Energy

3 types of energy

general energy, kinetic energy, potential energy

Energy

ability to do work or promote change

Kinetic energy

movement of energy

Potential energy

stored energy

Thermodynamics

energy transfers and transformations

Law of thermodynamics

1st Law: energy is neither created nor destroyed, it can be transferred or transformed

2nd Law: entropy (disorder, chaos and randomness) of molecules, increases with energy transfers and transformation

Free energy (G)

a measure of the amount of usable energy (energy that can do work) in that system

Exergonic reactions

negative G ( ΔG < 0), reactants have more free energy than products, releases free energy, spontaneous

Endergonic reactions

positive G (ΔG > 0), reactants have less free energy than products, uses free energy, not spontaneous

Energy Coupling

an endergonic reaction is coupled with an exergonic reaction

ATP

energy currency of a cell

Metabolism

the sum of all chemical reactions that sustain life within an organism, transforming food into energy, building materials, and waste

Metabolic pathway

multiple enzymes

Phosphorylated intermediates

temporary, high-energy molecular species formed during chemical reactions, phosphate group is covalently attached to a substrate or enzyme

Phosphorylation

chemical process of adding a phosphate group to an organic molecule (protein, enzyme, sugar)

Anabolic reaction

endergonic; builds molecules in cells

Catabolic reaction

exergonic; destroys molecules in cells, free energy building blocks, obtain energy, stored in energy intermediates