AP Biology Unit 3: Cellular Energetics Diagram | Quizlet

enzyme

a substance produced by a living organism that acts as a catalyst to bring about a specific biochemical reaction.

anabolic pathways

consume energy to build complex molecules from simpler ones

catabolic pathways

Metabolic pathways that release energy by breaking down complex molecules into simpler compounds.

substrate

reactant of an enzyme-catalyzed reaction

Denaturation

In proteins, a process in which a protein unravels and loses its native conformation, thereby becoming biologically inactive.

Photosynthesis

process by which plants and some other organisms use light energy to convert water and carbon dioxide into oxygen and high-energy carbohydrates such as sugars and starches

active site

a region on an enzyme that binds to a protein or other substance during a reaction.

Thylakoid

a membrane system found within chloroplasts that contains the components for photosynthesis

activation energy

the minimum amount of energy required to start a chemical reaction

Photosystem I

Passes electrons down the electron transportation chain and reduces NADP+ into NADPH

Endergonic

A chemical reaction that requires the input of energy in order to proceed.

RuBP

a five-carbon carbohydrate that combines with CO2 to form two molecules of PGA in the first step of the Calvin cycle

Exergonic

Chemical reactions that release energy

ATP

main energy source that cells use for most of their work

allosteric site

A site on an enzyme other than the active site, to which a specific substance binds, thereby changing the shape and activity of the enzyme.

competitive inhibitor

substance that resembles the normal substrate competes with the substrate for the active site

non-competitive inhibitor

A substance that reduces the activity of an enzyme by binding to a location remote from the active site, changing its conformation so that it no longer binds to the substrate.

catalysis

the acceleration of a reaction rate by a molecule that is unchanged by participating in the reaction

coupled reactions

pairs of chemical reactions in which some of the energy released from the breakdown of one compound is used to create a bond in the formation of another compound

Chloroplast

organelle found in cells of plants and some other organisms that captures the energy from sunlight and converts it into chemical energy

Autotroph

An organism that makes its own food

light-dependent reactions

reactions of photosynthesis that use energy from light to produce ATP and NADPH

Calvin Cycle

reactions of photosynthesis in which energy from ATP and NADPH is used to build high-energy compounds such as sugars

Stroma

fluid portion of the chloroplast; outside of the thylakoids

Chlorophyll

A green pigment found in the chloroplasts of plants, algae, and some bacteria

Stomata

Small openings on the underside of a leaf through which oxygen and carbon dioxide can move

electron transport chain

A sequence of electron carrier molecules (membrane proteins) that shuttle electrons during the redox reactions that release energy used to make ATP.

Photosystem II

One of two light-harvesting units of a chloroplast's thylakoid membrane; it uses the P680 reaction-center chlorophyll.

cytochrome complex

group of reversibly oxidizable and reducible proteins that forms part of the electron transport chain between photosystem II and photosystem I

ATP synthase

Large protein that uses energy from H+ ions to bind ADP and a phosphate group together to produce ATP

Chemiosmosis

A process for synthesizing ATP using the energy of an electrochemical gradient and the ATP synthase enzyme.

NADPH

An electron carrier involved in photosynthesis. Light drives electrons from chlorophyll to NADP+, forming NADPH, which provides the high-energy electrons for the reduction of carbon dioxide to sugar in the Calvin cycle.

Rubisco

enzyme that converts inorganic carbon dioxide molecules into organic molecules during the final step of the Calvin cycle

G3P

a molecule that is made in the Calvin cycle; glucose is formed when two of these molecules combine

TERM

cellular respiration

DEFINITION

Process that releases energy by breaking down glucose and other food molecules in the presence of oxygen

TERM

Mitochondria

DEFINITION

An organelle found in large numbers in most cells, in which the biochemical processes of respiration and energy production occur.

Glycolysis

A metabolic process that breaks down carbohydrates and sugars through a series of reactions to either pyruvic acid or lactic acid and release energy for the body in the form of ATP

Link reaction

Stage of aerobic respiration that links glycolysis with the Krebs cycle. In eukaryote cells it occurs in the mitochondrial matrix.

Citric Acid Cycle (Krebs Cycle)

- 2 Pyruvates enter the mitochondrion

- releases 2 ATP, 6NADH, and 2 FADH2 for each glucose

Electron Transport Chain (ETC)

series of electron carrier proteins that shuttle high-energy electrons during ATP-generating reactions

oxidative phosphorylation

The production of ATP using energy derived from the redox reactions of an electron transport chain; the third major stage of cellular respiration.

FADH2

A molecule that stores energy for harvest by the electron transport chain.

fermentation (anaerobic respiration)

enable cells to produce ATP without the use of oxygen

lactic acid fermentation

A series of anaerobic chemical reactions using pyruvic acid that supplies energy when oxygen is scarce to produce lactic acid or lactate

ethanol fermentation

a form of anaerobic respiration found in yeast and bacteria to produce CO2, ethanol and NAD+