Identify each of the following bases as a pyrimidine or a purine:


e. guanine

Verified step by step guidance

1. Identify the two categories of nitrogenous bases in nucleic acids: purines and pyrimidines.
2. Recall that purines have a two-ring structure, while pyrimidines have a single-ring structure.
3. List the common purines: adenine (A) and guanine (G).
4. List the common pyrimidines: cytosine (C), thymine (T), and uracil (U).
5. Determine that guanine is a purine because it is one of the bases with a two-ring structure.

Key Concepts

Pyrimidines and Purines

Pyrimidines and purines are the two categories of nitrogenous bases found in nucleic acids. Pyrimidines, which include cytosine, thymine, and uracil, have a single six-membered ring structure. In contrast, purines, such as adenine and guanine, consist of a fused double-ring structure, which includes a six-membered and a five-membered ring. Understanding these classifications is essential for identifying the structure and function of nucleotides in DNA and RNA.

Guanine

Guanine is one of the five primary nucleobases in the genetic code and is classified as a purine. It plays a critical role in the structure of DNA and RNA, pairing with cytosine in DNA and RNA molecules. Guanine is also involved in various cellular processes, including energy transfer and signaling, due to its role in forming guanosine triphosphate (GTP). Recognizing guanine's classification helps in understanding its biochemical functions and interactions.

Base Pairing

Base pairing refers to the specific hydrogen bonding between nitrogenous bases in nucleic acids, which is fundamental to the structure of DNA and RNA. In DNA, adenine pairs with thymine, while guanine pairs with cytosine. This complementary pairing is crucial for the accurate replication and transcription of genetic information. Understanding base pairing is essential for grasping how genetic information is stored and transmitted in living organisms.