Question

Genetic engineering can be used to disrupt specific genes in the genome of an organism. Predict how the browning of apple slices would be affected in a strain of apples that was genetically engineered to lack functional copies of the gene encoding polyphenol oxidase. Justify your response.

Answer 1

Answer: Fruit will not brown. Browning requires a functional enzyme.

Explanation:

Genetic engineering refers to the manipulation of an organism's genes. Scientists use a variety of molecular tools and techniques to cut up and join genetic material from different species and to introduce this new hybrid DNA into another organisms. The overall goal is to add or remove an organism's genetic makeup for the better, or to transfer DNA code from one species into the other, in order to form new combinations or heritable genetic material.

Enzymatic browning is a reaction that occurs in fruits which results in negative effects on characteristics such as taste, color, and nutritional value. This reaction is a caused by phenolic compounds' oxidation by an enzyme called polyphenol oxidase, which causes the generation of dark pigments. This is often seen in apples which are rich in this enzymes and susceptible to this enzymatic browning.

If through genetic engineering, the gene encoding the enzyme responsible for the apple browing is removed, then this enzyme cannot be produced by the apple. Consequently, apples will not brown, because there will not be a polyphenol oxidase that oxidates the phenolic compounds.