Genes, Proteins, and DNA
The human body is made up of trillions of cells. Most recent estimates put the number of cells at approximately 30 trillion. (Written out, that’s 30,000,000,000,000) Cells are the building blocks of all living things — they have many different parts, each with different functions.
Each cell has a set of instructions for making us, like a recipe book for the body. This set of instructions is called our genome and is made up of deoxyribonucleic acids, DNA.
DNA is a long molecule that holds our unique genetic code. It contains the instructions for making all the proteins in our body. Each cell in the body has the same set of instructions, a copy of your genome made up of DNA. In fact, as you read this article, the cells in your body are dividing and the DNA in the cells is being copied.
There is a unique chemical code within DNA that guides our health and growth. This code is determined by the order of the four nucleotide bases that make up DNA. A nucleotide’s molecular structure is composed of a nitrogen-containing unit (base) linked to a sugar and a phosphate group.
The bases used in DNA are adenine (A), cytosine (G), guanine (G), and thymine (T).
Deoxyribose is the five-carbon sugar molecule that helps form the structure of the phosphate backbone. Attached to each sugar is one of four bases — A, C, G or T.
Lastly, the phosphate group in DNA serves as the backbone, the portion of the DNA double helix that provides structural support to the molecule.
The backbone is made of alternating sugar and phosphate groups.
All together, DNA forms a double helix shape, consisting of two strands that wind around each other. It’s structured like a twisted ladder.
The two strands are held together by bonds between the bases, with adenine forming a base pair with thymine, (A and T) and cytosine forming a base pair with guanine, (C and G.)