Describe the properties and major functions of Nucleic acids

Answer 1

Nucleic acids are macromolecules that store and transmit genetic information in living organisms. There are two types of nucleic acids: deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). Here are the properties and major functions of nucleic acids:

Properties:
1. Polynucleotide Structure: Nucleic acids are composed of long chains of nucleotides bonded together. Each nucleotide consists of a phosphate group, a sugar molecule (either deoxyribose or ribose), and a nitrogenous base (adenine, thymine/uracil, cytosine, or guanine).

2. Double Helix Structure (DNA): DNA exists as a double-stranded helix, with two strands of nucleotides twisted around each other. The strands are held together by hydrogen bonds between complementary nitrogenous bases.

3. Single-stranded Structure (RNA): RNA is usually single-stranded, but it can fold upon itself to form intricate three-dimensional structures due to base pairing between complementary regions.

4. Nitrogenous Bases: The four nitrogenous bases in DNA are adenine (A), thymine (T), cytosine (C), and guanine (G). In RNA, thymine is replaced by uracil (U). The order and sequence of these bases encode genetic information.

Major Functions:
1. Storage of Genetic Information: The primary function of nucleic acids is to store genetic information. In DNA, this information is in the form of genes which contain instructions for building and maintaining an organism. The order of nitrogenous bases in DNA, known as the genetic code, determines the sequence of amino acids in proteins.

2. Replication: DNA undergoes replication, a process by which the genetic information is duplicated before cell division. During replication, the DNA strands unwind and serve as templates for the synthesis of new complementary strands, resulting in two identical DNA molecules.

3. Transcription: DNA is transcribed into RNA in a process called transcription. During transcription, the DNA sequence in a gene is copied into a complementary RNA molecule. This RNA molecule, known as messenger RNA (mRNA), carries the instructions from the DNA to the protein synthesis machinery in the cell.

4. Translation: RNA participates in translation, the process in which proteins are synthesized. During translation, mRNA is decoded by ribosomes, and the sequence of codons (sets of three bases) determines the order of amino acids in a polypeptide chain, forming a protein.

5. Regulation of Gene Expression: Nucleic acids, especially RNA, play a critical role in regulating gene expression. Various types of regulatory RNAs control the timing, location, and amount of gene expression, ensuring the correct functioning and development of an organism.

Overall, nucleic acids are crucial molecules not only for storing and transmitting genetic information but also for controlling and directing various cellular processes.