1.4. Enzymes - Key words Flashcards
Catalyst
Substance that speeds up a reaction without changing the substances produced or being changed itself
Enzymes
Proteins that have a very specific shape as a result of their structure. They act as biological catalysts and will only catalyse specific reactions
Specificity
Enzymes will only catalyse specific reactions due to their specific structure
Anabolic reaction
Reaction that builds up new molecules in a cell
Catabolic reaction
Reaction that breaks down substances within a cell
Metabolism
Sum of catabolic + anabolic processes in a cell
Metabolic chain (pathway)
Series of linked reactions in the metabolism of a cell
Intracellular enzymes
Enzymes that catalyse reactions within the cell
Extracellular enzymes
Enzymes that catalyse reactions outside of the cell in which they are made
Activation energy
Energy needed for a reaction to get started
Substrate
Molecule(s) on which the enzyme acts
Lock-n-key hypothesis
Substrate fits perfectly in enzyme’s active site creating a complex as a key fits a lock
Active site
Area of an enzyme that has a specific shape into which the substrate(s) of a reaction fit
Induced-fit hypothesis
Active site is considered to have a more flexible shape. The substrate fits the active site which is modified to form the complex. When products leave the complex the enzyme reverts shape
Initial rate of reaction
Measure taken to compare the rates of enzyme controlled reactions under different conditions