Nitrogenous bases are organic molecules that contain nitrogen and are essential components of nucleic acids (DNA and RNA). They are composed of carbon (C), hydrogen (H), oxygen (O), and nitrogen (N).

Here's a breakdown:

* Carbon (C): Forms the backbone of the molecule, providing a framework for the other atoms to attach.

* Hydrogen (H): Found in various positions throughout the molecule, contributing to its overall structure and bonding.

* Oxygen (O): Typically present in the form of carbonyl groups (C=O) or hydroxyl groups (OH), influencing the base's polarity and reactivity.

* Nitrogen (N): The defining element of nitrogenous bases, it plays a crucial role in hydrogen bonding between bases, which is essential for the structure and function of DNA and RNA.

Specific elements within each nitrogenous base:

There are five main nitrogenous bases:

* Adenine (A): C₅H₅N₅

* Guanine (G): C₅H₅N₅O

* Cytosine (C): C₄H₅N₃O

* Thymine (T): C₅H₆N₂O₂

* Uracil (U): C₄H₄N₂O₂

The specific arrangements of these elements and their bonding within each base contribute to their unique structures and interactions. For example, the presence of oxygen in guanine and thymine differentiates them from adenine and cytosine.

It's important to note that these are just the basic elements. The arrangement of atoms and the functional groups attached to them are what give each nitrogenous base its specific chemical and biological properties.