3.1.1 Different forms of energy are essential to cell function

Smaller animals need to produce more energy per unit of mass due to increased radiation of heat into the environment

Kinetic energy: energy associated with motion (eg. thermal energy)

Potential energy: energy matter possesses because of its location or structure (eg. chemical energy)

3.1.2 Laws of the thermal dynamics

Metabolism代谢: the totality of an organism’s chemical reactions

Metabolism can be classified into 2 kinds:

1. Catabolic reactions分解代谢反应: separate complex molecules into energy and simple molecules
2. Anabolic reactions合成代谢反应: compose simple molecules & energy into complex molecules

Law of the thermal dynamics 热力学定律

1. First law: energy of the universe is constant
2. Second law: every energy transfer or transformation increases the entropy 熵

Living systems need to continually acquire & transform energy in order to remain alive

3.1.3 The free energy change of a reaction

Free energy refers to Gibbs free energy(G), the amount of energy available in a system to do work

Higher free energy means less stable and greater work capacity

Change in free energy: ΔG

H = G + TS