a proton motive force created by harvesting radiant energy.*organisms harvest the energy of sunlight using it to power the synthesis of organic compounds such as glucose (convert the kinetic energy of photons to the potential energy of chemical bonds)
electron transport chain
generates proton motive force-group of membrane-embedded electron carriers that pass electrons sequentially from one to another-Found in the cytoplasmic membrane (prokaryotes) and the inner membrane of the mitochondria (eukaryotes)
anabolism or biosynthesis
*using energy to synthesize bigger molecules. also known as biosynthesis. opposite of catabolism*includes processes that utilize energy stored in ATP to synthesize and assemble subunits of macromolecules that make up the cell including amino acids, nucleotides, and lipids.
Potential Energy
stored energy;can be stored in various forms including chemical bonds, a rock on a hill or water behind a dam
What are polysaccharides, oligosaccharides, and monosaccharides?
polysaccharide-large molecules made of carbohydrate moleculesoligosaccharide-short chains of carbsmonosaccharide-single carbohydrate molecule
What do proteins do?
catalyze reactions, moving cells, taking nutrients into the cell, turning genes on and off, part of the cell membrane
peptide bond
a covalent bond formed between the -COOH group of one amino acid and the -NH2 group of another amino acid
genetic engineering
introduce genes of one organism into an unrelated organism to confer few properties on the organism
systemic infection
or generalized, agent has spread or disseminated throughout the body
adenosine diphosphate (ADP)
*viewed as an acceptor of free energy.*an input of energy is required to add an inorganic phophate group (Pi) to ADP, forming ATP; energy is released when that group is removed from ATP, yielding ADP
E. Coli
can make all of their cell components including proteins, lipids, carbohydrates, and nucleic acids only using a dozen or so precursor metabolited
2 processes used by chemoorganotrophs to provide the energy necessary to form the high-energy phosphate bond
Substrate-level phosphorylation & oxidative phosphorylation
TCA (Tricarboxylic Acid) Cycle
-8 steps-completes the oxidation of glucose-generate ATP, reduce power, form 2 more precursor metabolites
competitive inhibition
the inhibitor binds to the active site of the enzyme, obstructing access of the substrate to that site(sulfanilamide)
allosteric enzymes/allosteric site
when a regulatory molecule binds, the shape of the enzyme changes*alters the relative chemical attaraction of the enzyme for its substrate
adenosine triphosphate (ATP)
*the energy currency of a cell*serves as the ready and immediate donor of free energy*cells constantly turn over ATP*composed of the sugar ribose, the nitrogenous base adenine and three phosphate groups
What are common basic dyes?
Methylene blue, crystal violet, safranin, malachite green
What are compound lipids?
they contain fatty acids, glycerol, and other elements, phospholipid most important compound
What are differential stains?
used to distinguish one bacterial group from another, uses a series of reagents, gram stain & acid-fast stain
pathogenicity island
stretches of DNA in bacteria that code for virulence factors, can be transferred to another bacterium
Phases of the 10-step pathway of glycolysis
-invetment or preparatory phase-pay-off phase
NAD+ & NADP+
can each carry a hydride ion, which consists of 2 electrons and one proton
Components of Electron Transport Chain of Mitochondria
Complex IComplex IICoenzyme QComplex IIICytochrome cComplex IV
Proton Motive Force
the form of energy that results from the electrochemical gradient established as protons are expelled from the cell
oxidation-reduction reaction (redox reaction)
one or more electrons are transferred from one substance to another
How do you prevent leptospirosis?
avoid animal urine, maintain general sanitary conditions in care of animals
TCA (Tricarboxylic Acid) Cycle STEP 2
citrate is chemically rearranged to form a structural isomer, isocitrate
Complex I (electron transport chain of mitochondria)
-also called NADH dehydrogenase complex-accepts electrons from NADH, ultimately transferring them to coenzyme Q; in the process, 4 protons are pumped across the membrane
TCA (Tricarboxylic Acid) Cycle STEP 8
Malate is oxidized to form oxaloacetate; note that oxaloacetate is the starting compound to which acetyl-CoA is added to initiate the cycle. Furing the oxidation, NAD+ is reduced to form NADH + H+
Complex IV (electron transport chain of mitochondria)
-also called cytochrome c oxidase complex-accepts electrons from cytochrome c, ultimately transferring them to oxygen (O2) forming H2O. In the process, 2 protons are pumped across the membrane. -is a terminal oxidoreductase, meaning that it transfers the electrons to the terminal electron acceptor, which, in this case is O2
Electron Transport Chains of Prokaryotes
-a single species may have several alternative carriers so that the system as a whole can function optimally under changeable growth conditions
Reducing power (yield of the transition step)
the transition step, which occurs twice for every molecule of clucose that enters glycolysis, oxidizes pyruvate. This reuces 2 NAD+ to form 2 NADH + 2H+
How do normal flora protect against harmful pathogens?
Normal flora competitively exclude pathogens through:-covering binding sites-consuming available nutrients-producing toxic compounds
TCA (Tricarboxylic Acid) Cycle STEP 1
begins when CoA transfers its acetyle group to 4-carbon compound oxaloacetate, thereby forming the 6-carbon compound citrate
TCA (Tricarboxylic Acid) Cycle STEP 3
Isocitrate is oxidized and a molecule of CO2 is removed, forming the 5-carbon compound alpha-ketoglutarate. During the oxidation, NAD+ is reduced to form NADH + H+
Precursor metabolites - Yield of the TCA cycle
two precursor metabolites used by E.coli are formed as a result of steps 3 & 8
What is the epidemiology of Leptospirosis?
infects numerous species of wild and domestic animals, organism is excreted in urine, swimming in contaminated water accounts for a number of cases
What are the bonding properties of water?
hydrogen bonding produces a polar molecule, polar nature accounts for ability to dissolve numerous compounds,
Reducing Power (yield of pentose phosphate pathway)
a variable amount of reducing power in the form of NADPH is produced
What is the protective role of normal flora?
1. Protection2. Stimulation of the immune system-if normal flora are killed or growth supporessed, pathogens may colonize
What are lipids, and why are they important?
they are critical component of the cell membrane, they are made up of different subunits, they are insoluble in water, smallest of the four macromolecules
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