Monomeric biomolecules

Separating Biomolecules In studying a particular biomolecule (a protein, nucleic acid, carbohydrate, or lipid) in the laboratory, the biochemist first needs to separate it from other biomolecules in the sample—that is, to purify it. Specific purification techniques are described later in the text. However, by looking at the monomeric subunits of a biomolecule, you should have some ideas about the characteristics of the molecule that would allow you to separate it from other molecules. For example, how would you separate (a) amino acids from fatty acids and (b) nucleotides from glucose ... 

Structural elucidation of natural macromolecules is an important step in understanding the relationships between the chemical properties of a biomolecule and its biological function. The techniques used in organic structure determination (NMR, IR, UV, and MS) are quite useful when applied to biomolecules, but the unique nature of natural molecules also requires the application of specialized chemical techniques. Proteins, polysaccharides, and nucleic acids are polymeric materials, each composed of hundreds or sometimes thousands of monomeric units (amino acids, monosaccharides, and nucleotides, respectively). But there is only a limited number of these types of units from which the biomolecules are synthesized. For example, only 20 different amino acids are found in proteins but these different amino acids may appear several times in the same protein molecule. Therefore, the structure of... 

Nucleic acids Nucleic acids are biomolecules which are found in the nuclei of all living cells in form of nucleoproteins. They are biopolymers in which the repeating structural unit or monomeric unit is a nucleotide (polynucleotides). Each nucleotide consists of three components—... 

Unlike other biomolecules, lipids are generally not made from repeating monomeric units. 

Proteins are essential constituents of all organisms. Most tasks performed by living cells require proteins. The variety of functions that they perform is astonishing. In animals, for example, proteins are the primary structural components of muscle, connective tissue, feathers, nails, and hair. In addition to serving as structural materials in all living organisms, proteins are involved in such diverse functions as metabolic regulation, transport, defense, and catalysis. The functional diversity exhibited by this class of biomolecules is directly related to the combinatorial possibilities of the monomeric units, the 20 amino acids. 

Polynucleotides are the group of natural polymers in which the monomeric units are formed by a type of biomolecule known as nucleotides. Nucleotides are basically nucleoside phosphates. Nucleoside is the part of a nucleotide that is formed by glycosidic linkage between a monosaccharide and a type of nitrogenous compound called a nucleotide base. The nucleotide base may be of two types a purine base or a pyrimidine base. Depending... 

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