Genetics is the study of the variations between humans and how those variations are passed on through a family.
Our DNA is the basis of our genetics. DNA is the genetic code that acts as our body’s cookbook of recipes to tell it how to grow and develop. Our genetic code is very much the same, even among people who are not related. We share 99.9% of our DNA with each other!
Only 0.1% of our DNA is different from each other. However, it is this very small amount of difference that makes us unique. This means that we all share most of the information written in our cookbooks, but there are some variations in the recipes. Every cell of the human body (we have trillions of cells) contains our complete DNA genetic code. While DNA is very small, it contains a huge amount of information!
DNA is written in a 4 letter alphabet!
Our written alphabet has 26 letters. But the DNA alphabet is made up of only 4 letters: A, T, G, and C. These letters stand for the chemicals called nucleotides that make up the DNA molecule. A stands for adenine. T stands for thymine. G stands for guanine. C stands for cytosine. These four letters make up the entire 3 billion letters of the genetic code! The letters (A, T, C, and G) make up words as well, called codons. Unlike in our language, all words in the DNA recipe book are 3 letters long. For example, AGG, GAT, TAC, and CGG are all examples of codons. Our body is able to read these codons to make sense out of the DNA code. The codons all stand for different amino acids, which are the building blocks of the proteins in our bodies. For example, the codon GGC stands for an amino acid called glycine. There are 20 different amino acids that make up the proteins in our bodies.
What do proteins do?
Nearly everything! Proteins make up our skin, hair, internal organs, blood and bones. Our proteins are involved in nearly every process in our body including blood sugar regulation, food digestion and immune system function. There isn’t much that goes on in our bodies without the use of proteins.