Nucleic Acids
The information molecules — they store the body’s instructions and carry them out.
The two types
Section titled “The two types”- DNA (deoxyribonucleic acid) — the master archive, held in the cell nucleus; a double helix storing the complete set of genetic instructions.
- RNA (ribonucleic acid) — the working copy; several kinds carry instructions from DNA to the protein-building machinery and assist in building proteins.
Building blocks
Section titled “Building blocks”Both are chains of units called nucleotides, each carrying one of four “letter” bases. The sequence of bases is the code.
What they do
Section titled “What they do”- Storage — DNA preserves the instructions and is copied when cells divide.
- Expression — RNA transcribes a gene and translates it into a protein.
- Inheritance — DNA passes the instructions from parents to offspring.
Key idea
Section titled “Key idea”Nucleic acids are where the body’s information lives; the path from a DNA sequence to a working protein is the central thread of molecular biology. See the heredity root for more.