ISBN-13: 9783639864243 / Angielski / Miękka / 2016 / 120 str.
Vitamins are organic nutrients which are essential for life. The human body requires these nutrients to ensure normal metabolism, growth and physical well-being. Most vitamins are not made in the body, or only in insufficient amounts to meet our needs. They therefore have to be obtained primarily through the food we eat. Thus, the term is conditional both on the circumstances and on the particular organism. For example, ascorbic acid is a vitamin for humans, but not for most other animals, and biotin and vitamin D are required in the human diet only in certain circumstances. Alkaloids are a chemically heterogeneous group of approximately 2,500 basic nitrogen containing substances found in about 15 percent of all vascular land plant and in more than 150 plant families. In plants, alkaloids due to their basic nature generally exist as salts of organic acids like acetic acid, oxalic acid, citric acid, malic acid, lactic acid, tartaric acid, tannic acid, etc. and some feeble basic alkaloids like nicotine etc. A few alkaloids also occur as glycosides of sugars like glucose, rhamnose, and galactose. The concentration of alkaloids in plant depends upon the season, age and locality.