Enzymes And Biological Reactions Flashcards
Definition of metabolism
All chemical reactions in the body
Definition of metabolic pathway
A sequence of enzyme controlled reactions in which a product of one reaction is a reactant in the next.
What is an anabolic reaction?
Building up molecules
What is a catabolic reaction?
Breaking down molecules
Properties of enzymes and chemical catalysts
- they speed up reactions
- they are not used up
- they are not changed
- high turn over number
Extracellular enzyme action
Work outside the cell
Secreted from cells by exocytosis and catalyse extracellular reactions
E.g. Amylose made in salivary glands
Intracellular, in solution, enzyme action
Act in solution inside cells
E.g. Glucose breakdown
Catabolic
Intracellular, membrane bound enzyme action
Intracellular enzymes attached to membranes
E.g. Stoma of chloroplasts catalyse synthesis of glucose
Anabolic
What is an enzyme- Substrate complex?
An enzyme acts on its substrate and makes temporary bonds at the active site.
What is the lock and key model?
Unique shape of the active site means that the enzyme can only catalyse one type of reaction.
What is enzyme specificity?
An enzyme is specific for its substrate.
What is the induced fit model?
Enzyme shape alters slightly to accommodate the substrate
E.g. Lysozyme
What is activation energy?
The minimum energy that must be put into a chemical system for a reaction to occur
How do enzymes lower activation energy?
When a substrate enters the active site of an enzyme, the shape of the molecule alters, allowing the reaction to take place at lower temperatures.
