Cell Energy

Metabolism

the totality of an organism’s chemical rections

Metabolic Pathways

begin with a specific molecule, which is then altered in a series of defined steps, resulting in a certain product

Catabolic Pathways

break down complex molecules to simpler compounds; energy stored in molecules is released

Anabolic Pathways

build complex molecules from simpler ones; energy is consumed to accomplish this

Chemical energy ​

the energy stored in the chemical bonds that make up molecules.

Lipids contain a large number of C

H bonds which store more energy than C

Kinetic energy​

energy of motion.

Thermal Energy

the total internal kinetic energy of an object due to the random motion of its atoms and molecules.

Light energy​

involves the movement of photons, which are particles of light energy.

Potential Energy​

energy stored within an object, due to the object's position, arrangement or state. energy waiting to be released as heat, light,or kinetic energy.

Thermodynamics

the study of energy transformations that occur in a collection of matter

System

the matter under study

Surroundings

everything outside the system; the rest of the universe

Isolated System

a system that can not exchange either energy or matter with its surroundings

Open System

a system in which matter and energy can be transferred between the system and the surroundings

First Law of Thermodynamics

Energy can neither be created or destroyed; energy can only be transferred and transformed from one form to another.

Second Law of Thermodynamics

Every energy transfer or transformation increases the entropy of the universe

Entropy

a measure of molecular disorder, or randomness

Exergonic: If the change in free energy is negative, the reaction occurs spontaneously

Endergonic: If the change in free energy is positive, the reaction DOES NOT occur spontaneously

Reaction Coupling

An energetically favorable reaction (like ATP hydrolysis) is directly linked with an energetically unfavorable (endergonic) reaction