a. What are the four major heterocyclic bases in DNA?

Verified step by step guidance

1. Identify the four major heterocyclic bases in DNA, which are also known as nucleobases.
2. Recall that these bases are divided into two categories: purines and pyrimidines.
3. Understand that the purines in DNA are adenine (A) and guanine (G).
4. Recognize that the pyrimidines in DNA are cytosine (C) and thymine (T).
5. Summarize that the four major heterocyclic bases in DNA are adenine (A), guanine (G), cytosine (C), and thymine (T).

Key Concepts

Heterocyclic Bases

Heterocyclic bases are nitrogen-containing compounds that form the building blocks of nucleic acids like DNA and RNA. In DNA, these bases are crucial for encoding genetic information and consist of purines and pyrimidines, which are types of heterocycles. Understanding their structure and function is essential for grasping how genetic information is stored and transmitted.

Purines and Pyrimidines

Purines and pyrimidines are two categories of nitrogenous bases found in DNA. Purines include adenine (A) and guanine (G), while pyrimidines consist of cytosine (C) and thymine (T). The specific pairing of these bases (A with T and C with G) is fundamental to the double-helix structure of DNA and is critical for processes like DNA replication and transcription.

Base Pairing

Base pairing refers to the specific hydrogen bonding between complementary nitrogenous bases in DNA. This pairing is essential for maintaining the stability of the DNA double helix and ensuring accurate replication and transcription. The rules of base pairing (A-T and C-G) are foundational to molecular biology and genetics, influencing how genetic information is expressed and inherited.