BIOLOGY 2A03 Lecture Notes - Lecture 2: V12 Engine, Activation Energy, Chemical Equilibrium
22 Feb 2018
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Document Summary
Biological systems, energy can be placed into several categories. Aid in transfer of energy between forms in biological processes. Metabolism = sum of all chemical reactions in cell. Hydrolysis (a-b + h2o (cid:1372) a-oh + h-b) - opp. Phosphorylation/dephosphorylation (adp + pi (cid:1372) atp + h2o) Principles of chemical equilibrium dictate directions of reversible reactions and final conc. Rates of chemical reactions are dependent on activation energy (and temp. reactant/product conc. ) Activation energy, ea = energy needed to pass through transition state. Enzymes = catalysts that inc. rate of reactions by reducing ea. Specific to substrate - often catalyze forward and reverse reactions. Km is [s] at which v = 1/2 vmax. For some enzymes, rates of reactions can also be regulated by: Competitive inhibition - modulator molecule competes with substrate for binding at the active site. Allosteric modulation - modulator binds to regulatory site far from active site, preventing binding of substrate to active site.
