Intro to Metabolism

Vocabulary flashcards related to enzyme function and metabolic processes.

Exergonic Reactions

have a net release of free energy, and can be spontaneous. They do not require energy input over the transition state.

Endergonic Reactions

Reactions that require large amounts of energy.

Metabolism

The total of chemical processes that occur in living organisms, including growth and waste elimination.

Catabolic Processes

Metabolic processes that release energy by breaking down molecules. exergonic

Anabolic Processes

Metabolic processes that consume energy to build molecules. endergonic

Enzymes

Organic molecules that reduce the activation energy (Ea) and speed up reactions. They are specific and regulated, and no catalyst affects them.

Active Site

The specific region of an enzyme where substrate binding and catalysis occur.

Cofactors

Non-protein enzyme helpers.

Apoenzyme

The protein portion of an enzyme.

Holoenzyme

The complete enzyme consisting of an apoenzyme plus a cofactor.

Enzyme Kinetics

The study of the rates of enzyme-catalyzed reactions.

Michaelis-Menten Kinetics

A rate equation (Vo = Vmax [S] / (Km + [S])) for a single-substrate enzyme-catalyzed reaction.

Km

Substrate concentration at which the reaction rate is half of Vmax. Km = (k-1 + k2) / k1

Vmax

The maximum rate of an enzyme-catalyzed reaction when the enzyme is saturated with substrate.

Competitive Inhibitors

Reversible inhibitors that bind to the active site, increasing Km but not affecting Vmax.

Non-competitive Inhibitors

Reversible inhibitors that do not bind to the active site, decreasing Vmax but not affecting Km. They change the shape of the enzyme.

Allosteric Regulation

Regulation of enzyme activity by activators or inhibitors that bind to a site other than the active site.

Cooperativity

Amplification of enzyme activity through changes in shape. Can occur in polypeptide subunits.

Feedback Inhibition

A metabolic pathway regulation where the end product shuts down the pathway, preventing wasted resources.