Energy and Metabolism

Energy

the capacity to create change

Between two competing events, which one is more likely to occur?

The one that requires the least amount of energy

As particles move or vibrate, using kinetic energy, they…

increase surrounding temperature (thermal energy)

Atoms are constantly vibrating, but the vibrations are reduced when

they are bonded because the bond acts as a coil, taking the vibrations of the atoms

Which type of bonds store energy

Covalent bonds

*thus, the more covalent bonds means the more energy is stored

Potential energy

stored energy

How do chemical reactions form?

By chance encounters of molecules that move randomly in an environment that may or may not have the right amount of energy.

Factors for chemical reactions:

• Collisions - must have enough chemical energy transferred to help start the chemical reaction.

• Position - must collide with their areas of interest exposed and directed towards each other (not common)

• Available substrates - same chemical reactions require the presence of a catalyst, additional electrons or protons, functional groups, etc.

Enzymes

proteins that have pockets inside them where molecules sit in the right position for a reaction to occur.

How do enzymes make reactions more efficient?

They reduce activation energy by providing an environment where the reaction is much more likely to occur.

Phosphate groups

Act as on off switches to control enzymes

Enzymes are

proteins that must maintain their tertiary and/or quaternary structures to do their job.

Adenosine triphosphate (ATP)

• unstable

• 3 phosphate groups (the last requires very little energy to be released)

• releases heat with the third phosphate charged w/ kinetic energy that can be transferred to a nearby reactions.