AP Biology Unit 3

Enzyme

protein that speeds up chemical reactions

Substrate

the substance upon which it binds to the enzyme's active site

Enzyme-Substrate Complex

formed when a substrate binds to an enzyme's active site

Active Site

the specific region of an enzyme where a substrate binds and the reaction occurs

Activation Energy

the minimum energy required to initiate a chemical reaction

Catabolism

breaking down molecules to release energy.

Anabolism

building larger molecules from smaller ones

Catalyst

substance that speeds up a chemical reaction by lowering the activation energy

pH

a measure of how acidic or basic a solution is

Denature

to lose shape due to heat or pH changes

ATP

adenosine triphosphate, the primary energy carrier in cells.

Kinetic Energy

the energy of motion

Potential Energy

the stored energy of an object

Free Energy

the energy available to do work

Exergonic Reaction

a chemical reaction that releases energy

Endergonic Reaction

a chemical reaction that absorbs energy

Catabolic Pathway

a metabolic pathway that breaks down molecules into simpler units

Anabolic Pathway

a metabolic pathway that builds molecules from simpler units

Entropy

a measure of disorder or randomness

Energy

the capacity to do work

Activation Energy

the minimum energy needed to initiate a chemical reaction

Laws of Thermodynamics

describe how energy behaves in a system

C4 Plant

plant that utilizes the C4 carbon fixation pathway to efficiently capture carbon dioxide and minimize water loss during photosynthesis

Light capturing complexes

are essential components of photosystems that absorb light energy and transfer it to reaction centers during photosynthesis

NADPH

produced during the light reactions of photosynthesis

Light

energy absorbed by photosystems during photosynthesis that initiates the process of converting carbon dioxide into glucose

Stomata

small openings on the surface of leaves that allow for gas exchange

Stroma

fluid-filled space in chloroplasts where the Calvin cycle happens

Thylakoid

in chloroplasts that contains chlorophyll and is the site of the light-dependent reactions of photosynthesis

Reaction center

a complex of proteins and pigments that absorbs light energy during photosynthesis

Chlorophyll

green pigment in plants

Redox Reaction

a chemical reaction involving the transfer of electrons between two species

Oxidation

losing electrons during a chemical reaction

Pigments

molecules that absorb light and reflect colors

Photosynthesis

process where plants and other organisms use sunlight to make food

Photons

light particles that carry energy

Wavelength

the distance between peaks of a wave

Reduction

the gain of electrons or hydrogen ions

Photoprotection

process by which organisms prevent damage from excess light energy

ATP

primary energy carrier in cells

Heterotrophs

organisms that obtain energy by consuming other organisms

Calvin Cycle

converting carbon dioxide and other compounds into glucose

Chloroplast

where photosynthesis occurs

Grana

stack of thylakoids in chloroplasts

Photosystems

pigment complexes involved in photosynthesis that absorb light energy

Mesophyll

internal tissue of a leaf where photosynthesis happens

Photorespiration

plants consume oxygen and release carbon dioxide while using up energy

G3P

a three-carbon sugar produced in the Calvin cycle

CAM Plant

type of plant that adapts to arid conditions by fixing carbon dioxide at night and performing photosynthesis during the day

Cellular Respiration

used by organisms to convert energy from nutrients into ATP

Reduction

gain of electrons

NAD+

acts as an electron carrier that gets reduced to NADH

FADH

an electron carrier that gets reduced to FADH2 during cellular respiration

Glycolysis

converts glucose into pyruvate, producing ATP and NADH

Pyruvate Oxidation

where pyruvate is converted into acetyl-CoA

Citric Acid Cycle

acetyl-CoA is oxidized to produce ATP, NADH, and FADH2

Chemiosmosis

ATP is produced in the mitochondria

ATP Synthase

protein that synthesizes ATP from ADP

Anaerobic Respiration

process of producing energy without oxygen

Fermentation

converts sugar to acids, gases, or alcohol without oxygen