2. Nucleic Acids

3. Made from long strands of nucleotides (monomers)
Nucleic acids are large biomolecules (polymers) – essential for all known forms of life
Include DNA and RNA
Made from long strands of nucleotides (monomers)
A nucleotide contains a 5-carbon sugar, a phosphate group, and a nitrogenous base
The nitrogeneous bases are connected by the sugar and the phosphate group (rungs of the ladder)

4. DNA vs. RNA
If the sugar molecule is Deoxyribose, the nucleic acid is DNA
If the sugar molecule is Ribose, the nucleic acid is RNA
RNA – mRNA, tRNA, rRNA

5. Purines vs Pyrimidines
Purines have a 2-Carbon nitrogen ring base
Adenine
Guanine
Pyrimidines have a 1-carbon nitrogen ring base
Thymine
Cytosine

6. Nitrogeneous Bases Adenine Thymine (DNA only) Cytosine Guanine
Uracil (RNA only)

7. Base Pairing
The rules of base pairing (or nucleotide pairing) are: A with T: the purine adenine (A) always pairs with the pyrimidine thymine (T)
C with G: the pyrimidine cytosine (C) always pairs with the purine guanine (G)
The bases are paired with hydrogen bonds – 2 between A and T and 3 between C and G