5 BIO 326R Metabolism 1 - BIO 326R Metabolism 1...

Info iconThis preview shows pages 1–8. Sign up to view the full content.

View Full Document Right Arrow Icon
BIO 326R Metabolism 1
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Thermodynamics Energy can neither be created nor destroyed “You can’t get something for nothing” TNSTAAF Entropy within an isolated system cannot decrease You can decrease entropy within a system if you do work (use energy) on it. This means the system is not isolated and the use of energy will cause increases in entropy elsewhere. Can you name an isolated system? A cell is not an isolated system . As one example DNA replication can represent a decrease in entropy – total entropy in the universe still increases because a lot of heat is generated from dNTP hydrolysis. This heat leaves the cells eventually. Protein and RNA synthesis are similar in this regard. “You can’t break even” One consequence of this is that if a reaction provides energy, you can use that energy to something else – but you can never use 100% of that energy, some of it is lost (usually as heat). Nothing is 100% efficient, there is no perpetual motion machine. ΔG = ΔH - TΔS
Background image of page 2
Free energy (G) Progress of reaction (not necessarily time) ΔG A + B C + D A + B C + D AB
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Chemical Equilibrium Most reactions are reversible The ratio of products to reactants is the equilibrium constant, k eq A + B C + D [A][B] [C][D] k eq =
Background image of page 4
Chemical equlibrium Reactions that proceed to completion (or nearly so) will have a very high k eq High k eq = more products than reactants A very high keq indicates that the reaction is essentially irreversible The equilibrium constant is a reflection of the change in free energy of the reaction, ΔG (“delta G”) A large (negative) change in free energy gives a very high k eq A + B C + D [C][D] >[A][B] [A][B] [C][D] k eq = > 1
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Gibbs Free Energy Working definition – Total energy in the chemical bonds Reactions that proceed spontaneously will have a negative change in free energy (negative delta G) Free energy of reactants is higher than free energy of products A + B C + D Free energy of A and B is higher than free energy of C and D
Background image of page 6
Since the ratio of products to reactants is a constant, the direction of a reaction can be (briefly) controlled or changed by changing the concentration of its components A + B [A][B] [C][D]
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 8
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 04/09/2009 for the course BIO 326R taught by Professor Whiteley during the Spring '08 term at University of Texas at Austin.

Page1 / 21

5 BIO 326R Metabolism 1 - BIO 326R Metabolism 1...

This preview shows document pages 1 - 8. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online