GMA Biology  

The Divine Double Helix

 

Carbon is the central element to all living organisms. It is the basis to all life on earth. The feature that distinguishes an organic from inorganic molecule is that organic molecules contain carbon-hydrogen bonds, whereas inorganic molecules do not. The four major classes of organic molecules include carbohydrates, proteins,  lipids and nucleic acids.

 

 

• Nucleic Acids - Nucleic acids make up long chains of components such as DNA and RNA. DNA carries information such as genes for protein molecules to use. The RNA helps to move the DNA code from storage to where it can be us.

• Proteins - Proteins are made up of long chains of amino acids. Proteins play an important role in nearly every process that takes place in cells.

• Carbohydrates - Carbohydrates consist only of carbon, hydrogen, and oxygen. They include starches and sugars and play an important role in our daily lives.

• Lipids - Lipids include fats and waxes. They are used for long term storage of energy in life forms.

 

But where do these molecules come from?  How are they manufactured in the body? We know about cells and DNA and we know that cells can multiply but what about everything else?

 

Lets talk today about DNA and a little more about how it's built and how exactly it replicates.  DNA is an acronym that stands for Deoxyribonucleic Acid.  That's a long one.  It means its a very simple sugar (monosaccharide) that is found in the nucleus of the cell.  "Deoxyribose" is the sugar. "Nucleic" means, its in the nucleus.  But really, nucleic acids are found in just about every part of anything living, including in bacterial cells that don't have a nucleus.

 

There are five  members of nucleic acids family.  Chemists call the members (or monomers)  "nucleotides." The five pieces are adenine, thymine, cytosine and guanine and  uracil.   The monomers or members of the nucleotide family that we will look at today are the first four and usually we just refer to them by their initials: ATCG.