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| 9279415066 | disulfide bond | thiol group of Cys can be deprotonted and can occasionally undergo oxidation with another thiol group | 0 | |
| 9279417681 | condensation reaction | reaction in which a water molecule is eliminated | 1 | |
| 9279420543 | peptide bond | amide bond linking the two amino acids | 2 | |
| 9279427991 | residues | remaining portions of amino acids | 3 | |
| 9279432383 | microenvironment | side chain's immediate neighbors, can alter polarity and tendency to lose or accept a proton | 4 | |
| 9279437184 | primary structure | sequence of amino acids in a polypeptide, seldom assumes linear extended conformation | 5 | |
| 9279440122 | secondary structure | local folding arrangement of the polypeptide backbone, exclusive of the side chains, electrons are somewhat delocalized/two resonance forms, partial double bond character therefore no rotation around the CN bond | 6 | |
| 9279447478 | a helix | exhibits a twisted backbone formation polypeptide backbone twists in a right handed helix carbonyl oxygen of each residue forms a hydrogen bond with the backbone NH group four residues ahead atoms of backbone are in Van der Waals contact | 7 | |
| 9279489261 | b sheet | multiple polypeptide strands strands can be arranged in two ways parallel b sheet: neighboring chains run in same direction antiparallel b sheet: neighboring chains run in opposite directions | 8 | |
| 9279495132 | irregular secondary structures | polypeptide does not adopt a defined secondary structure in which successive residues have the same backbone conformation | 9 | |
| 9279500689 | tertiary structure | three dimensional shape of the protein, includes its irregular and regular secondary shape and spatial arrangement of all its side chains | 10 | |
| 9279505564 | domain | polypeptide segment that has folded into a single structural unit with a hydrophobic core 1. core of domain is usually richer in regular secondary structure 2. irregular secondary structures are found in the surface | 11 | |
| 9279720907 | ion pair | when two charged residues of opposite charges interact electrostatically | 12 | |
| 9279726682 | hydrogen bonding | helps fine tune the folded formation folded conformation stabilized by the hydrophobic effect | 13 | |
| 9279734682 | molecular chaperones | certain small proteins require assistance of proteins | 14 | |
| 9279738017 | processing | additional steps beyond polypeptide folding | 15 | |
| 9279742429 | intrinsically unstructured proteins | highly flexible extended segments rich in hydrophobic amino acids | 16 | |
| 9279755390 | quaternary structure | spatial arrangement of all chains subunits: individual polypeptide chains | 17 | |
| 9279759805 | heme | polypeptide chain plus the iron containing porphyrin derivative | 18 | |
| 9279767658 | prosthetic group | an organic compound that allows a protein to carry out some function that the polypeptide alone cannot perform | 19 | |
| 9279778409 | Y (fractional saturation) | proportion of the total myoglobin molecules that have bound O2 | 20 | |
| 9279781728 | saturation | when all the molecules have bund O2 | 21 | |
| 9279783672 | hemoglobin | heterotetramer containing two alpha chains and two beta chains | 22 | |
| 9280845257 | cooperative binding | hb's four heme groups are not independent but communicate with each other in order to work in a unified fashion | 23 | |
| 9280851521 | deoxyhemoglobin | hb without any bound O2 | 24 | |
| 9280855033 | oxyhemoglobin | hb with bound O2 the Fe moves into the center of the porphyrin plane | 25 | |
| 9280859288 | Tense | deoxyhemogobin, reluctant to bind to oxygen because Fe atom lies outside the heme plane | 26 | |
| 9280860717 | Relaxed | oxyhemoglobin, much more oxygen binding | 27 | |
| 9280865410 | allosteric proteins | proteins with multiple binding sites where the binding of a small molecule (ligand) to one site alters the ligand binding affinity for the other sites | 28 | |
| 9280871556 | Bohr Effect | reduction of hb's oxygen binding affinity when the pH decreases increasing pH=more O2 binding | 29 | |
| 9280967657 | BPG | binds in the central cavity of tense hb, the presence of this stabilizes the deoxy conformation of hemoglobin and helps hb let go of oxygen | 30 | |
| 9280972765 | microfilaments | actin filaments, support the plasma membrane and determine cell shape f-actin: polymerized actin g-actin: globular monomeric form | 31 | |
| 9280982173 | treamilling | net rate of addition of subunits to one end of a microfilament that matches the net rate of removal of subunits at the other end | 32 | |
| 9280985531 | intermediate filaments | diameter of 100A, example keratin, exclusively structural proteins and are intermediate in thickness b/w the microtubules and the microfilaments | 33 | |
| 9280991306 | microtubules | diameter of about 240A, cytoskeletal fibers built from small globular protein subunits, thin and flexible rod ex. tubulin construct cilia and flagella and align and separate pairs of chromosomes during mitosis | 34 | |
| 9281000056 | protofilament | assembly of a microtubule that begins with the end to end association of tubulin dimers to form a short linear *blank* | 35 | |
| 9281007136 | coiled coil | basic structural unit of an intermediate filament, dimer of helices that wind around each other ex. keratin | 36 | |
| 9281019972 | hydrolysis | cleavage by water (breaks down peptide bonds) | 37 | |
| 9281024407 | transition state | point of highest energy, considered an intermediate between reactants and products | 38 | |
| 9281026300 | oxidoreductases | oxidation reduction reactions | 39 | |
| 9281026302 | transferases | transfer of functional groups | 40 | |
| 9281028089 | hydrolases | hydrolysis reactinos | 41 | |
| 9281028090 | lyases | group elimination to form double bonds | 42 | |
| 9281030026 | isomerases | isomerization reactions | 43 | |
| 9281030027 | ligases | bond formation coupled with ATP hydrolysis | 44 | |
| 9281032834 | -Delta G | reaction is spontaneous and thermodynamically favorable but the height of the DG determines how fast reaction actually occurs | 45 | |
| 9281036187 | +Delta G | reaction is nonspontaneous and reaction goes uphill | 46 | |
| 9281038806 | catalyst | decreases the activation barrier (DG) | 47 | |
| 9281043275 | cofactor | participates in catalysis when the amino acid side chains of an enzyme cannot provide required catalytic groups | 48 | |
| 9281049762 | coenzymes | organic molecules that may be derived from vitamins | 49 | |
| 9281079359 | cosubstrates | form of coenzyme, enter and exit the active site as substrates do | 50 | |
| 9281081869 | prosthetic group | a tightly bound coenzyme that remains in the active site between reactions | 51 | |
| 9281089888 | acid base catalysis | proton is transferred between the enzyme and a substrate usually to reduce unfavorable character of the transition state, catalytic activity of these are sensitive to changes in pH | 52 | |
| 9281097891 | covalent catalysis | second major chemical reaction mechanism used by enzymes,bond forms between catalyst and substrate during formation of the transition state | 53 | |
| 9281103450 | metal ion catalysis | occurs when metal ions participate in enzymatic reactions by mediating oxidation-reduction reactions or by promoting the reactivity of other groups in the enzyme's active site through electrostatic effects | 54 | |
| 9281122895 | lock and key | model that suggests the catalytic residues must be precisely aligned in the active site so a certain amount of surrounding structure is required to hold them in place | 55 | |
| 9281128507 | transition state stabilization | because the transition state is complementary in shape and charge with the active site getting to transition state increases stability | 56 | |
| 9281133136 | close proximity | increases reaction rates by increasing the frequency of collisions that can lead to a reaction | 57 | |
| 9281135789 | induced fit | upon binding substrates some enzymes undergo a pronounced conformational change so that they almost fully enclose the substrate | 58 | |
| 9281147072 | multisubstrate reactions | biochemical reactions that involve more than one substrate, either oxidation reduction reaction or transferase reactions | 59 | |
| 9281150791 | random mechanism | substrates can bind in any order as long as they both end up in the active site at the same time | 60 | |
| 9281152892 | ordered mechanism | enzymes in which one substrate must bind before the other follow | 61 | |
| 9281155239 | ping pong mechanism | one substrate binds and one product is released before the other substrate binds and the second product is released | 62 | |
| 9281157769 | multistep reactions | each step of this process has characteristic forward and reverse rate constants | 63 | |
| 9281162604 | nonhyperbolic reactions | enzymes that do not obey MM rate equation | 64 | |
| 9281162605 | allosteric enzyme | in *blank* the presence of a substrate at one active site can affect the catalytic activity of the other active sites | 65 | |
| 9281172220 | cooperative behavior | occurs when the enzyme subunits are structurally linked to each other so thata substrate-induced conformational change in one subunit eliicts conformational changes in the remaining subunits | 66 | |
| 9281187965 | irreversible | any reagent that covalently modifies an amino acid side chain in a protein is potentially this | 67 | |
| 9281193201 | suicide substrates | type of irreversible compound, enter enzyme's active site and begin to react, just as a normal substrate would but are unable to undergo the complete reaction and become stuck in the active site | 68 | |
| 9281223394 | competitive inhibition | ost common form of reversible inhibition, it is where the inhibitor is a substance that directly competes with a substrate for binding to the enzyme's active site | 69 | |
| 9281234043 | product inhibition | product of a reaction occupies the enzyme's active site thereby preventing the binding of additional substrate molecules | 70 | |
| 9281288526 | noncompetitive inhibition | inhibitor binds to a site on the enzyme other than the active site and elicits a conformational change that affects the structure or chemical properties of the active site | 71 | |
| 9281324477 | mixed inhibition | inhibitor affects substrate binding so the KM appears to increase or decrease, the inhibitor binding to the enzyme alters its conformation in such a way that both the Vmax and Km are affected although not necessarily in the same way | 72 | |
| 9281329362 | uncompetitive inhibition | multisubstrate reaction where an inhibitor can bind to the enzyme after one substrate has bound in a way that prevents the reaction from continuing and yielding product | 73 | |
| 9281342562 | feedback inhibitor | when concentration in the cell is sufficiently high it shuts down its own synthesis by blocking an earlier step in its biosynthetic pathway | 74 | |
| 9282780504 | competitive inhibitor |  | 75 | |
| 9282788703 | noncompetitive inhibitor |  | 76 | |
| 9282804222 | uncompetitive inhibitor |  | 77 | |
| 9282807942 | competitive inhibitor |  | 78 | |
| 9282809514 | noncompetitive inhibitor |  | 79 | |
| 9282814227 | 80 |
