Which biomolecule contains nitrogenous bases?
a. Nucleic acids
b. Lipids
c. Carbohydrates
d. Proteins
The Correct Answer and Explanation is :
The correct answer is: a. Nucleic acids
Explanation
Nucleic acids, including DNA (deoxyribonucleic acid) and RNA (ribonucleic acid), are biomolecules that contain nitrogenous bases. These bases are integral to the structure and function of nucleic acids. There are four primary nitrogenous bases in DNA: adenine (A), thymine (T), cytosine (C), and guanine (G). RNA also has adenine, cytosine, and guanine, but replaces thymine with uracil (U). These nitrogenous bases play a key role in storing and transmitting genetic information.
The structure of nucleic acids consists of repeating units called nucleotides, each made up of three components: a nitrogenous base, a sugar molecule (deoxyribose in DNA and ribose in RNA), and a phosphate group. The nitrogenous bases are divided into two categories: purines (adenine and guanine) and pyrimidines (cytosine, thymine, and uracil). In DNA, the bases pair in a complementary manner, with adenine pairing with thymine and cytosine with guanine. This complementary pairing, through hydrogen bonds, creates the characteristic double helix structure of DNA.
Nucleic acids are essential for all living organisms because they store genetic information, which guides the synthesis of proteins. Through the processes of transcription and translation, RNA helps decode DNA instructions to create specific proteins. These proteins are critical for cellular function and structure, influencing everything from enzyme activity to the physical characteristics of an organism.
In contrast, lipids and carbohydrates primarily serve as energy storage molecules and structural components, lacking nitrogenous bases in their structures. Proteins do contain nitrogen in the form of amino groups but lack the specific nitrogenous bases that are unique to nucleic acids.