Ap bio

Gibbs Free Energy (G)

Thermodynamic potential for maximum reversible work.

ΔG < 0

Indicates a spontaneous reaction (exergonic).

ΔG > 0

Indicates a non-spontaneous reaction (endergonic).

ΔG equation

ΔG = ΔH - TΔS relates energy changes.

Exergonic reactions

Release energy, resulting in stable products.

Endergonic reactions

Require energy input, yielding unstable products.

Temperature effect

Higher temperature can increase entropy (ΔS).

Le Chatelier's principle

Equilibrium systems adjust concentrations to changes.

ATP hydrolysis

Exergonic reaction that drives endergonic processes.

Activation Energy (EA)

Minimum energy required for a reaction to occur.

Induced fit model

Substrate binding induces enzyme conformational change.

Competitive inhibition

Substrate competes with inhibitor for active site.

Non-competitive inhibition

Inhibitor binds elsewhere, reducing enzyme activity.

Allosteric regulation

Molecules bind non-actively to regulate enzyme function.

pH effect on enzymes

Extreme pH can denature enzymes, altering structure.

Temperature effect on enzymes

Moderate heat enhances activity; extreme heat denatures.

Cofactors

Non-protein molecules required for some enzyme activities.

Feedback inhibition

End product inhibits earlier pathway steps.

Homeostasis in cells

Regulates metabolite concentrations to maintain balance.

Cooperative binding

Substrate binding enhances affinity for additional substrates.

Allosteric activators

Increase enzyme activity through non-active site binding.

Allosteric inhibitors

Decrease enzyme activity via non-active site binding.

Example of feedback inhibition

Isoleucine inhibits threonine deaminase in synthesis.

Hemoglobin cooperative binding

Oxygen binding increases likelihood of further binding.