In the field of molecular biology, the structure of DNA is of great importance. DNA consists of two strands that are held together by hydrogen bonds between complementary base pairs. Guanine (G) and cytosine (C) form a base pair through hydrogen bonding. Understanding the number of hydrogen bonds in the Guanine-Cytosine base pair is crucial in comprehending the stability and structure of DNA.


- Guanine and cytosine are two of the four nitrogenous bases found in DNA.
- Guanine is a purine base and cytosine is a pyrimidine base.
- In the DNA double helix, Guanine pairs with Cytosine.
- The Guanine-Cytosine base pair is formed through hydrogen bonding.


- Hydrogen bonds are weak chemical bonds that form between a hydrogen atom and an electronegative atom (oxygen, nitrogen, or fluorine).
- In the Guanine-Cytosine base pair, three hydrogen bonds are formed between the two bases.
- The hydrogen bonds are formed between the nitrogenous groups of Guanine and Cytosine.


- Guanine has an amino group (NH2) and a carbonyl group (C=O) in its structure.
- Cytosine also has an amino group (NH2) and a carbonyl group (C=O) in its structure.
- The amino group of Guanine forms a hydrogen bond with the carbonyl group of Cytosine, while the amino group of Cytosine forms a hydrogen bond with the carbonyl group of Guanine.
- Additionally, the carbonyl group of Guanine forms a hydrogen bond with the amino group of Cytosine, and the carbonyl group of Cytosine forms a hydrogen bond with the amino group of Guanine.


- The formation of three hydrogen bonds between Guanine and Cytosine contributes to the stability of the DNA double helix.
- The higher number of hydrogen bonds in the Guanine-Cytosine base pair compared to the Adenine-Thymine base pair (which forms two hydrogen bonds) enhances the strength of the DNA molecule.
- The specificity of base pairing through hydrogen bonding is crucial for the accurate replication and transmission of genetic information.

In conclusion, the Guanine-Cytosine base pair in DNA is held together by three hydrogen bonds. These hydrogen bonds contribute to the stability and structure of the DNA double helix.