Polynucleotide

Definition

A polynucleotide is a large biomolecule composed of multiple nucleotides linked together in a long, continuous chain. Polynucleotides are the fundamental building blocks of nucleic acids, such as DNA and RNA, which store and transmit genetic information within living organisms.

5 Must Know Facts For Your Next Test

1. Polynucleotides are the primary components of DNA and RNA, which are essential for the storage, transmission, and expression of genetic information in living organisms.
2. The sequence of nucleotides in a polynucleotide chain determines the genetic code and the specific instructions for the synthesis of proteins and other biomolecules.
3. DNA polynucleotides are composed of deoxyribonucleotides, while RNA polynucleotides are composed of ribonucleotides, with the primary difference being the type of sugar present in the nucleotide structure.
4. Polynucleotides can form secondary and tertiary structures, such as the famous double-helix structure of DNA, which is crucial for the proper function and stability of these biomolecules.
5. The length and sequence of a polynucleotide chain can vary greatly, with some DNA molecules containing millions of nucleotides and playing a vital role in the genetic makeup of an organism.

Review Questions

• Explain the relationship between polynucleotides and nucleic acids, and describe their role in the storage and transmission of genetic information.
  • Polynucleotides are the fundamental building blocks of nucleic acids, such as DNA and RNA, which are responsible for storing and transmitting genetic information within living organisms. The sequence of nucleotides in a polynucleotide chain encodes the genetic code, providing the instructions for the synthesis of proteins and other essential biomolecules. This genetic information is passed down from one generation to the next, ensuring the continuity and diversity of life.
• Discuss the structural differences between DNA and RNA polynucleotides and how these differences contribute to their unique functions.
  • DNA and RNA polynucleotides differ in the type of sugar present in their nucleotide structure. DNA polynucleotides are composed of deoxyribonucleotides, which contain a deoxyribose sugar, while RNA polynucleotides are composed of ribonucleotides, which contain a ribose sugar. These structural differences result in distinct properties and functions for the two types of nucleic acids. DNA is primarily responsible for the long-term storage and transmission of genetic information, while RNA plays a crucial role in the expression of genetic information, acting as a messenger, adapter, and catalyst in various cellular processes.
• Analyze the importance of the secondary and tertiary structures of polynucleotides, such as the DNA double helix, in the stability and function of these biomolecules.
  • The secondary and tertiary structures of polynucleotides, such as the iconic double-helix structure of DNA, are essential for the stability and proper function of these biomolecules. The double-helix structure of DNA, formed through the base pairing of complementary nucleotides, provides stability and protection for the genetic information stored within the polynucleotide chain. Additionally, the higher-order structures of polynucleotides, including hairpin loops, stem-loops, and more complex tertiary folds, are crucial for the diverse functions of nucleic acids, such as regulating gene expression, facilitating enzymatic reactions, and enabling the proper folding and function of RNA molecules. These structural features contribute to the overall stability, flexibility, and functional versatility of polynucleotides in living organisms.

Related terms

Nucleotide: The basic structural unit of a polynucleotide, consisting of a nitrogenous base (adenine, guanine, cytosine, or thymine/uracil), a sugar (deoxyribose or ribose), and a phosphate group.

Nucleic Acid: A large biomolecule, such as DNA or RNA, that is composed of long chains of polynucleotides and serves as the primary carrier of genetic information in living organisms.

Monomer: The smallest repeating unit that makes up a larger polymer, such as a nucleotide in a polynucleotide chain.