Final answer:
The carbon and nitrogen atoms in purine bases are numbered according to a convention. The pentose sugar ring atoms are labeled with primed numbers, while the purine ring atoms are labeled with unprimed numbers.
Step-by-step explanation:
In purine bases, the carbon and nitrogen atoms are numbered according to a specific convention. The primed numbers (1', 2', 3', 4', and 5') designate the atoms of the pentose sugar ring, while the unprimed numbers (1, 2, 3, 4, 5, 6, 7, 8, and 9) designate the atoms of the purine ring. For example, in adenine, the carbons and nitrogen atoms are numbered as follows:
- 1' - Carbon of the pentose sugar
- 2' - Carbon of the pentose sugar
- 3' - Carbon of the pentose sugar
- 4' - Carbon of the pentose sugar
- 5' - Carbon of the pentose sugar
- 1 - Nitrogen of the purine ring
- 2 - Carbon of the purine ring
- 3 - Carbon of the purine ring
- 4 - Carbon of the purine ring
- 5 - Carbon of the purine ring
- 6 - Carbon of the purine ring
- 7 - Nitrogen of the purine ring
- 8 - Nitrogen of the purine ring
- 9 - Nitrogen of the purine ring