Identification of Biological Important Compounds

Valentina Zunarelli

IB Biology Practical

Identification of Biological Important Compounds

Introduction

Starch is a common name applied to a white, powdery, odorless, tasteless, complex carbohydrate, (C6H10O5)x, it is found in the seeds of cereal plants and in bulbs and tubers in great amounts. Starch is manufactured by green plants during the process of . It forms part of the cell walls in plants, constitutes part of rigid plant fibers, and serves as a kind of energy storage for plants.

Sugar, chemical compounds in the carbohydrate group that are readily soluble in water; are colorless, odorless, and usually crystallizable; and are more or less sweet in taste. In general, all monosaccharides, disaccharides, and trisaccharides are termed sugars, differently from polysaccharides such as , , and glycogen. Sugars, which are widely distributed in nature, are manufactured by plants during the process of and are found in many animal tissues.

Proteins are a large number of organic compounds that make up living organisms and are essential to their functioning. Proteins are composed of units of about 20 different , which, in turn, are composed of carbon, hydrogen, oxygen, nitrogen, and sometimes sulfur.

Lipids are a family of naturally occurring compounds grouped together by their relative insolubility in water and solubility in nonpolar solvents. These are naturally occurring molecules that can be isolated from cells and tissues by extraction using nonpolar organic solvents, such as absolute ethanol. Lipids are hydrophobic. This group of molecules includes fats and oils, waxes, phospholipids, ...