Chapter 3 Flashcards
Activated carrier that donates the carbon atoms in its readily transferable acetyl group to many metabolic reactions, including citric acid cycle and fatty acid biosynthesis.
acetyl CoA
A small molecule that stores energy or chemical groups in a form that can be donated to many different metabolic reactions.
Activated carrier
The energy that must be acquired by a molecule to undergo a chemical reaction.
Activation energy
Nucleoside diphosphate produced by hydrolysis of the thermal phosphate of ATP.
ADP
Set of metabolic pathways by which large molecules are made from smaller ones.
Anobolism
An enzyme-catalyzed process by which complex molecules are formed from simply substances by living cells; also called anabolism.
Biosynthesis
Set of enzyme-catalyzed reactions by which complex molecules are degraded to simpler ones with release of energy; intermediates in these reactions are sometimes called catabolites.
Catabolism
The acceleration of a chemical reaction by lowering its activation energy; enzymes perform this role in cells.
Catalysts
Linked pair of chemical reactions in which free energy released by one reaction serves to drive the other reaction.
Coupled reaction.
Process by which molecules and small particles move form one location to another by random, thermally driven motion.
Diffusion
Thermodynamic quantity that measures the degree of disorder in a system.
Entropy
A protein that catalyzed a specific chemical reaction.
Enzyme
State in which the forward and reverse rates of a chemical reaction are equal so that no net chemical change occurs.
Equilibrium
For a reversible chemical reaction, the ration of substrate to product when the rates of the forward and reverse reactions are equal.
Equilibrium constant
Energy that can be harnessed to do work, such as driving a chemical reaction.
Free energy
The concentration of substrate at which an enzyme works at half its maximum rate/velocity; serves as a measure of how tightly the substrate is bound.
KM
The sum total of the chemical reactions that take place in the cells of a living organism.
Metabolism
Activated carrier widely used in the energy-producing breakdown of sugar molecules.
NaDH
Used as an electron donor in biosynthetic pathways. In the process it is oxidized to NADP.
NADPH
Removal of electrons from an atom, as occurs during the addition of oxygen to a carbon atom or when a hydrogen is removed from a carbon atom. The opposite is reduction.
Oxidation
Addition of electrons to an atom, as occurs during the addition of hydrogen to a carbon atom or the removal of oxygen from it. The opposite is oxidation.
Reduction
General term for any process in a cell in which the uptake of molecular oxygen is coupled to the production of CO2.
Respiration
A molecule on which an enzyme acts.
Substrate
The number of substrate molecules an enzyme can convert into product per second.
Turnover number
Small molecule used to carry and transfer acetyl groups needed for a variety of metabolic reactions, such as the synthesis of fatty acids.
Coenzyme A
Atom or molecule that readily takes up electrons, thereby becoming reduced.
Electron acceptor
Molecule capable of picking up an electron from a molecule with weak electron affinity and transferring it to a molecule with a higher electron affinity.
Electron carrier
Molecule that easily gives up an electron, thereby becoming oxidized.
Electron donor
Covalent bond whose hydrolysis releases an unusually large amount of free energy under the conditions existing in a cell.
High-energy bond
