DNA!

spooled

chromosomes

chromatindouble helix

gene

Watson Crick

Wilkins Franklin

1953

Nucleotides are the monomer of nucleic acids

This component varies

The chain of nucleotides creates a nucleic acid, a polymer

nucleotide

sugar

phosphate

N-base

covalent bondH-bond

base pairs

DNA has 4 nucleotides

purines pyrimidines

The base pair rule makes the two helices complementary

Adenine bonds to Thymine

Cytosine bonds to Guanine

DNA is replicated when cells reproduce (mitosis, meiosis)

• each old strand acts as a template for a new one • the two stands each contain half of the original

Thus replication is semi-conservative

http://www.wiley.com/college/pratt/0471393878/student/animations/dna_replication/

RNA is a nucleic acid with a slightly different structure

*

Single helix

uracil pairs with adenine during RNA synthesis

Ribose sugar vs deoxyribose of DNA

RNArewrites and interprets the code

multiple types of RNA

DNA segments of the sequence - genes - code for proteins

Function of each differs, but are complementary