DNA - DEOXYRIBONUCLEIC ACID

DNA is the blueprint of life (has the instructions for making an organism)

established by James Watson and Francis Crick

---codes for your genes

---shape of a double helix

---made of repeating subunits called nucleotides

Gene - a segment of DNA that codes for a protein, which in turn codes for a trait (skin tone, eye color..etc), a gene is a stretch of DNA.

Nucleotide - consists of a sugar, phosphate and a base

Nucleotides (also called Bases)

Adenine, Thymine, , Guanine, Cytosine or A, T, G, C

Nucleotides pair in a specific way - called the Base-Pair Rule

Adenine pairs to Thymine

Guainine pairs to Cytosine

There is a double bond between A and T.

There is a tripple bond between C and G.

Memory helper - think "A T Granite City") - which is where you live

*The rungs of the ladder can occur in any order (as long as the base-pair rule is followed)

How the code works

For instance, a stretch of DNA could be AATGACCAT - which would code for a different gene than a stretch that read: GGGCCATAG.

Those 4 bases have endless combinations just like the letters of the alphabet can combine to make different words.

DNA REPLICATION

Replication is the process where DNA makes a copy of itself.

Why does DNA need to copy?

Cells divide for an organism to grow or reproduce, every new cell needs a copy of the DNA or instructions to know how to be a cell. DNA replicates right before a cell divides.

DNA replication is semi-conservative. That means that when it makes a copy, one half of the old strand is always kept in the new strand. This helps reduce the number of copy errors.