Enzymes are typically protein. They have a unique 3-D structure that is critical to their functioning. The structure of enzymes is often sensitive to changes in temperature and pH, which can alter their activity or denature them.
Definitions
Enzyme
Biological protein catalyst that speeds up a chemical reaction without being used up itself.
Metabolism
The sum pf all the chemical reactions that occur in an organism
Substrate
The molecule upon which an enzyme acts.
Active Site
The specific region of an enzyme where a substrate binds and a chemical reactions occur.
Anabolic Reaction
Smaller molecules join together to create larger ones e.g. DNA polymerase
Catabolic Reaction
Larger molecules broken down to smaller ones e.g. protease
Denatured Enzyme
Has lost its shape and can no longer function
Induced fit Theory/ Active Site Theory
Enzyme Function
Enzymes work by lowering the activation energy of a reaction. This makes it easier for the reaction to occur. They are highly specific, meaning that each enzyme only catalyse one substrate reactions. This specificity is due to the unique fit between an enzyme's active site and its substrate. The enzyme shape will return to normal once the product has been released.
Factors Affecting Enzyme Activity
Several factors can influence enzyme activity, including temperature and pH. Optimal conditions for enzyme activity vary from enzyme to enzyme, but most human enzymes perform best at a body temperature of around 37°C and at a specific pH level.
Applications of Enzymes
Bioprocessing is the use of organisms, cells or enzymes to are specific products. A bioreactor is used to produce the product. Immobilised enzymes are biological catalysts attached to an inert material. Advantages: reusable, clean product, cheaper. Used to produce antibiotics, cheese, lactose-free milk.