What is DNA and Genes? | Types, Definition, Structure, Function & Facts
What is DNA and Genes?
DNA is an essential molecule for life. It acts as a recipe containing instructions that tell our bodies how to grow and function.
What does DNA stand for?
DNA stands for deoxyribonucleic acid.
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What is DNA made of?
DNA is a long, thin molecule made up of something called a nucleotide. There are four different types of nucleotides: adenine, thymine, cytosine, and guanine. They are usually indicated by their first letter:
- A- adenine
- T- thymine
- C – cytosine
- G – guanine
Nucleotides are held together by a backbone made up of phosphate and deoxyribose. Nucleotides are sometimes referred to as “bases”.
Different Cells in the Body
Our body has about 210 different types of cells. Each cell does a different job to help our body function. There are blood cells, bone cells, and cells that make up our muscles.
How do Cells know what to do?
Cells get their instructions about what to do from DNA. DNA works like a computer program. A cell is a computer or hardware and DNA is a program or code.
The DNA Code
The DNA code is held by different letters of the nucleotides. As the cell “reads” the instructions on the DNA, different letters represent the instructions. All three letters make up a word called codon.
Although there are only four different letters, DNA molecules are thousands of letters long. This allows for billions and billions of different combinations.
Genes
Within each strand of DNA is a set of instructions called a gene. A gene that tells a cell how to make a particular protein. Proteins are used by cells to perform certain functions, to grow and to survive.
Shape of the DNA Molecule
Although DNA looks like long, thin wires under a microscope, it turns out that DNA has a specific shape. This shape is called a double helix. Outside the double helix is the backbone that holds the DNA together.
There are two sets of twisted dorsal spines. Between the skeletons are nucleotides represented by the letters A, T, C, and G. Another nucleotide connects to each backbone and then connects to another nucleotide in the center.
Only certain sets of nucleotides can match. You can think of them as puzzle pieces: A connects only to T and G only connects to C.
Interesting Facts about DNA
About 99.9% of the DNA of everyone on this planet is identical. It’s that 0.1% difference that makes us all unique.
The double helix structure of DNA was discovered by Drs James Watson and Francis Crick in 1953.
If you disassemble all the DNA molecules in your body and put them one after another, it will stretch towards the Sun and back again and again.
DNA is organized into structures called chromosomes in the cell.
DNA was first isolated and identified by Swiss biologist Friedrich Meischer in 1869.