Biochemistry and Physiology

1. Biochemistry and Physiology

2. Monomolecular (first order) chemical reaction k A  P A – reactant, P – product, R(t) – reactant concentration C(t) – product concentration k – reaction rate

3. Equations - Exponential decay

4. 50 45 40 35 30 25 20 15 10 5 0 Monomolecular reaction Product C(t)=A(1-exp(-kt)) Concentrations Reactant R(t)=A exp(-kt) 0 1 2 3 4 5 6 7 8 9 10 time

5. Second order reaction k A+B  C+D A,B – reactants (substrates), C,D – products, a(t), b(t) – reactants concentrations c(t), d(t) – product concentrations k – reaction rate

6. Equations – law of mass action

7. Phase portrait Equilibria depend on initial conditions

9. Second order bi-directional reaction k+ A+B C+D k- A,B – reactants (substrates), C,D – products, a(t), b(t) – reactants concentrations c(t), d(t) – product concentrations k+ k- – reaction rates

10. Equations

11. Phase portraits

12. Equilibria

13. Enzyme catalyzed reactions k+ k2 E + S ES E + P k- e(t), s(t) - enzyme and substrate molar concentrations x(t), p(t) – compund (ES) and productmolar concentrations

14. Equations, Michaelis – Menten model

15. Rate of compound concentration change = - rate of free enzyme concentration change

17. k+ E + S ES k- is much faster than k2 ES E + P

19. Michaelis – Menten equation

20. Ligand – receptor interaction model

21. k+ G + R GR k- g(t) – molar concentration of free ligand r(t) - molar concentration of free receptor x(t) – molar concentration of bindings

22. Law of mass action