AP Bio Unit 3 Review

Enzyme

Proteins that speed up reactions by lowering activation energy.

Active Site

The region of an enzyme where the substrate binds and undergoes a chemical reaction.

Denatured

When an enzyme loses its shape and function due to extreme conditions such as high temperature or pH.

Cofactors

Non-protein helper molecules that are required for enzyme activity.

Feedback Inhibition

A process where key metabolic enzymes are inhibited by the end product of the pathway they control.

Competitive Inhibition

A form of enzyme inhibition where a molecule competes with the substrate for binding to the active site.

Noncompetitive Inhibition

A form of inhibition where an inhibitor binds to a site other than the active site, altering the enzyme's shape.

Calvin Cycle

Light-independent reactions in photosynthesis where ATP and NADPH are used to build sugars from carbon dioxide.

ATP (Adenosine Triphosphate)

The primary energy carrier in cells, releasing energy when hydrolyzed to ADP and inorganic phosphate.

Oxidative Phosphorylation

The production of ATP coupled with the movement of electrons through the electron transport chain.

Photosystem II (PSII)

The first photosystem in the light reactions, responsible for splitting water and producing oxygen.

Photosystem I (PSI)

The second photosystem in the light reactions, responsible for the production of NADPH.

Redox Reaction

A chemical reaction involving the transfer of electrons between two substances, involving oxidation and reduction.

Entropy

A measure of the disorder or randomness in a system, increasing in energy transformations.

Light Reactions

The phase of photosynthesis where light energy is captured to produce ATP and NADPH.

Dark Reactions

The phase of photosynthesis that uses ATP and NADPH to fix carbon dioxide into organic molecules.

Chemiosmosis

The process of generating ATP using a proton gradient across a membrane.

Glycolysis

The first stage of cellular respiration, breaking down glucose to produce ATP and NADH.

Aerobic Respiration

Cellular respiration that occurs in the presence of oxygen, fully oxidizing glucose to produce ATP.

Lactic Acid

A product of anaerobic respiration in muscle cells, causing fatigue.

Fermentation

Anaerobic process that allows ATP generation by converting glucose into products like lactic acid or ethanol.

Anabolic

Processes that build up complex molecules.

Catabolic

Processes that break down complex molecules.

Bioenergetics

The study of the flow and transformation of energy in living systems.

Redox Reaction

A chemical reaction involving the transfer of electrons, with one substance being oxidized (loses electrons) and the other being reduced (gains electrons).

First Law of Thermodynamics

Energy cannot be created or destroyed, only transferred or converted from one form to another (law of conservation of energy).

Second Law of Thermodynamics

The total entropy of an isolated system always increases over time as energy transformations are not 100% efficient.

Activation Energy

The minimum energy required to start a chemical reaction, usually needed to break bonds in reactants.

Enzyme Specificity

The property of an enzyme to bind only to specific substrates, determined by the enzyme's active site structure.

Cofactors

Non-protein molecules or ions required for enzyme activity, either as a coenzyme or a metal ion.

Competitive Inhibition

A form of enzyme inhibition where a molecule competes with the substrate for binding to the enzyme's active site.

Light Reactions

The first stage of photosynthesis, where light energy is captured by chlorophyll to produce ATP and NADPH.

Calvin Cycle

The second stage of photosynthesis, where carbon dioxide is fixed into organic molecules using ATP and NADPH produced in the light reactions.

Aerobic Respiration

Cellular respiration that occurs in the presence of oxygen, producing ATP by fully oxidizing glucose to carbon dioxide and water.

Anaerobic Respiration

Cellular respiration that occurs without oxygen, producing ATP by partially oxidizing glucose (e.g., fermentation).