Metabolism Flashcards
Metabolism
all the chemical reactions in an organism
Anabolic
Build up
Catabolic
Break down
Energy
capacity to cause change
Kinetic energy
energy associated with motion
Thermal energy
kinetic energy associated with random movements of atoms or molecules
Heat
thermal energy in transfer from one object to another
Potential energy
energy that matter possesses because of its location or structure
Chemical energy
potential energy available in chemical reactions
1st law of thermodynamics
energy cannot be created or destroyed (conservation of energy)
2nd law of thermodynamics
As energy gets transferred around, things go form ordered to disordered, nothing is 100% efficient (disorder always increases)
Entropy
disorder, randomness
organism create…
in this process…
organism create ordered products but the universe continuous to become more disordered. In the process of making ordered products, disordered by-products are released.
gibbs free energy
energy to do work, energy in a system available to work
change in G = G final - G initial
change in G is positive…
final change in energy state has more energy, energy put in during the process
change in G is negative
energy is lost to the environment could do work elsewhere, disorder higher in final state
spontaneous
energetically favorable, not necessarily fast. can occur (slowly) as long as change in G is negative
maximum stability =
equilibrium (a system at equilibrium does no work) a process can only proceed spontaneously if it is moving towards equilibrium
Exergonic reaction
energy released (exit), spontaneously (change in G is NEGATIVE)
Endergonic reaction
energy required, non spontaneous (change in G is POSITIVE)
3 kinds of work
chemical: build up molecules
transport: active transport
mechanical: microtubule movement or muscle contraction
Energy coupling
using an exergonic process to drive an endergonic one
Phosphorylation
transferring a phosphate group
Enzymes
- speed up chemical reactions by lowering the activation energy
- do not participate in the reaction itself
- are not modified by the reaction
activation energy
energy required to get the reaction to proceed, enzymes LOWER the activation energy, allowing the reaction to proceed faster
Active Site can lower activation energy by…
- orienting substrates correctly
- straining substrate bonds
- providing a favorable microenvironment
- covalently bonding to the substrate
Effects on enzymes
- temperature
- pH
- cofactors (inorganic)
- coenzymes (organic)
Competitive Inhibition
active site filled by a mimic normal substance cant gain access –> compete with normal substance
Noncompetitive Inhibition
bind to a different part of the enzyme, cause enough of a change that active site isn’t accessible to normal substrate
Allosteric regulation
protein function/stability by binding of a regulatory molecule on a separate site. “inhibitor” molecule binds on inactive from, stabilizes it
Allosteric Activation
“activator” or regulatory molecule binds on active from and stabilizes it, now open for business basically
Cooperativity
when actual substrate binding influences further binding in other active sites
Feedback inhibition
product turns off process, tells system you have made enough, you can stop now
