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Enzyme kinetics Vinicio Gonzalez Perez

Enzyme kinetics Vinicio Gonzalez Perez. Enzymes. Organic Catalysts HUGE variety of substrates Conserved Take one (or more substrates) and give a product. Today. Examples of enzymes. Write coupled differential equation systems. Solve using approximations.

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Enzyme kinetics Vinicio Gonzalez Perez

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  1. Enzyme kinetics Vinicio Gonzalez Perez

  2. Enzymes Organic Catalysts HUGE variety of substrates Conserved Take one (or more substrates) and give a product

  3. Today Examples of enzymes. Write coupled differential equation systems. Solve using approximations. Examine solutions for different systems.

  4. Carbon dioxide – Bicarbonate kinetics Carbonic acid Bicarbonate/CO2 ratio depends on pH Carbonic acid buffer system Protects against sudden changes in pH Simplified kinetics: Half life of carbon dioxide in water ~ 10's sec Effective rate constants

  5. Carbonic Anhydrase Turnover rate kcat~ 5 x10^(5) s^(-1) Michaelis const. Km~ 2x10^(-2)M Abundant, but highly variable Located in red blood cells Located at the stroma of plants Appears everywhere in nature!! CA beta Catalyses the interconversion 10000-100000 times faster!

  6. Solving without integration of the system Useful approximations Substrate, enzyme and product Are we missing something?

  7. Equilibrium approximation The substrate is in instantaneous equilibrium with the complex The total amount of enzyme is conserved When is this approx valid?

  8. Equilibrium approx Reaction speed depends on E and K

  9. Quasi-Steady-State approximation The complex has reached steady state, hence its time derivative is zero The total amount of enzyme is conserved Michaelis-Menten law (blackboard)

  10. Inhibition

  11. Cooperativity

  12. Reaction speeds Quasi-steady-state (coop)

  13. Next session Reversible kinetics Hill model Thermodynamics of reactions Silly examples

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