Enzymes Flashcards
(18 cards)
Active site
Indented area on the surface on an enzyme molecule, with a shape that is complimentary to the shape of the substrate molecule.
Catalyst
Chemical that speeds up the rate of reaction and remains unchanged and reusable at the end of the reaction.
Extracellular
Outside the cell
Intracellular
Inside the cell.
Metabolic/Metabolism
The chemical reactions that take place inside living cells or organisms.
Product
Molecule produced from substrate molecules, by an enzyme-catalysed reaction.
Substrate
Molecule that is altered by an enzyme-catalysed reaction.
Cofactor
A substance that has to be present to ensure that an enzyme-catalysed reaction takes place at the appropriate rate.
Enzyme-substrate complex
Complex formed by temporary binding of enzyme and substrate molecules during an enzyme-catalysed reaction.
Enzyme-product complex
Enzyme molecule with product molecule in its active site. The two are joined temporarily by non covalent forces.
Q10
Temperature coefficient, calculated by dividing the rate of reaction at (T+10)C by the rate of the reaction at TC.
Concentration
Number of molecules per unit volume.
Competitive inhibition
Inhibition of an enzyme, where the inhibitor molecule has a similar shape to that of the substrate molecules and competes with the substrate for the enzyme’s active site. It blocks the active site and prevents formation of enzyme-substrate complexes.
Inhibitor
A substance that reduces or stops a reaction.
Non-competitive inhibitor
Inhibition of an enzyme, where the competitor molecule attaches to a part of the enzyme molecule but not the active site. This changes the shape of the active site, which prevents ES complexes from forming, as the enzyme active site is no longer complementary in shape to the substrate.
Denatured
The irreversible change of shape/loss of tertiary structure in proteins. This results in them no longer being able to function. Their shape unravels due to extremes of pH or high temperatures.
Buffers
Something that resists changes in pH.
Limiting factors
An environmental factor that limits the rate of a biological process. When a process is controlled by a number of factors, the factor that is least in supply will limit the process.
