Chapter 1-7: Energetics and Enzyme Function

Vocabulary flashcards covering thermodynamic principles, free energy changes, ATP function, and enzyme kinetics based on the lecture material.

Energy

The capacity to cause some sort of change, such as creating movement or bonding molecules together.

Entropy

The disorder or spreading out of components within a system.

Gibbs Free Energy

The energy in a system available to do work, represented by the variable $G$.

Delta G ($\Delta G$)

The change in free energy in a reaction, calculated as final free energy minus initial free energy ($G_{\text{final}} - G_{\text{initial}}$).

Exergonic Reaction

A reaction that results in a net loss of free energy from the system, featuring a negative $\Delta G$, an increase in entropy, and occurring spontaneously.

Endergonic Reaction

A non-spontaneous reaction that requires an input of energy to occur, resulting in a positive $\Delta G$, an increase in molecular order, and a decrease in entropy.

ATP (Adenosine Triphosphate)

A renewable energy storage molecule in cells that functions like a rechargeable battery, formed by attaching an inorganic phosphate group to ADP.

Enzyme

An organic molecule, usually a protein or sometimes an RNA molecule, that speeds up chemical reactions and makes them more efficient without being consumed in the process.

Activation Energy

The initial energy barrier or speed bump required to get a chemical reaction started, which is lowered by the presence of an enzyme.

Substrate

A specific reactant molecule that binds to an enzyme during an enzymatic reaction.

Active Site

The specific cleft or divot on an enzyme where the substrate sits and binds to undergo a chemical transformation.

Enzyme-Substrate Complex

The temporary complex formed when a substrate is bound to the active site of an enzyme.

Induced Fit

The subtle shape change of an enzyme's active site upon substrate binding to wrap tightly around the substrate.

Point of Saturation

The stage in an enzymatic reaction where all available enzyme active sites are currently bound to substrates, meaning reaction speed can only increase by adding more enzymes.