{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

Biochem6 - ENERGY We need energy to do things such as...

Info iconThis preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon
ENERGY We need energy to do things, such as biosynthesis, work (muscle contraction, etc) •Chemical reactions enzymes and kinetics thermodynamics •Metabolism - getting energy from fuel (food)! The energy “star” is ATP! Figure 6-5 ATP…the “energy molecule” THERMODYNAMICS Thermodynamics tells us what is possible given an infinite amount of time….what will happen at “equilibrium” Some reactions proceed spontaneously “exergonic”; energy is released Some reactions are not spontaneous “endergonic”; energy is required Figure 6-3 Exergonic and endergonic chemical reactions
Background image of page 1

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

View Full Document Right Arrow Icon
What if there is a reaction that we really need……but it is endergonic? Like: AA1 + AA2 --> AA1-AA2 ! G= +4 kcal/mole ATP --> ADP + Pi ! G= -7 kcal/mole AA1 + AA2 + ATP --> AA1-AA2 + ADP + Pi ! G= +3 kcal/mole We can add energy into the reaction…like having a bulldozer push a boulder up a hill! This is a “coupled reaction” Figure 6-7 Coupling of ATP Hydrolysis to an Endergonic Rxn Figure 6-6 Coupling of Chemical Reactions A view of the big picture A more realistic look at chemical reactions Let’s talk about chemical “kinetics” the rates at which reactions occur All related to “activation energy”
Background image of page 2
Figure 6-8 Activation energy initiates reactions The rate at which a reaction proceeds depends upon how big of an activation energy it must overcome So, even if the overall energetics are favorable (i.e., ! G > 0),
Background image of page 3

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

View Full Document Right Arrow Icon
Image of page 4
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}