DNA

Nucleic Acids

Informational polymers Made of C,H,O,N and P No general formula Examples: DNA and RNA

DNA Deoxyribonucleic Acid. Makes up genes. Genetic information for life.

RNA

Ribonucleic Acid. Structure and protein synthesis. Genetic information for a few

viruses only.

Nucleic Acids

Polymers of nucleotides Nucleotides have three parts:

nitrogenous base pentose sugar phosphate

Nitrogenous Bases

Rings of C and N Two types:

Pyrimidines (single ring) Purines (double ring)

Four bases in DNA

Adenine- A Thymine- T Cytosine- C Guanine- G

Four bases in RNA

Adenine- A Uracil- U Cytosine- C Guanine- G

Nitrogenous Bases A & G=

purines C & T & U=

pyrimidines Each purine

binds with a pyrimidine

Nitrogenous Bases Hydrogen

bonds differ A&T= 2

bonds C&G= 3

bonds

Complimentary Bases

Bases that pair together during building and replication of DNA

A is complementary to T G is complementary to C

Pentose Sugar

5-C sugar Ribose - RNA Deoxyribose – DNA RNA and DNA differ in a –OH group

on the 2nd carbon.

Phosphate

PO4 – Overall negative molecule Makes DNA a negative molecule

Sugar-Phosphate Backbone

Makes up the outside backbones of DNA and RNA

Alternating sugars and phosphates

Complimentary bases

If 44% of the DNA is Guanine, what percentage is

Cytosine? Adenine? Thymine?

DNA replication

Binding of enzymes to existing DNA (DNA polymerase)

Unwinding of the double helix Synthesis of a new matching

strand for each side of the original DNA

End up with 2 identical strands