Biology Lecture Notes on Energy and Metabolism

Flashcards covering key concepts of energy, metabolism, and cellular processes as outlined in the lecture notes.

Chemical evolution

The process by which simple molecules formed more complex molecules, leading to the development of cells.

Metabolism

The totality of an organism's chemical reactions.

Exergonic reactions

Reactions that release energy and have a negative free energy change (ΔG).

Endergonic reactions

Reactions that require an input of energy and result in products that contain more chemical energy.

First law of thermodynamics

Energy in the universe is constant; it cannot be created or destroyed, only transformed.

Second law of thermodynamics

Energy conversions increase the disorder (entropy) of the universe.

Entropy (S)

A measure of disorder or randomness in a system.

ATP (adenosine triphosphate)

A molecule that stores and transfers energy within cells; consists of adenine, ribose, and three phosphate groups.

Phosphorylation

The process of adding a phosphate group to a molecule, often used to activate or energize reactions.

Free energy (G)

The portion of a system's energy that can perform work; indicates the stability of a system.

ΔG (Change in free energy)

The difference in free energy between reactants and products; determines if a reaction is spontaneous.

Energy coupling

The process of using energy released from exergonic reactions to drive endergonic reactions.

Kinetic energy

The energy of motion.

Potential energy

The energy an object possesses due to its position or structure.

Metabolic rate

A measure of energy use in organisms, regulated by enzymes.

Catabolic pathways

Metabolic pathways that break down complex molecules and release energy.

Anabolic pathways

Metabolic pathways that consume energy to build complex molecules.

Hydrolysis of ATP

The reaction where ATP is broken down into ADP and phosphate, releasing energy.

Active transport

The movement of molecules across a membrane against their concentration gradient, powered by ATP.