Here is a term paper on the structure of DNA in humans.
DNA is a complex structure, made up of nucleic acids. These are information carriers, along with RNA the other nucleic acid. These two combine to create the guidance system for cells. As a result, they provide the knowledge to create specific proteins that define specific biological traits for both individuals, plants and humans. This information gets passed onto each generation of cells, thus making sure our eyes are a specific color or the shape of our nose.
While models of DNA appear very complicated, these are actually get various patterns of four nucleotides. It is an alphabet of sorts, but with only four specific letters. Each of these letters pairs with another specific letter. As they join together, they bind hydrogen molecules with sugar molecules and phosphate molecules. The result is a twisting ladder of sorts. In order to fit into the cell’s nucleus, the DNA continues to twist around itself, creating a circular chromosome.
For example, humans have 46 chromosomes. When a specific non-sex human cell reproduces, it receives two copies of each set of chromosomes. But a sex cell receives only one copy of each set of chromosomes. The reason is that when the sperm and egg combine, they will then together have the required two sets of chromosomes. If they had multiple copies, it would be unable to bind property to create a new human.
Before the DNA can pass on the information to a new cell, it needs to create a duplicate of itself. Essentially, it unzips, makes a copy by binding new nucleotides to each side of the unzipped DNA. The process begins when a specific enzyme nicks the double helix, causing them to begin to separate.
Small proteins bind to the keep the DNA unzipped, while other enzymes begin the process of bind new nucleotides to both sides. Another enzyme does the proofreading, making sure that both copies are accurate. Eventually, the DNA is sealed and curls back up.
Once the copy of DNA is complete, the cell begins the process of duplicating everything else, including the organelles. Then the nucleus splits and two new cells are born.
So what does DNA carry the instructions for? Basically, the DNA provides the information needed for the body to create a variety of proteins, specific biological characteristics and even instructions on how to handle poisonous substances, like snake venom. Other information includes how to handle hormones, create storage facilities within the cells and especially protective proteins that deal with a variety of invaders.
Three nucleotides create a word and each of them defines with amino acids are part of each protein. There are 64 potential codon patterns, but only 20 amino acids, so some replication does occur within the genetic code. Still, by use of these patterns, we can look in the mirror and see all the variety and detail these patterns can provide.
Then by alternating the various codon, other patterns can emerge. Depending on the protein, it can take anywhere from 100 to 1,000 different codons to create it. The amount of detail and work to create the smallest detail in a plant, animal or human is incredible.
As in any building process, there is a starting and stopping point. Thus, when a list of codons comes together to create a protein, it also has a starting point and an enzyme that tells the codon list it is complete.
So how does a protein actually get produced? First a working copy of DNA is produced, called the mRNA. It then heads to a specific area of the cell to begin production. Ribosomes are essentially the assembly line workers and they use the detail from the mRNA to create the various proteins. The end result is that thousands of proteins are being produced constantly by the body.
Different cells also divide at different rates. Some divide for a specific number of times and then they stop dividing and simply die off. Other are constantly replicating themselves. Still others can be forced to divide based on injury or potential need. The body is constantly monitoring the production of both proteins and cells to keep the body’s balance in check.