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162 Cards in this Set
- Front
- Back
adaptation
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evolution through natural selection leading to an organism whose physio, anatomy, and behavior are matched to the demands of its enviro
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acclimatization
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a persisting spectrum of changes due to prolonged exposure to enviromental conditions such as high or low temp.
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acclimation
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a persisting change in a specific funtion due to prolonged exposure to an environmental condition such as high or low temp.
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deoxyribonucleic acid
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the class of nucleic acids resposible for hereditary transmission and for the coding of amino acid sequences of proteins
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mutations
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a heritable alteration in genetic material
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feedback
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the return of ouput to the input part of a system
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negative feedback
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sign of the output is inverted before it is fed back to the input so as to stabilize the output
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set point
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point that system is to be held (homeostasis)
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positive feedback
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error signal is amplified and unchanged, reinforcing the original disturbance (AP, childbird, vomiting)
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disturbance
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change in the state of a controlled system
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signal inversion
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sign or direction of ouput is opposite to that of input
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conformers
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an animal whose internal conditions tend to parallel those of the external enviro
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regulators
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an animal that used biochemical, physiological, behavioral, or other mechs to maintain internal homeostasis.
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solvent
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capable of breaking down molecular constituents
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electromotive force
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(emf) the potenial difference across the terminals of a battery or any other source of electric energy
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electronegativity
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affinity for electrons
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dipole
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a molecule having separate regions of net negative and net positive charge, so that one end acts as a positive pole and the other as a negative pole
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hydrogen bonds
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a weak electrostatic attraction between a hydrogen atom bound to a highly electronegative element in a molecule and another highly electronegative atom in the same or a different molecule
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dielectric constant
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a measure of the degree to which a substance is able to store electric charge under an applied voltage
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solvation
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the clustering of solvent molecules around a solute
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hydration
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solvation when the solvent is water
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amphipathic
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bearing both hydrophylic and hydrophobic groups
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hydrophilic
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having an affinity for water
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hydrophobic
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lacking an affinity for water
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micelle
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a microscopic particle made from an aggregation of amphipathic molecules in solution
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moles
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avogadro's number (6.023 X 10*23) of molecules of an element or compound: equal to the molecular weight in grams
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molality
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the number of moles of solution in a kilogram of a pure solvent
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molarity
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the number of moles of solute in a liter of solution
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osmotic pressure
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the pressure that can potentially be created by osmosis between two solutions separated by a semipermeable membrane; the amount of pressure necessary to prevent osmotic flow between the two solutions
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osmolarity
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the effective osmotic pressure of a solution
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colligative properties
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characteristics of a solution that depend on the number of molecules in a given volume
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activity
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the capacity of a substance to react with another substance; the effective concentration of an ionic species in the free state
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activity coefficient
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a proportionality factor obtained by dividing the effective reactive concentration of an ion (as indicated) by its properties in a solution) by its molar concentration.
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hydronium ion
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(H3O+) a hydrogen ion (H+) cmbined with a water molecule (H2O)
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hydroxyl ion
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OH-
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base
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a proton acceptor
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acid
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a proton donor
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amphoteric
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having opposite characteristics; behaving as either an acid or a base
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pH
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Number of H+ ions in solution
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pN
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the pH of a solution at neutrality
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neutral
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pure water at 25 degrees celsius
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zwitterion
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a molecule carrying both negatively and positively ionized or ionizable sites
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isoelectric point
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pH at which the net charge of molecule is zero
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optimal pH
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at which there is the highest probability of catalysis
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Henderson-Hasselbalch equation
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pH = pK' + log([H+ acceptor]/[H+ donor]) the formula for calculation of the pH of a buffer solution
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coulombs
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(c) a unit of electric charge; equal to the amount of charge transferred in 1 second by 1 ampere (A) of current
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faraday
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a measure of electric charge, -96,487 C X mol-1
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current
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the flow of electric charge. A current of 1 coulomb(C) per second is called an ampere (A). By convention, the direction of current flow is the direction in which a positive charge moves (ie from the anode to the cathode)
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amperes
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(A) a unite of electric current equal to the current produced through a 1 ohm (V) resistance by a potential differeence of 1 volt (V); the movement of 1 coulomb (c) of charge per second
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voltage
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difference in potential
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volts
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(V) a unit of electromotive force; the force required to induce a 1 amp current to flow thru a 1 ohm resistance
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resistance
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(R ) the property that hinders the flow of electric current. The unit of measure is the ohm, defined as the resistance that allows 1 amp of current to flow when a potential drop of 1 volt exists across the resistance
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ohms
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a unit of electrical resistance, equivalent to the resistance of a column of mercury 1mm2 in cross-section and 106 cm long
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ohm's law
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I = V/R; the strength of an electric current, I, varies directly as the voltage, V, and inversely as the resistance, R.
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resistivity
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the resistance of a conductor 1 cm in length and 1 cm2 in cross-sectional area
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conductance
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(electrical)G a measure of the ease with which a conductor carries an electric current; the unit of measure is the siemen (S), reciprocal of the ohm
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siemen
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(S) the unit of electrical conductance; reciprocal of the ohm
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conductivity
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the intrinsic ability of a substance to conduct electric current; the reciprocal of resistivity
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capacitance
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the ability to store electric charge by electrostatic means. The unit of measure for capacitance is the farad (F), which describes the proportionality between charge stored and potential for a given voltage: C = q/V = coulombs per volt.
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farad
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(F) the unit of electrical capacitance
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cathode
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negative electrode or pole to which positively charged ions are attracted
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anode
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a positive electrode or pole to which negatively charged ions are attracted
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electrical mobility
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the rate at which an ionic species megrates in solution
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affinity sequence
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(selectivity sequency) the order of preference with which an electrostatic site will bind different species of counterions
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triglyceride
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a neutral molecule composed of three fatty acid residues esterified to glycerol; formed in animals from carbs
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saturated
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in reference to fatty acid chains, indicates absence of double bonds
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unsaturated
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in reference to fatty acid molecules, having some carbon-carbon double bonds
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phospholipids
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a phosphorus-containing lipid that hydrolyzes to fatty acids, glycerol, and a nitrogenous compound; makes up cell membranes
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lipophilic
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having an affinity for lipids
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carbohydrates
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aldehyde of ketone derivatives of alcohol; utilized by animal cells primarily for the storage and supply of chemical energy; most important are the sugars and starches
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polymer
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a compound composed of a linear sequence of simple molecules or residues
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starch
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a polysaccharide of plant origin (C6H10O5)n
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glycogen
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a highly branced D-glucose polymer found in animals
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peptide bonds
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the center bond of the -C(0)-NH-group, created by the condensation of amino acids into peptides
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peptide
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a molecule consisting of a linear array of amino acid residues. Protein molecules are made of one or more peptides: short peptide chains are called oligopetptides and long chains are polypeptides
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primary structure
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the sequence of amino acid residues of a polypeptide chain
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secondary structure
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the repeating conformation adopted by a polypeptide segment (eg alpha helix)
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teriary structure
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the ways in which a polypeptide chain is folded or bent to produce the overall conformation of the molecule
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quaternary structure
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the characteristic way in which the subunits of a protein containing more than one polypeptide chain are combined
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alpha helix
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helical secondary structure of many porteins in which each NH group is hydrogen-bonded to a CO group at a distance equivalent to three amino acid residues; the helix makes a complete turn for each 3.6 residues
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beta pleated sheet
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a protein secondary structure in which two or more distinct amino acid chains lie side by side, held together by hydrogen bonds
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van der waals forces
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the close-range, relatively weak attraction exhibited between atoms and molecules with hydrophobic properties
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disulfide linkage
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a bond between sulfide groups that determines protein tertiary structure by linking together portions of polypeptide chains
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denaturation
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alteration of destruction of the normal nature of a substance by chemical or physical means
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molecular chaperones
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a family of proteins that features prominently in protein folding and the preservation of the complexly folded state of proteins
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ribonucleic acid
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a nucleic acid made up of adenine, guanine, cytosine, uracil, ribose, and phosphoric acid, responsible for the transcription of DNA and its translation into protein
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nucleic acids
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nucleotide polymers of high molecular weight
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nucleotides
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a component of nucleic acids, made up of a purine or pyrimidine base, a ribose or deoxyribose sugar, and a phosphate group
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triphosphodiester linkages
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in ATP, when broken release energy for enerdergonic reactions
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transcription
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the formation of an RNA chain of a complementary base sequence from the informational base sequence of DNA
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messenger RNA
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(mRNA) a type of RNA that is responsible for transmission of the informational base sequence of DNA to the ribosomes
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metabolism
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the totality of physical and chemical processes in anabolism, catabolism, and cell energetics
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metabolic pathways
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a sequence of enzymatic reactions that changes one substance into another
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energy
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capacity to perform work
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potential energy
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stored energy that can be released to do work
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kinetic energy
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energy inherent in the motion of a mass
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chemical energy
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energy contained in the chemical bonds holding molecules together
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first law of thermodynamics
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the principle that energy is neither created nor lost in any process
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second law of thermodynamics
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the principle that all natural or spontaneous processes are accompanied by an increase in entropy
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entropy
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a measure of that portion of energy not available for work in a closed system; a measure of molecular randomness
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free energy
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the energy available to do work at a given temperature and pressure
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endergonic reaction
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characterized by a concomitant absorption of energy
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exergonic reaction
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characterized by a concomitant release of energy, often accompanied by a release of heat
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adenosine triphosphate (ATP)
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an energy-rich nucleotide used as a common energy currency by all cells
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activation energy
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the energy required to bring reactant molecules to velocities sufficiently high to break or make chemical bonds
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catalyst
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a substance that increases the rate of a reaction without being used up in the reaction
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enzyme
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a protein with catalytic properties
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substrate
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a substance that is acted on by an enzyme
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proteolytic
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protein hydrolyzing
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active site
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the catalylic region of an enzyme molecule
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enzyme activity
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a measure of the catalytic potency of an enzyme: the number of substate molecules that react per minute per enzyme molecule
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turnover number
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a measure of the catalytic potency of an enzyme, usually given as reactions catalyzed per second
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cofactors
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an atom, ions, or molecule tht combines with an enzyme to activate it
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coenzyme
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an organic molecule that combines with an apoenzyme to form a functioning enzyme
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apoenzyme
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the portein portion of an enzyme, which combines with a coenzyme to form a functioning enzyme
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cytosol
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the unstructured aqueous phase of the cytoplasm between the structured organelles
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rate constant
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(specific reaction rate) the proportionality factor by which the concentration of a reactant in an enzymatic reactin is related to the reaction rate
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michaelis Menten equation
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the equation describing the dependence of initial reaction velocity on substrate concentation for catalyzed reactions
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Lineweaver Burk equation
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straight line transformation of the michaelis-menten equation
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competitive inhibition
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reversible inhibition of enzyme activity caused by competition between a substate and an inhibitor for the active site of the enzyme
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noncompetitive inhibition
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enzyme inhibition due to alteration or destruction of the active site
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allosteric site
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an area of an enzyme that binds a substance other than the substrate, changing the conformation of the protein so as to alter the catalytic effectiveness of the active site.
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end product inhibition
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inhibition of a biosynthetic pathway by the end product of the pathway
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anaerobic
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oxygen free
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aerobic
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require a supply of oxygen for cellular respiration
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mitochondria
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membrane-enclosed organelles where APT is produced during aerobic metabolism
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reduction
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the addition of electrons to a substance
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oxidation
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a loss of electrons or an increase in the net positivity of an atom or molecule. Biological oxidations are usually achieved by removal of hydrogen from a molecule
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reductant
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the electron donor in a redox reaction
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oxidant
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the electron acceptor in a redox reaction
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redox pair
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two compounds, molecules, or atoms involved in mutual reduction and oxidation
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reduction potential
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a measurement of the tendency of a reductant to yield electrons in a redox reaction, expressed in volts
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electron pressure
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a measure of the tendency to donate electrons
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plasma membrane
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cell membrane; surface membrane
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lipid bilayer
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the continuous double layer of lipid molecules that forms the basic structure of a biological membrane
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peripheral proteins
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membrane-lined proteins that do not extend thru the membrane
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integral proteins
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proteins spanning the plasma membrane that form selective filters and active transport devices that get nutrients into and cellular products and waste out of the cell
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phosphoglycerides
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glycerol based lipids found in biological membranes
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sphingolipids
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a lipid formed by a fatty acid attached to the nitrogen atom of sphingosine, a long chain, oily amino alcohol; occurs primarily in the membranes of neurons
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sterols
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a group of solid, primarily unsaturated polycyclic alcohols
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fluid mosaic model
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the accepted model for bio membranes, in which globular proteins are integrated into the lipid bilayer
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cholesterol
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a natural sterol, precursor to the steroid hormones
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diffusion
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dispersion of atoms, molecules, or ions as a result of random thermal motion
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fick diffusion equation
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an equation defining the rate of solute diffusion through a solvent
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influx
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the movement of solute or solvent into a cell across the plasma membrane
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efflux
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the movement of solute or solvent out of a cell across the plama membrane
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net flux
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the sum of influx and efflux thru a membrane or other material
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permeability
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the ease with which substances can pass through a membrane
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osmosis
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the movement of pure solvent from an area of low solute concentration to an area of high solute concentation through a semipermeable membrane
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diffusion coefficient
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a coefficient relating the rate of diffusional flux to concentration gradient, path length, and the area across which diffusion occurs
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paritition coefficient
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ratio of the distribution of a substance between two different liquid phases (eg oil and water)
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hydrostatic pressure
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force exerted over an area due to pressure in a fluid
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osmotic pressure
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the pressure that can potentially be created by osmosis between 2 solutions separated by a semipermeable membrane
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osmotic flow
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the solvent flux due to osmotic pressure
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isoosmotic
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having the same osmotic pressure
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hypoosmotic
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containing a lower concentration of osmotically active constituents than the solution of reference
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hyperosmotic
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containing a greater concentration of osmotically active constituents than the solution of reference
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osmolarity
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the effective osmotic pressure of a solution
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hypotonic
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having a lower tonicity than a reference solution
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hypertonic
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having a higher tonicity than a reference solution
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tonicity
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the relative osmotic pressure of a solution under given conditions
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isotonic
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having a tonicity equal to that of a reference solution.
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