Discuss on Nucleic acid structures and compositions. Provide information about 4 pages

Answer 1

Nucleic acids are the molecules responsible for carrying and transmitting genetic information in all living organisms. There are two main types of nucleic acids: deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). Both DNA and RNA are long chains of nucleotides, which are composed of a sugar (deoxyribose in DNA, ribose in RNA), a phosphate group, and a nitrogenous base.

The structure of nucleic acids is often referred to as a double helix, in the case of DNA, or a single strand with secondary structures, such as hairpin loops and stem-loop structures, in the case of RNA. The double helix of DNA consists of two polynucleotide chains running in opposite directions, with the nitrogenous bases on one chain pairing with complementary bases on the other chain through hydrogen bonding. Adenine pairs with thymine (or uracil in RNA), and cytosine pairs with guanine. This base pairing allows DNA to replicate faithfully and ensures the transmission of genetic information from one generation to the next.

In addition to the primary structure of nucleic acids, the secondary and tertiary structures are crucial for their functions. RNA molecules can form complex three-dimensional structures through base pairing interactions, leading to the formation of functional regions such as binding sites for proteins or catalytic centers for enzymatic activity. In contrast, DNA is typically found in a more linear, double-stranded form, with the major function of storing genetic information.

The composition of nucleic acids is determined by the sequence of nucleotides that make up the molecule. The specific sequence of nucleotides in a gene determines the amino acid sequence of the protein it encodes, and ultimately the function of that protein. Changes in the nucleotide sequence, known as mutations, can lead to alterations in the protein structure and function, causing genetic disorders or diseases.

In addition to their role in storing genetic information, nucleic acids also play important roles in gene expression and regulation. RNA molecules are involved in several essential processes, including transcription, translation, and splicing. Small RNA molecules, such as microRNAs and small interfering RNAs, also regulate gene expression by targeting specific messenger RNA molecules for degradation or inhibiting their translation.

Overall, the structure and composition of nucleic acids are fundamental to their functions in storing and transmitting genetic information, as well as in regulating gene expression. Understanding the intricate structures and compositions of nucleic acids is essential for unraveling the complexity of biological processes and genetics.