Cellular Energetics and Enzyme Function

These flashcards cover key vocabulary terms and definitions related to cellular energetics, enzyme function, and photosynthesis.

Enzymes

Special proteins that act as biological catalysts, speeding up chemical reactions by lowering activation energy.

Substrate

The reactant that binds to the enzyme, forming a temporary enzyme-substrate complex.

Product

The end result of an enzyme-catalyzed reaction.

Active Site

The catalytic site of an enzyme where the substrate fits, highly specific to the substrate shape.

Activation Energy (EA)

The minimum energy required to start a chemical reaction.

Lock and Key Model

A simplistic representation of enzyme action where a substrate fits precisely into the enzyme's active site.

Denaturation

The process in which a protein loses its 3-D shape and, consequently, its function, often due to temperature or pH changes.

Cofactors

Non-protein, small inorganic compounds and ions that assist enzymes in catalyzing reactions.

Coenzymes

Non-protein, organic molecules that bind to enzymes and assist in their function, often derived from vitamins.

Competitive Inhibitors

Compounds that block the active site of an enzyme, preventing substrate binding.

Non-Competitive (Allosteric) Inhibitors

Compounds that bind to an enzyme at a site other than the active site, changing the enzyme's shape and inhibiting its function.

Exergonic Reactions

Reactions that proceed with a net release of free energy.

Endergonic Reactions

Reactions that absorb free energy from their surroundings.

ATP (Adenosine Triphosphate)

The primary energy currency of cells, providing energy for various biological processes.

Glycolysis

The metabolic pathway that converts glucose into pyruvic acid, producing ATP and NADH, occurring in the cytoplasm.

Krebs Cycle (Citric Acid Cycle)

A series of reactions that fully oxidizes Acetyl-CoA to CO₂, producing ATP, NADH, and FADH₂.

Electron Transport Chain (ETC)

A series of protein complexes in the inner mitochondrial membrane that transfer electrons and produce ATP.

Chemiosmosis

The process of using a proton gradient to drive ATP synthesis.

Photorespiration

A wasteful pathway that occurs when RuBisCO catalyzes the reaction of RuBP with oxygen instead of carbon dioxide.

Calvin Cycle

A light-independent reaction in photosynthesis that fixes carbon dioxide into glucose using ATP and NADPH.