“Spore” — a small, usually single-celled reproductive body that is highly resistant to dehydration and heat and is capable of growing into a new organism, produced especially by certain bacteria, fungi, algae, and nonflowering plants.

“Selenium” — a component of the antioxidant enzyme, glutathione peroxidase. Glutathione peroxidase works with vitamin E in preventing free radical damage to cell membranes. In addition, selenium appears to have antioxidant properties on its own and plays a role in cancer, cardiovascular disease, enhancing immune function, inflammatory conditions, and cataracts.

“Retinol” — the chemical name for vitamin A.

“Redox reaction” — another term for an oxidation-reduction reaction. A redox reaction is any reaction in which electrons are removed from one molecule or atom and transferred to another molecule or atom. In such a reaction, one substance is oxidized (loses electrons) while the other is reduced (gains electrons).

“Receptor” — a protein on, or protruding from the cell surface to which select chemicals can bind. Binding of a specific molecule (ligand) may result in a cellular signal, or the internalization of the receptor and the ligand.