An example of a hypothetical protein macromolecule is illustrated in Fig.1.7,
which shows the twisting and folding of interconnected polypeptide chains.
Carbohydratesare important in defining the structure of cells and are a source of
immediate energy needs in living systems. These macromolecules consist of
interconnected chains or rings of carbon (C), hydrogen (H) and oxygen (O) atoms
with a ratio of H twice that of C and O. Carbohydrates include compounds such as
sugars, starches, and cellulose. The most elementary monomers of carbohydrates
are simple sugars ormonosaccharides. Two fundamental monosaccharides are
glucoseandfructose, which both have the chemical formula C 6 H 12 O 6 but have
different chemical structures as shown in Fig.1.8. These simple sugars can combine
with each other to form more complex carbohydrates. Combinations of two simple
sugars are calleddisaccharides(for example, maltose = glucose + glucose and
sucrose = glucose + fructose). Polysaccharides consist of a larger number of
simple sugars.
Nucleic acidsare the macromolecules inside of a cell that store and process
genetic or hereditary information by means of protein synthesis. The two principal
forms of nucleic acids that are essential for all forms of life aredeoxyribonucleic
acid(DNA) andribonucleic acid(RNA). The monomers that make up nucleic acids
are callednucleotides. The chemical building blocks of each nucleotide include a
sugar molecule, a nitrogenous base, and a phosphate group, as Fig.1.9illustrates.
Fig. 1.7 Example of a
hypothetical protein showing
twisted and folded
interconnected polypeptide
chains
Fig. 1.8 Glucose and fructose are two basic monomers for creating carbohydrates
16 1 Overview of Biophotonics