Table of Contents
What is a Base Pair?
A base pair is a molecule composed of two nucleotides, which are the basic structural units of DNA and RNA. The nucleotides are composed of a nitrogenous base and a sugar molecule. The two nucleotides in a base pair are held together by hydrogen bonds between the nitrogenous base and the sugar molecule. There are four different nitrogenous bases in DNA and RNA: adenine (A), guanine (G), cytosine (C), and thymine (T). The sugar molecule in DNA is deoxyribose, and the sugar molecule in RNA is ribose.
Complementary Base Pairing
One of the most important principles of DNA is complementary base pairing. This principle states that adenine (A) pairs with thymine (T) and cytosine (C) pairs with guanine (G). This pairing is what allows the DNA molecule to form a double helix. The bases are held together by hydrogen bonds, which form between the nitrogen and oxygen atoms in the bases. These bonds are very strong and are resistant to breaking, which is why the DNA molecule is so stable.
About Base Pairing
A base pair is a pair of nucleotides in DNA or RNA that are hydrogen bonded to each other. The two nucleotides in a base pair are complementary, meaning that they have opposite charges and fit together like a lock and key. The base pairing rules dictate that A always pairs with T, and C always pairs with G. This ensures that the genetic information is accurately copied from one generation to the next.
Hydrogen Bonding and Stability
Hydrogen bonding is the attraction between a hydrogen atom and an atom of oxygen, nitrogen, or fluorine. This type of bonding is responsible for the high boiling point of water, and the fact that water is a liquid at room temperature. The hydrogen atom in a hydrogen bond is covalently bonded to an atom of oxygen, nitrogen, or fluorine, and the electron in the hydrogen atom’s covalent bond is shared with the electron in the oxygen, nitrogen, or fluorine atom’s covalent bond. This sharing of electrons creates a partial positive charge on the hydrogen atom and a partial negative charge on the atom of oxygen, nitrogen, or fluorine. These partial charges create an electrostatic attraction between the hydrogen atom and the atom of oxygen, nitrogen, or fluorine, and this attraction is responsible for the hydrogen bond.
The strength of a hydrogen bond is affected by the electronegativity of the atoms involved in the bond. The greater the difference in electronegativity between the two atoms, the stronger the hydrogen bond. Hydrogen bonds are also stronger when the hydrogen atom is attached to an atom of oxygen, nitrogen, or fluorine that is in a more electronegative position than the hydrogen atom.
