Terms
Acetyl Coenzyme A
-
A small molecule that carries acetyl functional groups in cells. Composed of an
acetyl group attached to a coenzyme A molecule. The starting product of the
citric acid cycle.
Acontinase
-
The citric acid cycle enzyme responsible for catalyzing the reaction that
converts citric acid to isocitrate with the release of water.
Adenisine Triphosphate (ATP)
-
The molecule from which cells derive energy. Comprised of an adenisine molecule
bonded to three phosphates, each phosphate bond contains energy, especially the
third bond. By breaking that one bond and reducing ATP to adenisine
diphosphate (ADP), the cell can get the energy to carry out its various
processes.
Alpha-ketoglutarate dehydrogenase
-
The citric acid cycle enzyme responsible for catalyzing the reaction that
converts alpha-ketoglutarate to succinyl-CoA with the release of carbon dioxide
and the production of NADH from NAD.
Amphibolic
-
A term used to describe a process that has both anabolic and catabolic
properties.
Anabolic
-
Term describing enzyme-catalyzed reactions in a cell that involves the synthesis
of complex molecules out of simpler subunits and which uses energy.
Catabolic
-
Term describing enzyme-catalyzed reactions in a cell that involve the
degradation of molecules into more simple subunits with the release of energy.
Citrate synthase
-
The citric acid cycle enzyme responsible for catalyzing the reaction that
condenses acetyl-CoA with oxaloacetate to yield citric acid.
Citric acid cycle
-
Also known as the Krebs Cycle; a metabolic pathway found in
aerobic organisms that oxidizes acetyl
coA groups to carbon dioxide and water, producing 1 ATP, and a number of
coenzymes that play a vital role in the next step of respiration, oxidative
phosphorylation.
Coenzyme A
-
A molecule used to enzymatically transfer acetyl groups in a cell.
Dihydrolipoyl transacetylase
-
One of three enzymes that make up the pyruvate dehydrogenase multienzyme
complex. Responsible for catalyzing the addition of a CoA molecule to the
acetyl-lipoamide structure.
Flavin adenine dinucleotide
-
A coenzyme that participates in oxidation and reduction reactions by
accepting and donating hydrogen atoms. Involved particularly in oxidations and
reductions of carbon-carbon double and triple bonds.
Fumarase
-
The citric acid cycle enzyme responsible for catalyzing the reaction that
converts fumarate to L-malate with the release of water.
Glycolysis
-
A metabolic pathway occurring in the cell
cytosol. Glycolysis
comprises a series of reactions that taken in their entirety convert glucose to
pyruvate and synthesizes ATP.
Guanosine triphosphate
-
A molecule that is similar in both form and function to ATP.
Isocitrate dehydrogenase
-
The citric acid cycle enzyme responsible for catalyzing the reaction that
converts isocitrate into alpha-ketoglutarate in a two-step mechanism that leads
to the production of a molecule of NADH and carbon dioxide.
Malate dehydrogenase
-
The citric acid cycle enzyme responsible for catalyzing the reaction that
converts L-malate into oxaloacetate with the production of a NADH molecule.
Metabolism
-
All the reactions occurring in an organism that participate in the acquisition
or conversion of energy for use in the organism.
Oxaloacetate
-
Four-carbon molecule that binds with acetyl CoA in the first step of the citric
acid cycle to form six-carbon citric acid. Over the course of a series of reactions, the
citric acid is broken back down into two CO2 molecules and
oxaloacetate, allowing for the cycle to being again while producing ATP and a number of coenzymes.
Oxidation
-
A reaction that involves the overall loss of electrons from a specific molecule
or atom. Can occur with the addition of an oxygen or by the removal of a
hydrogen.
Oxidative phosphorylation
-
A process occurring in the
mitochondria
that results in the formation of ATP from the flow of electrons to oxygen.
Pyruvate dehydrogenase
-
One of three enzymes that compose the pyruvate dehydrogenase multienzyme
complex. Responsible for adding TPP to pyruvate with the release of carbon
dioxide.
Pyruvate dehydrogenase multienzyme complex
-
An overarching name given to three enzymes which catalyze the reaction that
converts pyruvate to acetyl-CoA.
Reduction
-
A reaction that results in the overall gain of electrons to a specific molecule
or atom. Can occur with the addition of a hydrogen atom or by the removal of an
oxygen atom.
Succinate dehydrogenase
-
The citric acid cycle enzyme responsible for catalyzing the reaction that
converts succinate to fumarate with the production of a molecule of FADH.
Succinyl-CoA synthetase
-
The citric acid cycle enzyme responsible for catalyzing the reaction that
converts succinyl-CoA to succinate.
