Biological Molecules

Monomer

A monomer is a single unit of covalent bonds, which when strung together make a polymer. They are low in molecular weight which can combine together.

Proteins are made up of repeating amide, these are called polyamides. Likewise, nucleotides are the monomer units of DNA and RNA and the cellulose is made up of repeating β-glucose units.

Polymer

 A polymer is a chain of monomers, these giant molecules are known as macromolecules. Polymers are usually made up of about 50 monomers. Macromolecules vary as a result of different arrangements of these monomers.

The 4 simple groups of carbohydrates, lipids, proteins and nucleic acids.

Carbohydrates – composed of sugar monomers and necessary for energy storage.

Lipids – include fats, phospholipids and steroids. Lipids help to store energy, cushion and protect organs, insulate the body and form cell membranes.

Proteins – composed of amino acid monomers and have a wide variety of functions including molecular transport and muscle movement.

Nucleic Acids – include DNA and RNA. Nucleic acids contain instructions for protein synthesis and allow organisms to transfer genetic information from one generation to the next.

Carbohydrates – composed of sugar monomers and necessary for energy storage.

Lipids – include fats, phospholipids and steroids. Lipids help to store energy, cushion and protect organs, insulate the body and form cell membranes.

Proteins – composed of amino acid monomers and have a wide variety of functions including molecular transport and muscle movement.

Nucleic Acids – include DNA and RNA. Nucleic acids contain instructions for protein synthesis and allow organisms to transfer genetic information from one generation to the next.

Condensation Reaction

Condensation reactions is when two molecules join together to form a larger molecule, and a small bi-product, for example in a dehydration reaction this product is usually water. Other bi products include hydrogen chloride, methanol or acetic acids. Condensation reactions are used in the production of polymers.

When the two molecules react, the condensation is called intermolecular. An example of this is the condensation of 2 amino acids to form the peptide bond; characteristics of proteins.

If the reaction is between atoms or groups of the same molecules, the condensation is called intramolecular. A famous example of this is the Dieckmann condensation where two ester groups of a single diester molecule react to each other to lose a small alcohol molecule and form a β-ketoester.

Hydrolysis Reaction

Hydrolysis reactions is the breaking down of large molecules into smaller ones by the addition of a water molecule, for example converting polysaccharides to monosaccharaides with the addition of water.