Types of Biological Macromolecules

Macromolecules are an essential part of nutrition. The molecules are categorized as lipids, proteins, carbohydrates and nucleic acids. These macromolecules are consumed from the diet and broken down in the digestive track of the body. They are stored and used for energy to provide the cell with the coupling reactions necessary for cellular function. Each molecule provides different elements and waste products excreted from the body.

Creation

• Macromolecules are formed by dehydration reactions in the body. Dehydration reactions form bonds. The bonds link monomers together, forming long chains of macromolecules. For instance, fatty acid chains are bonded together and form long lipid macromolecules. These lipids are later used for energy, or they are stored in adipose tissue for future use.

Carbohydrates

• Carbohydrates are commonly called sugars. Carbohydrates are used in the creation of pyruvates, which are passed to the citric acid cycle in mitochondria for energy. There are three types of sugars. Monosaccharides are the monomer units that create larger polysaccharides. Disaccharides are two monomer units bonded together.

Proteins

• Proteins are long chains of amino acids. They are found in the muscles of the meat products. Proteins have a three-dimensional structure, which gives the protein its function. The amino acids have different functional "R" groups, which are what give molecules their interactivity with other amino acids to form the three-dimensional structures through hydrogen bonds, sulfide bridges and hydrophobic forces. The protein is broken down in the body, and the nitrogen removed and sent to the kidneys for excretion in the form of urea.

Lipids

• Lipids are made up of large chains of fatty acids. They are the waxes, fats and oils consumed in the diet. Lipids are saturated and unsaturated. Saturated fatty acids are molecules with as many hydrogen-carbon bonds as possible, meaning no double bonds exist. These types of lipids pack densely in tissue, since "kinking" is formed from double bonds. Unsaturated fatty acids have double bonds, which cause "kinks" in the packing of the molecule. These kinks are what clog vessels and cause blockages.

Nucleic Acids

• Nucleic acids are long polymers of nucleotide elements. A nucleotide is made up of a phosphate and sugar backbone with a nitrogenous base. The nitrogenous base is made up of one of the four bases--guanine, cytosine, adenine and thymine. In RNA molecules, thymine is replaced by an alternative base called uracil. These nitrogenous bases hydrogen bond to form the famous double helix in DNA.