AP Biology Energy & Cellular Respiration
aerobic respiration
A catabolic pathway that consumes oxygen and organic molecules, producing ATP. This is the most efficient process of ATP production.
fermentation
A catabolic process that makes a limited amount of ATP from glucose without an electron transport chain and that produces a characteristic end product, such as ethyl alcohol or lactic acid.
citric acid cycle / Krebs cycle
A chemical cycle involving several steps that completes the metabolic breakdown of glucose molecules begun in glycolysis by oxidizing acetyl to carbon dioxide. it occurs within the mitochondrial matrix in eukaryotic cells and in the cytosol of prokaryotes.
endergonic reaction
A non-spontaneous chemical reaction, in which free energy is absorbed from the surroundings.
Denaturation
A process in which a protein unravels, losing its specific structure and hence function; can be caused by changes in pH or salt concentration or by high temperature.
enzyme
A protein serving as a catalyst, a chemical agent that changes the rate of a reaction without being consumed by the reaction.
electron transport chain
A sequence of electron carrier molecules (membrane proteins) that shuttle electrons, using the energy from those electrons to create a proton gradient across the membrane. The energy in this gradient will be used during chemiosmosis to produce ATP.
catabolism
A series of chemical reactions that breaks down a complex molecule.
anabolism
A series of chemical reactions that builds a complex molecule.
exergonic reaction
A spontaneous chemical reaction, in which there is a net release of free energy.
competitive inhibitor
A substance that reduces the activity of an enzyme by entering the active site in place of the substrate whose structure it mimics.
pyruvic acid
Aka pyruvate. This three-carbon compound is produced during glycolysis and is needed for both the aerobic and anaerobic pathways of cellular respiration that follow glycolysis.
chemiosmosis
An energy-coupling mechanism that uses energy stored in the form of a hydrogen ion gradient across a membrane to drive cellular work, such as the synthesis of ATP. Most ATP synthesis in cells occurs by chemiosmosis.
ATP synthase
An enzyme protein complex that provides a port through which protons diffuse. This complex functions in chemiosmosis with adjacent electron transport chains, using the energy of a hydrogen ion (proton) concentration gradient to make ATP. They are found in the inner mitochondrial membrane of eukaryotic cells and in the plasma membrane of prokaryotes.
Cristae
An infolding of the inner membrane of a mitochondrion that houses electron transport chains and ATP synthase
chemical energy
Energy available in molecules for release in a chemical reaction; a form of potential energy.
alcohol fermentation
Glycolysis followed by the conversion of pyruvate to carbon dioxide and ethyl alcohol.
lactic acid fermentation
Glycolysis followed by the conversion of pyruvate to lactate, with no release of carbon dioxide.
matrix
In a mitochondrion, this is the area of the organelle inside the inner membrane.
induced fit
Induced by entry of the substrate, the change in shape of the active site of an enzyme so that it bonds more snugly to the substrate.
NADP+
Nicotinamide adenine dinucleotide phosphate, an electron acceptor that temporarily stores energized electrons produced during the light reactions of photosynthesis
NAD+
Nictinamide adenine dinucleotide, can accept an electron and act as an electron carrier in the electron transport chain in cellular respiration
reduction
The addition of electrons to a substance involved in a redox reaction.
activation energy
The amount of energy that reactants must absorb before a chemical reaction will start.
energy
The capacity to cause change, especially to do work.
cellular respiration
The catabolic pathways of aerobic and anaerobic respiration, which break down organic molecules for the production of ATP.
kinetic energy
The energy associated with the relative motion of objects.
potential energy
The energy that matter possesses as a result of its location or spacial arrangement (structure).
acetyl CoA
The entry compound for the Krebs cycle in cellular respiration, formed from a fragment of pyruvate attached to a coenzyme.
substrate-level phosphorylation
The formation of ATP by an enzyme directly transferring a phosphate group to ADP from an intermediate substrate. Type of ATP production in glycolysis and Krebs cycle
oxidation
The loss of electrons from a substance involved in a redox reaction.
oxidative phosphorylation
The production of ATP using energy of a proton gradient established by an electron transport chain where oxygen is the final electron acceptor. The final stage of cellular respiration.
substrate
The reactant on which an enzyme works.
glycolysis
The splitting of glucose into pyruvate. This occurs in almost all living cells, serving as the starting point for fermentation or cellular respiration.
metabolism
The totality of an organism's chemical reactions, consistiing of catabolic and anabolic pathways, which manage the material and energy resources of the organism.
carbon dioxide
This gas is a reactant of photosynthesis and a waste product of cellular respiration.
FADH2
This is produced in the Krebs cycle and is a reduced form of FAD, it is an electron carrier capable of creating ATP from releasing its electrons to the electron transport chain.
ADP
This is the molecule that ATP becomes when it gives up one of its three phosphate groups.
mitochondrion
This organelle in eukaryotic cells serves as the site of cellular respiration.
glucose
This sugar is manufactured during photosynthesis and is the main source of energy for plants and animals. It is metabolized during cellular respiration.
adenosine triphosphate
What does ATP stand for?
