What Is the Structure & Function of a Macromolecule?

General Structure

• In biochemistry, the majority of macromolecules consist of thousands of atoms. Also, most macromolecules are polymers, which are molecules with repeating units (monomers) that have the capability of reacting chemically to other molecules. Generally, cells have thousands of various macromolecules. The four main classes of macromolecules are proteins, carbohydrates, nucleic acids and lipids.

Proteins

• Protein is a macromolecule (polymer) composed of the same group of 20 monomers, called amino acids. Proteins can be distinguished from carbohydrates and lipids because protein also contains nitrogen. Other components of proteins include hydrogen, carbon, oxygen and sulphur.

  The human body contains tens of thousands of various proteins, each with their own configuration and purpose. Chief functions of protein macromolecules include providing the cell and organism with overall structural support; assisting with cellular metabolism; defense against harmful substances; transporting substances and helping to facilitate movement.

Carbohydrates

• Carbohydrates encompass a wide array of organic compounds. These organic compounds are made of various configurations of carbon, oxygen and hydrogen, which are arranged to form sugars, starches and cellulose.

  As it pertains to macromolecules, carbohydrates come in the form of polymers of sugar; however, instead of as simple sugars called monosaccharides (such as fructose and glucose) they come in the form of polysaccharides. Polysaccharides are sugars made of monosaccharides linked together. Polysaccharides that are considered macromolecule/polymers include a form of glucose called glycogen, as well as cellulose and starch.

  Some of main functions of carbohydrate (polysaccharide) macromolecules include providing energy storage and building material for cells and whole organisms.

Nucleic Acids

• Nucleic acids are substance made of nucleotides. Nucleotides are compounds of nitrogen bases, phosphates and a sugar. Nucleic acids are macromolecule polymers that come in the form deoxyribonucleic acid (DNA) and ribonucleic acid (RNA).

  DNA and RNA work together by creating and translating genetic information for cell function, division and growth. This genetic information ultimately determines the characteristics of an organism.

Lipids

• A lipid is a wax-like or fatty organic compound. It is the only biochemical macromolecule class that is not a polymer. Lipids encompass many substances, including sterols, waxes, cholesterol, oils, fat-soluble vitamins, monoglycerides, diglycerides and triglycerides.

  Lipids do not dissolve in water. Some of lipid macromolecules' chief functions include energy storage, insulation, structural support and cell signaling.