Life+Molecules

=__**Life Molecules**__= __**Carbohydrates:**__ Carbohydrates are organic compounds that consit of carbon, hydrogen, and oxygen. Carbohydrates are divided into four chemical groupings: [|monosaccharides], [|disaccharides], [|oligosaccharides], and [|polysaccharides]. Carbohydrates perform many roles. Those include storing energy, and providing structural support for DNA and RNA. Monosaccharides are the main fuel source for metabolism. Carbohydrates are generally called sugars. Click on the highlighted words to learn about the four chemical groupings of carbohydrates.


 * __Proteins:__**

Proteins are organic compounds made of amino acids that are arranged in a linear chain. The sequence of an amino acid chain is defined by the sequence of the gene which is encoded in the genetic code. The genetic code generally consist of twenty standard amino acids. Like other life molecules, proteins are essential parts of all organisms and participate in almost every cell function. Many proteins are enzymes that catalyze or start chemical reactions and are important for metabolism. Proteins also help structure the cytoskeleton in cells. Other proteins are important for cell signaling, immune responses, cell adhesion, and the cell cycle. Proteins are also very important in all animal's diets because animals cannot synthesize all the amino acids they need and must obtain the essential amino acids from the food they eat. To watch protein synthesis click on the following link: http://www.biostudio.com/demo_freeman_protein_synthesis.htm


 * __Lipids:__**



Lipids are a broad group of naturally occurring molecules which includes fats, waxes, sterols, and fat-soluble vitamins. The main biological functions of lipids include energy storage, as structural components of cell membranes. Lipids may be broadly defined as hydrophobic or amphiphilic small molecules; the amphiphilic nature of some lipids allows them to form structures such as vesicles, liposomes, or membranes in an aqueous environment. Like other life molecules, lipids are also used for energy storage.


 * __Nucleic Acids__**

Nucleic acids are biological molecules essential for life, and include DNA and RNA. Together with proteins, nucleic acids make up the most important macromolecules; each is found in abundance in all living things. Nucleic acids were first discovered by Friedrich Miescher in 1871. Experimental studies of nucleic acids constitute a major part of modern biological and medical research, and form a foundation for genome and forensic science, as well as the biotechnology and pharmaceutical industries. N ucleic acids are linear polymers of nucleotides. Each nucleotide consists of three components: a purine pyrimidine nucleobase a pentose sugar; and a phosphate group. The substructure consisting of a nucleobase plus sugar is termed a nucleoside. Nucleic acid types differ in the structure of the sugar in their nucleotides. Also, the nucleobases found in the two nucleic acid types are different: adenine, cytosine, and guanine are found in both RNA and DNA, while thymine occurs in DNA and uracil occurs in RNA.

For more information on Life Molecules visit the following links:

http://hyperphysics.phy-astr.gsu.edu/hbase/biology/biomol.html

http://www.ncbi.nlm.nih.gov/books/NBK21473/