Nucleic acids, like DNA and RNA, are vital for life, made up of nucleotides. These components—phosphate groups, sugars, and nitrogenous bases—play key roles in genetic coding, energy transfer, and the overall structure of biological molecules in bioengineering.
-
Nucleotides
- Building blocks of nucleic acids (DNA and RNA).
- Composed of a phosphate group, a pentose sugar, and a nitrogenous base.
- Serve as energy carriers (e.g., ATP) and signaling molecules.
-
Phosphate groups
- Essential for the formation of nucleotides and nucleic acids.
- Provide a negative charge, contributing to the overall structure and stability of DNA and RNA.
- Involved in energy transfer processes within cells.
-
Pentose sugars (ribose and deoxyribose)
- Ribose is found in RNA, while deoxyribose is found in DNA.
- The presence or absence of an oxygen atom distinguishes the two sugars.
- Sugar molecules form part of the nucleic acid backbone, linking nucleotides together.
-
Nitrogenous bases (adenine, guanine, cytosine, thymine, uracil)
- Four bases in DNA: adenine (A), guanine (G), cytosine (C), and thymine (T).
- RNA contains uracil (U) instead of thymine.
- Bases pair specifically (A with T, G with C in DNA; A with U, G with C in RNA) to form the genetic code.
-
Phosphodiester bonds
- Covalent bonds that link the phosphate group of one nucleotide to the sugar of another.
- Form the backbone of nucleic acids, providing structural integrity.
- Directionality is established (5' to 3' end) due to the nature of these bonds.
-
DNA double helix structure
- Composed of two antiparallel strands of nucleotides twisted around each other.
- Stabilized by hydrogen bonds between complementary nitrogenous bases.
- Major and minor grooves provide access for proteins to interact with the DNA.
-
RNA single-stranded structure
- Typically single-stranded, allowing for diverse shapes and functions.
- Can form secondary structures through base pairing within the same strand.
- Plays crucial roles in protein synthesis and gene regulation.
-
Base pairing rules
- A pairs with T (or U in RNA) and G pairs with C.
- Ensures accurate replication and transcription of genetic information.
- Base pairing is essential for the stability of the DNA double helix.
-
Nucleic acid backbone
- Composed of alternating sugar and phosphate groups.
- Provides structural support and defines the overall shape of the nucleic acid.
- The sequence of bases attached to the backbone encodes genetic information.
-
Major and minor grooves in DNA
- Formed by the twisting of the double helix, creating regions of accessibility.
- Major groove is wider and allows for protein binding and recognition.
- Minor groove is narrower but still plays a role in protein interactions and DNA stability.