Topic 4: AP Bio Quiz (Enzyme Quiz)

ATP

The main energy currency of the cell, a molecule storing and supplying energy for most cellular activities like muscle contraction, nerve impulses, and chemical synthesis

Kinetic energy

the energy of motion, essential for understanding how molecules move, react, and transport substances in living systems, such as the rapid movement of molecules causing heat (like in respiration) or the movement driving diffusion and active transport across cell membranes

Potential energy

stored energy in biological systems, primarily from the arrangement of atoms in molecules (like glucose, ATP) or an object's position, ready to be used for work, like powering cell functions or movement, by converting into kinetic energy

Free energy

the energy in a system (like a cell) available to do useful work, determining if a biological reaction happens spontaneously (spontaneity)

Exergonic reaction

a spontaneous chemical process that releases free energy (negative ΔG)

Endergonic reaction

a non-spontaneous chemical process that absorbs energy from its surroundings, requiring a net input of energy to proceed, resulting in products with higher free energy (positive ΔG)

Catabolic pathway

a metabolic process that breaks down complex molecules (like food) into simpler ones, releasing energy

Anabolic pathway

a metabolic process that builds complex molecules from simpler ones, requiring an input of energy (usually ATP), essential for growth, repair, and storing energy, like building proteins from amino acids or synthesizing DNA

Entropy

the measure of disorder, randomness, or energy dispersal in a system

Energy

the capacity to do work or cause change

Activation Energy

the crucial minimum energy barrier reactants must overcome to start a chemical reaction

Laws of Thermodynamics

explain energy flow in living things: the First Law (Energy Conservation) says energy can't be made or destroyed, just changed (e.g., food to ATP/heat); the Second Law (Entropy) says every transfer loses usable energy as heat, increasing overall disorder (entropy), forcing organisms to constantly use energy to stay organized. These laws explain why metabolism isn't 100% efficient and how life maintains order against universal chaos by inputting energy.