How do genetic mutations affect enzyme function?

Genetic mutations can alter the structure of an enzyme, potentially affecting its function or efficiency.

Enzymes are biological catalysts that speed up chemical reactions in the body. They are proteins, and like all proteins, they are made up of chains of amino acids. The sequence of these amino acids is determined by the genetic code. If a mutation occurs in the gene that codes for a particular enzyme, it can change the sequence of amino acids in the enzyme. This can alter the enzyme's shape or structure, which is crucial for its function.

Enzymes work by binding to specific molecules, known as substrates, and converting them into different molecules, known as products. The part of the enzyme where this happens is called the active site. The active site has a very specific shape that fits perfectly with the substrate, like a key in a lock. If a mutation changes the shape of the active site, the enzyme may no longer be able to bind to its substrate, or it may do so less efficiently. This can slow down or even stop the reaction that the enzyme is supposed to catalyse.

In some cases, a mutation may cause an enzyme to become more efficient or to catalyse a different reaction altogether. This can also have significant effects on the body's metabolism. For example, a mutation in the gene for the enzyme phenylalanine hydroxylase can cause a condition called phenylketonuria. People with this condition cannot break down the amino acid phenylalanine, which can build up in the body and cause brain damage.

In conclusion, genetic mutations can have a significant impact on enzyme function. They can alter the structure of an enzyme, affecting its ability to bind to its substrate and catalyse reactions. This can have a range of effects on the body's metabolism, from minor changes to serious metabolic disorders.