Nucleic acids

Definition

Nucleic acids are large biomolecules essential for all forms of life, primarily responsible for storing and transmitting genetic information. The two main types of nucleic acids are DNA (deoxyribonucleic acid) and RNA (ribonucleic acid), which serve different functions in the biological processes of organisms. They play a critical role in coding, decoding, regulation, and expression of genes, linking them to the building blocks of life and the structure and function of biological molecules.

5 Must Know Facts For Your Next Test

1. Nucleic acids are polymers made up of repeating units called nucleotides, which consist of a sugar, phosphate group, and nitrogenous base.
2. DNA contains the instructions for building proteins through the processes of transcription and translation facilitated by RNA.
3. The structure of DNA is characterized by its double helix formation, while RNA typically exists as a single strand.
4. Nucleic acids can also play roles in catalyzing biochemical reactions; for instance, some RNA molecules act as enzymes called ribozymes.
5. Mutations in nucleic acids can lead to changes in genetic information that may cause diseases or contribute to evolution.

Review Questions

• How do nucleic acids relate to the process of protein synthesis in living organisms?
  • Nucleic acids are directly involved in protein synthesis through the roles of DNA and RNA. DNA contains the genetic blueprint that codes for proteins. During transcription, segments of DNA are copied into messenger RNA (mRNA), which then transports this genetic information to ribosomes. At the ribosomes, transfer RNA (tRNA) translates the mRNA sequence into an amino acid chain, ultimately folding into functional proteins. Thus, nucleic acids are crucial for converting genetic information into the proteins that perform essential functions in cells.
• Compare and contrast the structures and functions of DNA and RNA.
  • DNA and RNA differ significantly in structure and function. DNA is double-stranded and has a deoxyribose sugar backbone with thymine as one of its four nitrogenous bases. Its primary function is to store genetic information. In contrast, RNA is typically single-stranded with ribose sugar and uses uracil instead of thymine. RNA's functions include acting as a messenger carrying instructions from DNA for controlling protein synthesis and sometimes serving catalytic roles in biochemical reactions. These structural differences lead to their distinct biological roles.
• Evaluate the significance of mutations in nucleic acids and their potential impact on evolutionary processes.
  • Mutations in nucleic acids are significant because they introduce variations in genetic sequences that can affect an organism's traits. Some mutations may be neutral or beneficial, potentially providing an advantage in survival or reproduction, thereby influencing natural selection. Over time, these beneficial mutations can accumulate within populations, leading to evolutionary change. Conversely, harmful mutations may decrease an organism's fitness or contribute to genetic diseases. Thus, mutations serve as a driving force in evolution by generating genetic diversity within populations.

Related terms

DNA: DNA is a double-stranded nucleic acid that carries genetic information necessary for the growth, development, and reproduction of all living organisms.

RNA: RNA is a single-stranded nucleic acid involved in various biological roles, including coding, decoding, regulation, and expression of genes.

nucleotide: A nucleotide is the basic building block of nucleic acids, composed of a sugar, a phosphate group, and a nitrogenous base.