AP Biology unit 3 chapter 1

Metabolism

Metabolism

All chemical reactions in an organism

Metabolic pathways

Services of chemical reactions that either build complex molecules or break down complex molecules

Catabolic pathways

Pathways that release energy by breaking down complex molecules into simpler compounds

Anabolic pathways

Pathways that consume energy to build complicated molecules from simpler compounds

Kinetic energy

Energy associated with motion

Thermal energy

Energy associated with the movement of atoms or molecules

Potential energy

Stored energy

Chemical energy

Potential energy available for release in a chemical reaction

Thermodynamics

The study of energy transformations in matter, the laws apply to the universe as a whole

1st law of thermodynamics

Energy cannot be created or destroyed. Energy can be transferred or transformed

2nd law of thermodynamics

Energy transformation increases the entropy (disorder) of the universe, During energy transfers or transformations, some energy is unusable and often lost as heat

Free energy

Determines the likelihood of reactions in organisms or if the reactions are energetically favorable

Exergonic reactions

Reactions that release energy, reaction is spontaneous

Endergonic reactions

Reactions that absorb energy, reaction is not spontaneous and obsorbs free energy

Cells perform 3 kinds of work

• Mechanical- movement

• Transport- pumping substances across membranes

• Chemical- synthesis of molecules

Phosphorylation

The released phosphate moves to another molecule to give energy

Allosteric enzymes

Has two binding sites (active and allosteric). Allosteric site regulates the on and off of the enzyme

Allosteric regulation

Molecules bind (noncovalent interactions) to an allosteric site which results in the change of the shape and function of the active site. May result in inhibition or stimulation

Allosteric activator

Substrate binds to allosteric site and stabilizes the shape of the enzyme so that the active site remains open

Allosteric inhibitor

Substrate binds to allosteric site and stabilizes the enzyme shape to that the active sites are closed

Cooperativity

Substrate binds to one active site on an enzyme with one or more active site which stabilizes the active form