Nucleic acids

Definition

Nucleic acids are large biomolecules essential for all known forms of life, primarily serving as the carriers of genetic information. They consist of long chains of nucleotide units, which are the building blocks that include a sugar, a phosphate group, and a nitrogenous base. The two main types of nucleic acids, DNA and RNA, play crucial roles in the storage, transmission, and expression of genetic information within cells.

5 Must Know Facts For Your Next Test

1. Nucleic acids are categorized into two main types: DNA (double-stranded) and RNA (single-stranded), each serving different functions within biological systems.
2. The sequence of nitrogenous bases in nucleic acids encodes genetic information, with specific sequences determining traits and characteristics in organisms.
3. Nucleic acids can undergo processes such as replication (for DNA) and transcription (for RNA), which are essential for cellular function and heredity.
4. In addition to their role in genetics, nucleic acids are also involved in regulating biological processes through RNA molecules like miRNA and siRNA.
5. Nucleic acids are synthesized in the nucleus of eukaryotic cells, and their functions extend beyond genetics to include roles in metabolism and cellular signaling.

Review Questions

• How do the structures of DNA and RNA differ, and what implications do these differences have for their functions in living organisms?
  • DNA is typically double-stranded with a helical structure, providing stability and allowing it to store genetic information long-term. In contrast, RNA is usually single-stranded, which enables it to fold into various shapes for different functions, including acting as a messenger for protein synthesis. These structural differences mean that DNA serves primarily as the genetic blueprint, while RNA plays active roles in translating that information into functional proteins.
• Discuss the process of transcription in relation to nucleic acids and its importance in gene expression.
  • Transcription is the process by which the genetic information encoded in DNA is copied into messenger RNA (mRNA). During transcription, RNA polymerase binds to a specific region of the DNA and synthesizes a complementary RNA strand. This mRNA then carries the genetic code from the nucleus to the ribosomes, where it guides protein synthesis. This process is crucial because it enables genes to be expressed as proteins, allowing cells to function according to their specific roles.
• Evaluate the impact of mutations in nucleic acids on protein synthesis and overall cellular function.
  • Mutations in nucleic acids can lead to changes in the sequence of nucleotides that make up genes. These changes can result in altered mRNA transcripts during transcription, which may produce dysfunctional or nonfunctional proteins during translation. Such mutations can disrupt normal cellular processes and lead to diseases or developmental issues. Evaluating how these mutations affect protein synthesis helps scientists understand disease mechanisms and develop targeted therapies.

Related terms

DNA: Deoxyribonucleic acid (DNA) is the molecule that carries genetic instructions for the development, functioning, growth, and reproduction of all known living organisms and many viruses.

RNA: Ribonucleic acid (RNA) is a single-stranded molecule involved in protein synthesis and gene regulation, acting as a messenger carrying instructions from DNA for controlling the synthesis of proteins.

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