Enzymes are proteins that catalyze chemical reactions, without being consumed by the
Each enzyme has a groove called an active site in which a substrate, the
reactant that the enzyme acts on, fits into (Helms
Once the substrate is in the active
site, the R groups of the amino acids in the active site make the active site close in around the
substrate and hold it firmly, which is called an induced fit. The induced fit helps an enzyme
catalyze reactions by bringing the chemical groups of the active site closer to the substrate. The
structure of an enzyme’s active site, a consequence of the enzyme’s amino acid sequence, and
the compatible shape of the substrate determines its specificity (Campbell and Reece, 2008).
The experiments are performed with catecholase, an enzyme found in potatoes.
the compound catechol, located in potatoes, meets oxygen, it is oxidized and turned into
benzoquinone, and oxygen is reduced and makes water.
Catecholase catalyzes this reaction
between catechol and oxygen.
The chains of benzoquinone molecules that form are part of the
red and brown melanoid pigments, thus turning a potato dark when it is exposed to oxygen.
experiments will be analyzed by observing the color benzoquinone gives (Helms
Because an enzyme is a protein, whatever affects proteins should affect enzymes as well.
Proteins breaking down, or denaturing results from altered pHs, temperatures, and concentrations
of the protein’s environment (Helms
., 1998). In this experiment, the effects of pH,
temperature, enzyme concentration, and substrate concentration will be tested on the enzyme
pH is a measure of hydrogen ion and sodium hydroxide ion concentration.
A change in
the presence of those ions can interfere with the molecular structure of a protein, changing its