Few of us ever consider what DNA is made of? In biology parlance they’re called nucleic acids, and they are a specialized form of amino acids, which are basically proteins. Proteins are made up of carbon, hydrogen and oxygen. Carbon, hydrogen and oxygen are made up of atoms. Atoms are made up of protons, neutrons and electrons.
But stop and think for a moment, how does an atom know where to go to make 10 trillion connections?
Since when did we ever attribute intelligence to an atom? Where is this intelligence coming from that gives DNA the foresight to tell an electron where to go? If every atom acted independently, there would be an infinite array of biological species.
DNA is a double helix formed by base pairs attached to a sugar-phosphate backbone.
DNA has a spiral staircase-like structure.
Let’s take it a step further. DNA is made of chemical building blocks called nucleotides. These building blocks are made of three parts: a phosphate group, a sugar group and one of four types of nitrogen bases. To form a strand of DNA, nucleotides are linked into chains, with the phosphate and sugar groups alternating.
The four types of nitrogen bases found in nucleotides are: adenine (A), thymine (T), guanine (G) and cytosine (C). The order, or sequence, of these bases determines what biological instructions are contained in a strand of DNA. For example, the sequence ATCGTT might instruct for blue eyes, while ATCGCT might instruct for brown eyes.
Each DNA sequence that contains instructions to make a protein is known as a gene. The size of a gene may vary greatly, ranging from about 1,000 bases to 1 million bases in humans.
The complete DNA instruction book, or genome, for a human contains about 3 billion bases and about 20,000 genes on 23 pairs of chromosomes.
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