BIOMOLECULES AND ENZYMES

Detailed explanation-1: -Oxygen in the air can cause sliced fruit to brown, a process called enzymic browning (an oxidation reaction).

Detailed explanation-2: -Trapped inside the tissue of fruits are molecules known as enzymes. These enzymes help fruit ripen and turn brown. When fruit is cut or starts to break down, the enzyme is released from the tissue of the fruit and exposed to air which causes the fruit to rapidly change color. This is known as enzymatic browning.

Detailed explanation-3: -When an apple is cut (or bruised), oxygen is introduced into the injured plant tissue. When oxygen is present in cells, polyphenol oxidase (PPO) enzymes in the chloroplasts rapidly oxidize phenolic compounds naturally present in the apple tissues to o-quinones, colorless precursors to brown-colored secondary products.

Detailed explanation-4: -This unappetizing phenomenon is actually due to a chain of biochemical reactions known as “enzymatic browning.” When an apple is injured (or cut into pieces), the plant tissue is exposed to oxygen.

Detailed explanation-5: -Oxidation occurs when a substance is exposed to oxygen. For fruit, oxidative browning occurs when enzymes interact with amino acids in the presence of oxygen, which then causes brown pigments to form. Pigments make up the natural coloring of plant and animal tissues.