Unit XIX bioactive compounds and biochemistry

A bioactive compound is a compound that has an effect on a living organism, tissue or cell. In the field of nutrition bioactive compounds are distinguished from essential nutrients. While nutrients are essential to the sustainability of a body, the bioactive compounds are not essential since the body can function properly without them, or because nutrients fulfil the same function. Bioactive compounds can have an influence on health.

Bioactive compounds are found in both plant and animal products or can be synthetically produced. Examples of plant bioactive compounds are carotenoids and polyphenols (from fruits and vegetables), or phytosterols (from oils). Example in animal products are fatty acids, found in milk and fish. Some examples of bioactive compounds are flavonoids, caffeine, carotenoids, carnitine, choline, coenzyme Q, creatine, phytosterols, polysaccharides, glucosinolates, polyphenols, anthocyanins prebiotics, taurine and others.

There are two biggest classes of bioactive compounds. They are hormones and vitamins.

Hormones

Hormones are organic substances secreted by plants and animals. They are special chemical messengers in the body that are created in the endocrine glands. These messengers control most major bodily functions, e.g. such as digestion, metabolism, respiration, tissue function, sensory perception, sleep, excretion, lactation, stress, growth and development, movement, reproduction, and even mood.

Hormones affect distant cells by binding to specific receptor proteins in the target cell resulting in a change in cell function.

Hormone synthesis may occur in specific tissues of endocrine glands or in other specialized cells, which are part of the endocrine system. Hormone synthesis occurs in response to specific biochemical signals induced by a wide range of regulatory systems. The main hormone-producing glands are: hypothalamus being responsible for body temperature, hunger, moods and the release of hormones from other glands and controlling thirst, sleep and sex drive; parathyroid controlling the amount of calcium in the body; thymus, playing a role in the function of the adaptive immune system and the maturity of the thymus and producing T-cells; pancreas producing the insulin that helps control blood sugar levels; thyroid producing hormones associated with calorie burning and heart rate; adrenal producing the hormones that control sex drive and cortisol, the stress hormone; pituitary controlling other glands; pineal, also called the thalamus, producing serotonin derivatives of melatonin, which affects sleep; ovaries, only in women, secreting estrogen, testosterone and progesterone, the female sex hormones; testes, only in men, producing the male sex hormone, testosterone, and produce sperm. These glands work together to create and manage the body's major hormones.

Hormones have diverse chemical structures, mainly of 3 classes: eicosanoids, steroids, and amino acid derivatives (amines, peptides, and proteins).