20751050
Descrição
FlashCards por Marissa Alvarez, atualizado more than 1 year ago
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Criado por Marissa Alvarez
quase 5 anos atrás
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| Questão | Responda |
| Concepts to understand | Rate of reaction, rate constant, order of reaction Reaction can be reversible Rate constants for forward and reverse reactions are not the same Equilibrium constant Keq Laws of Thermodynamics • Enthalpy, Entropy, Gibbs free energy (G) • If ΔG < 0, the forward reaction is favorable Transition state and activation energy |
| Definition of kinetics 1 a: a branch of science that deals with the effects of forces upon the motions of material bodies or with changes in a physical or chemical system b: the rate of ___ in such a system 2: the mechanism by which a physical or chemical change is effected Chemical kinetics studies reaction ___: -->Mathematical description based on the reaction model -->What affects the rates: T, pH, enzymes, spatial restrictions, ... | change rates |
| Zero Reaction The biochemical reaction may be of zero-order when enzyme-catalyzed max This happens when the enzyme (E) is saturated by the substrate (S). Concentration of S exceeds that of E [S] >> [E} | |
| Mon-molecular FIRST ORDER Reaction A --> B (can be reversible) k = rate (depends on multiple factors such as temperature) rate = ___ reaction rate units = ___ 1 st order reaction: Biochemical reaction may be of 1st order when enzyme-catalyzed If this case [S] __ [E]. | M/s k[A] << |
| Second-Order bimolecular reaction A + B --> C + D rate or V = ____ | k[A][B] |
| Second-Order bimolecular reaction & Equilibrium Concept Equilibrium when: forward rate = ___ rate k1[A][B] = k-1[C][D] The ratio of product to reactant concentrations is constant: Keq = concentration of products / concentration of reactants (k1 / k-1) so it would look like: ____ / ____ when keq >> 1 then rxn strongly favors ___ when keq << 1 then rxn strongly favors ____ |
reverse
Keq = ([C][D]) / ([A][B])
products
reactants
Image:
Rates (binary/octet-stream)
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| Thermodynamics is the flow of __ 0th Law of thermodynamics = states that if two thermodynamic systems are each in thermal equilibrium with a third one, then they are in thermal equilibrium with ___ ___ | heat each other |
| First Law of Thermodynamics = The law of Conversation of Energy The total amount of energy in the Universe remains Energy is neither created nor destroyed, it just ___ its form • Conservation of mass in chemistry is a special case of the law, assuming no nuclear reactions occur. | constant changes |
| 2nd Law of Thermodynamics Multiple equivalent definitions have been proposed by scientists: -Heat does not transfer from cold systems to hot systems • No work can be done at a ___ temperature • Total amount of entropy (S) of the universe always ____ What is Entropy? defined as a measure of the system ____ | constant increases disorder |
| 3rd Law of Thermodynamics If an object reaches the absolute zero temperature (0K = -273.15 degrees C = -459.67 degrees F), its atoms will stop moving. T(K) = T(C) + ___ | 273.15 |
| Gibbs free energy G = __ - __ H — enthalpy, a heat function at constant pressure (p=const.) Since most of the biochemical reactions are isobaric, ΔH = ΔHeat S — Entropy T — Temperature (K) ΔH < 0 = rxn is ___ ΔH > 0 = rxn is ___ | G = H-TS exothermic endothermic |
| G = H-TS Reaction will proceed forward if G is reduced ΔG __ 0 If ΔG < 0 then ΔH -TΔS must be __ 0 A non-spontaneous rxn can still proceed if ___ to another reaction providing that overall ΔG < 0 (the reaction can be entropy driven) | < < coupled |
| Reaction will proceed until it reaches ___ If ΔG = 0 Then ΔH = TΔS | equilibrium |
| If the transition state has higher energy compared to the reactants, additional activation energy, Ea, is required -Need to __ the activation energy | overcome |
| Two ways to speed up a reaction: 1. Increase ___ (may destroy your reactants) 2. Use ___ (bio-catalysts) Equivalent to: 1. Produces more 'hot' molecules 2. ___ activation energy, 3D coordination, longer time | temperature enzymes Decreases |
| To find Keq: Given a concentration of either the reactant or product | keq = [C]^2 / [A]^2 |
| To find concentrations given Keq: You can find concentration of [A], [B], [C], [D] | 1/ ( 1+sqr(keq) ) = [A} [A] = [B] 1-[A] = [C] [C] = [D] |
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