Final answer:
Nucleic acids, encompassing both DNA and RNA, are biomolecules critical for genetic information storage, protein synthesis, and heredity. They are composed of chains of nucleotides with a sugar-phosphate backbone and sequence-specific nitrogenous bases.
Step-by-step explanation:
Nucleic Acids Definition and Role
Nucleic acids are essential biopolymers that are critical for storing and expressing genetic information in living organisms. These molecules include two main types: deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). Each nucleic acid strand is composed of monomers called nucleotides, which contain a five-carbon sugar, a phosphate group, and a nitrogenous base. Nucleotides connect via phosphate diester linkages, resulting in polynucleotide chains with directionality, indicated by a free 5' phosphate group and a free 3' hydroxyl group.
Specifically, DNA contains two polynucleotide chains forming a double helix, held together by bonds between complementary bases. It is the molecule that holds the genetic blueprint for protein synthesis and inheritance of traits. RNA, on the other hand, usually consists of a single polynucleotide chain and plays a role in protein synthesis as well as in various regulatory and catalytic activities within the cell.
By binding together, nucleotides form the backbone of nucleic acids, which in the case of DNA, creates its characteristic double helix shape. The sequence of nucleotides within nucleic acids encodes the genetic instructions vital for cellular functions such as cell division, protein synthesis, and the transmission of genetic information from one generation to the next.