When we write in English, our words and our stories are compromised of letters. 26 letters, to be exact. We’ve become so good at understanding the meaning between different words, how they can mean different things based on the way that the letters are arranged.
But when it comes down to it, you probably don’t know all that much about the letters — or should I say chemicals — that make up your body. 4 base chemicals support life. That has created everything living around us.
Isn’t that insane? 26 letters in the English alphabet, but only 4 chemicals created us.
What actually is DNA?
To understand the biology of the body, we must understand how everything alive, is compromised of those 4 nitrogen bases. Their names are Adenine (A), Thymine (T), Cytosine (C), and Guanine (G).
These nitrogen bases are where it all starts.
Our 4 lovely chemicals pair up, to write the code of your body. But, they’re very specific. A will only pair with T, and C will only pair with G. When they pair up with each other, that’s what we call base pairs.
The order of these bases is what determines the DNA’s instructions, or the genetic code.
The Makeup of DNA
Deoxyribonucleic acid (DNA) is what we call it when we group these base pairs. Your DNA holds the genetic code to your body. If we look at human beings on the chemical level, we aren’t all that different. We have 3 BILLION base pairs in our body, and 99% of them are the same in every human being.
So what makes up our DNA? They’re actually little molecules called nucleotides.
These nucleotides are made up of 3 parts; a phosphate group, a sugar group, and a nitrogen base. These nucleotides are then arranged into long strands that form a spiral, called a double helix.
DNA molecules are also very long, so long that they need to be “packaged” otherwise they won’t be able to fit into the cells. This packaging is called chromosomes. The DNA is coiled really really tightly, as each chromosome contains a single DNA molecule. Humans have 23 pairs of chromosomes that are found inside the cell's nucleus (the headquarters).
Proteins — Our structure, Transport, and Defense
DNA codes for proteins in a process called protein synthesis, which consists of 2 processes — transcription and translation. During transcription, the DNA is making a molecule called messenger RNA (mRNA). During transcription, the genetic code in mRNA is read and used to make a protein.
There are 3 types of RNA; mRNA carries the instructions from the nucleus of the cell to the cytoplasm, and ribosomal RNA (rRNA) and transfer RNA (tRNA) are involved in ordering amino acids to make the protein.
Amino acids are responsible for creating chains called peptides, which fold to become different proteins.
DNA → RNA → PROTEIN
This is the transfer of genetic instructions in DNA to mRNA. During transcription, a strand of mRNA is synthesized to complement a strand of DNA. This is done by understanding that certain bases will only match with certain chemicals.
Once the mRNA matures, it leaves the nucleus and moves to a ribosome, which consists of rRNA and proteins.
The ribosome reads the sequence of codons (set of 3 nucleotides) in mRNA and the molecules of tRNA will bring amino acids to the ribosome in the correct sequence.
With the help of rRNA, bonds will form between amino acids, creating a peptide chain, until a stop codon is read in the mRNA code. Once this step is completed, the protein can undergo additional processes to continue forming.
But why do proteins even matter?
Proteins do most of the work in our cells.
They’re important to the structure, function, and regulation of our body’s tissues and organs. They’re also responsible for hormone and enzyme production. An awesome protein function is protecting the body by binding to viruses. An example of a protein that helps keep us healthy is insulin.
The shape of a protein dictates it’s function, and the amino acids in the polypeptides that make up the protein will dictate its shape. When protein folding occurs, the amino acids in the chain will interact with each other to fold into a precise three-dimensional figure.
With all the new teh=chnology that’s coming out around “sequencing your genome” or “take a DNA test,” it really is important to understand what these companies are analyzing, so that you can make informed decisions.
Genomics is also insanely useful if you’re curious about better understanding yourself. If you want to understand your brain, the chemicals that produce emotions, the cells that make up your brain, all of that starts with 4 letters. A, T, C, and G.
A, T, C, G → Base pairs → DNA → RNA → Proteins → Us
- Our DNA writes our genetic code and acts as instructions to our cells
- DNA is sequences of nucleotides which are made up of 3 parts → a nitrogen base, a sugar group, a phosphate group
- Protein synthesis is the creation of proteins using 2 processes; transcription and translation
- mRNA is used in transcription as a messenger with all the details and instructions, while rRNA and tRNA build the protein using amino acids
- The amino acids interact with each other to fold the protein into a 3D shape that dictates its function
- Proteins are important for a ton of things in the body