VCE bio Unit 3 AOS 2 (copy)

Enzymes

Specialized proteins that act as biological catalysts, increasing the rate of chemical reactions within cells without being consumed.

Activation Energy

The minimum energy required to initiate a chemical reaction, which enzymes lower.

Lock-and-Key Model

The theory that a substrate fits precisely into the enzyme’s active site, similar to a key fitting into a lock.

Induced Fit Model

The theory suggesting that the enzyme undergoes a conformational change upon substrate binding, enhancing its fit.

Competitive Inhibition

A type of inhibition where an inhibitor competes with the substrate for binding at the enzyme's active site.

Non-competitive Inhibition

Inhibition that occurs when an inhibitor binds to an allosteric site, altering the enzyme's conformation without competing with the substrate.

Irreversible Inhibition

Inhibition where an inhibitor permanently binds to and modifies the active site of the enzyme.

Biochemical Pathways

A series of enzyme-controlled reactions where the product of one reaction becomes the substrate for the next.

Feedback Inhibition

A regulatory mechanism where an end-product of a metabolic pathway binds to an allosteric site on an early enzyme, reducing its activity.

Coenzymes

Organic non-protein molecules that assist enzymes by carrying electrons, atoms, or functional groups necessary for enzymatic reactions.

ATP

Adenosine triphosphate, the primary energy currency of the cell.

NAD⁺ / NADH

Nicotinamide adenine dinucleotide, an electron carrier that accepts electrons during cellular respiration.

FAD / FADH₂

Flavin adenine dinucleotide, functioning as an electron carrier in the Krebs cycle.

Coenzyme A

Transfers acetyl groups during the metabolism of fatty acids and synthesis of cholesterol.

NADP⁺ / NADPH

Nicotinamide adenine dinucleotide phosphate, mainly utilized in photosynthesis for glucose synthesis.