ABSTRACT
Like water, proteins have a central place in the cell. Proteins constitute the structure of living organisms and catalyze cellular reactions. The genetic information present in the DNA segment (gene) is expressed in the form of a protein. Proteins are thus among the most fundamental bio logical macromolecules and have versatile functions. Cells contain thousands of different pro teins, each with a specific function or biological activity, including enzymatic catalysis (biologi cal catalysts), molecular transport, nutrition, cell or organismal defense and motility, structural roles, regulation of metabolism, and many others.
