Definitions Flashcards
Exergonic reaction
Catabolic.
The products have LESS energy than reactants (so change in energy, ∆G, is -ve)
Endergonic reaction
Anabolic
The products have MORE energy than reactants (so change in energy, ∆G, is +ve)
Metabolic pathway
Sequence of consecutive biochemical reactions.
The product of one reaction becomes the reactant of another.
Reciprocal regulation
The activation of one pathway while the opposite pathway is suppressed.
Allosteric enzymes
Relating to or denoting the alteration of the activity of an enzyme by means of a conformational change induced by a different molecule.
(Where the product concentration increases and that increase in product causes the product to bind to the enzyme in a different location and changes the conformation of the enzyme’s active site and it can inhibit or promote the enzyme)
Feedback inhibition
When concentration of a product rises above required level, excess concentration inhibits enzyme activity (allosteric enzyme).
Production is stopped.
When concentration of that product drops below required level, production continues again.
1st law of thermodynamics
Amount of NRG in universe is constant - cannot be created or destroyed
2nd law of thermodynamics
In all natural processes, the entropy (disorder) of the universe increases.
Phosphoryl Group Transfer
The name given to the chemical process of the transfer of the phosphoryl group (PO3) from a phosphate ester or anhydride to a nucleophile.
Energy Coupling
Transfer of energy from catabolism to anabolism, or transfer of energy from exergonic process to endergonic process. Free energy (from ATP hydrolysis) is coupled or functionally linked to the energy needs of another chemical reaction
Anabolism
The synthesis of complex molecules in living organisms from simpler ones together with the storage of energy
Catabolism
The breakdown of complex molecules in living organisms to form simpler ones, together with the release of energy
Metabolism
The chemical processes that occur within a living organism in order to maintain life.
Glycolysis
The breakdown of glucose (6C) to two pyruvate (3C)
Kinases
Enzymes that catalyse the transfer of the terminal phosphoryl group from ATP to an acceptor nucleophile.
(Subclass of transferases).
Kinases require Mg2+ for it’s activity.