Enzymes

2.3.1 Define enzyme and active site.
An enzyme is a globular protein functioning as a biological catalyst. An active site is the site on the surface of an enzyme to which substrate or substrates bind.

2.3.2 Explain enzyme-substrate specificity.
An enzyme has an active site that fits with one specific substrate, like a lock and key.

2.3.3 Explain the effects of temperature, pH and substrate concentration on enzyme activity.
For all enzymes, there is an optimum temperature at which the maximum amount of collisions occur in the active sites. As the temperature decreases, there is less movement and fewer collisions, so enzyme activity decreases. There is a limit to which the enzyme activity can increase because at a certain temperature the enzymes denature. This means that the enzyme changes shape and no longer fits with its substrate. Also, as the substrate concentration increases, so does the enzyme activity, but there is also a limit to the increase in enzyme activity because there is a limit to how quickly the enzymes can catalyze each reaction. There is a specific pH at which the enzyme will denature, and so pH also plays a part in enzymatic activity.

2.3.4 Define denaturation.
Denaturation is a structural change in a protein that results in a loss of its biological properties.

2.3.5 Explain the use of pectinase in fruit juice production, and one other commercial applicatoin of enzymes in biotechnology.
Pectinase is used in fruit juice production to break down the acidity of the juices. Also, during oil spills, oil-digesting bacteria are used to clean up the spills since these bacteria have enzymes that can break down oil.