ap bio test chapter 8

Catabolism

A cellular process that breaks down large molecules into smaller molecules.

Anabolic pathways

Pathways that consume energy to build polymers from monomers.

First law of thermodynamics

The conservation of energy; it states that energy cannot be created or destroyed.

Entropy

A measure of disorder or randomness in the universe, which increases when energy is transformed.

Second law of thermodynamics

Discusses the increase of entropy when energy is transferred or transformed; cells requiring a constant input of energy is an example.

The increasing complexity of organisms over time is consistent with what?

the second law of thermodynamics

Potential energy

Chemical energy that is waiting to be released from the breaking of bonds; such as energy-rich food molecules.

G=H-TS

The equation representing free energy, where G is free energy, H is total energy, S is entropy, and T is temperature.

Energy coupling

The transfer of free energy from catabolic or anabolic pathways; ATP is crucial in this cycle because it provides the energy between the exergonic and endergonic reactions

ATP (Adenosine Triphosphate)

A molecule that stores energy; it has three phosphates compared to ADP which has two phosphates.

Catabolic pathways

coupled with anabolic pathways to supply energy in the form of ATP

Enzyme-catalyzed reactions

Reactions that are faster due to the presence of an enzyme that acts as a catalyst without changing the end result. Adding a catalyst will increase the rate of a chemical reaction

Activation energy

The thermodynamic barrier that must be overcome for reactants to interact and form products.

Induced fit model

A model where the binding of a substrate changes the shape of the enzyme's active site.

Why does enzymes increase the rate of chemical reactions?

because they lower the amount of activation energy needed

Competitive inhibitor

A substance that inhibits or prevents the effect of an enzyme by competing with the substrate.

What can increased temperatures, like a fever do to the body?

it can change the folding of the enzymes and their function

Noncompetitive inhibitors

Substances that decrease the rate of enzyme reactions by changing the shape of the reactant.

Endergonic reaction

A reaction that absorbs positive energy into a system.

Exergonic reactions

Reactions that release or use energy during the process.

ATP cycle

The process by which ATP stores energy for cellular work, loses a phosphate to become ADP, and then picks up a phosphate to reform ATP.