The Effect that Copper Sulphate has on the Action of the Enzyme Catalase Essay Example

and thus cause cell death and injury. However, the human body has developed various mechanisms in order to protect itself from the damaging effects of free radicals. There are enzymes, such as catalase, which decompose peroxides and transition metals.Heavy metals tend to be non-competitive inhibitors, which means that they inhibit the action of the enzyme-controlled reactions by attaching themselves to the enzyme molecule outside of the active site, thereby preventing the enzyme carrying out its normal catalytic function. In this case, the extent of the inhibition depends entirely on the concentration of the inhibitor and cannot be varied by changing the amount of substrate present.

A normal catabolic reaction:The same reaction but with the addition of a non-competitive inhibitor:Non-competitive Inhibitors:* These are molecules that bind to some part of an enzyme other than the active site.* They have a different shape to the normal substrate.* They change the shape of the active site, which no longer allows binding of the substrate.* Some substrate molecules may reach the active site before the non-competitive inhibitor.

* The rate of reaction is reduced.* Finally they leave their binding sites, but substrate molecules do not compete for these, so they have a greater inhibitory effect.How Will Copper Sulphate Affect Catalase?Catalase contains Fe in its active site (bound to a prosthetic group known as heme). Cu++ may inhibit catalase by displacing the Fe from the enzyme.

If the Cu is removed and Fe added back, activity would likely be restored. Cu++ can have other effects on enzymes. For example, the copper may be binding to negatively charged amino acids in the enzyme that are required for activity. This effect is easy to

envision if such an amino acid is in or near the active site of the enzyme. However, even amino acids at some distance from the active site (but still part of the enzyme) can influence activity if altering the amino acid changes the conformation of the protein such that activity is lost.