1. NUCLEIC ACIDS
Functions: store and transfer hereditary information (DNA and RNA), and act as energy intermediates (ATP).
The monomer of a nucleic acid is a nucleotide, which consists of a phosphate group, a 5-C sugar, and a nitrogen base. 1

2. NUCLEIC ACIDS Nucleotides link to form polymer strands of DNA or RNA.
The phosphate group of one nucleotide forms a covalent bond with the sugar of the next nucleotide. This is called a phosphodiester linkage. 2

3. Nitrogen-Containing Bases
There are two main types of nitrogen bases:
purines: Large, double ring molecules found in both DNA and RNA. 3

4. Nitrogen-Containing Bases
2. Pyrimidines – Smaller, single ring molecules found in DNA and/or RNA. 4

5. DNA and RNA Comparison DNA RNA Phosphate Group Deoxyribose Sugar
4 Possible N-bases: A, G, C, and T
4 Possible N- bases: A, G, C, and U
Phosphodiester bonds between nucleotides within strands
Phosphodiester bonds between nucleotides
Double Stranded: Two strands are bonded by hydrogen bonds between nitrogen bases.
Single Stranded 5

6. DNA Double Helix
Two DNA strands are joined together in a “double helix”. The nitrogen bases join together via hydrogen bonds:
A & T always join, forming
2 H Bonds.
C & G always join, forming
3 H Bonds. 6

7. DNA Double Helix
The strands run opposite to one another – they are said to run antiparallel to each other. 7

8. ATP – Adenosine Triphosphate
High-Energy Bonds
Composed of adenosine (adenine and ribose) and 3 phosphate groups.
The bonds between the phosphate groups contain a lot of energy. 8

9. ATP – Adenosine Triphosphate
ATP Hydrolysis: ATP + H2O  ADP + Pi KJ energy.
This is an exothermic reaction!
This is a reversible reaction:
ADP Condensation Reaction:
ADP + Pi + energy  ATP + H2O 9

11. ATP – Adenosine Triphosphate11