DNA and Mitotic Cell Cycle CRAM

Complementary Base Pairs in DNA

• Definition: Complementary base pairs are the pairs of nitrogenous bases in DNA that bond together.

• Base Pairing Rules:

  • Adenine (A) pairs with Thymine (T)

  • Cytosine (C) pairs with Guanine (G)

• Importance: These pairs ensure accurate DNA replication and information transfer.

Structure of a Nucleotide

• Components: Every nucleotide consists of three main parts:

  • Phosphate Group: A phosphorus atom bonded to four oxygen atoms.

  • Pentose Sugar: A five-carbon sugar molecule.

    • For DNA: The sugar is deoxyribose.

    • For RNA: (not mentioned in detail but should note that it is ribose)

  • Nitrogenous Base: One of the four bases (A, T, C, or G for DNA).

Summary of Nucleotide Structure in DNA

• Nucleotide Composition in DNA:

  • Phosphate group

  • Deoxyribose sugar

  • Nitrogenous Bases: Adenine (A), Thymine (T), Cytosine (C), Guanine (G)

• Utilization: Nucleotides serve as the building blocks of nucleic acids, forming the genetic code.