* Nitrogenous Base: This is the unique part of the nucleotide and is what gives it its name. In DNA, the nitrogenous bases are adenine, guanine, cytosine, and thymine.
* Deoxyribose Sugar: This is a five-carbon sugar that forms the backbone of the DNA molecule.
* Phosphate Group: This is a negatively charged group that connects to the deoxyribose sugar and helps link nucleotides together to form the DNA chain.
Here's the function of each nucleotide:
1. Adenine (A):
* Pairs with Thymine (T): Adenine forms two hydrogen bonds with thymine, ensuring they always pair together in the DNA double helix.
* Role in DNA Replication: During replication, adenine serves as a template for the synthesis of new DNA strands, ensuring accurate copying of the genetic information.
2. Guanine (G):
* Pairs with Cytosine (C): Guanine forms three hydrogen bonds with cytosine, making this pairing stronger than the A-T pairing.
* Role in DNA Replication: Similar to adenine, guanine acts as a template during replication to ensure the correct sequence is copied.
3. Cytosine (C):
* Pairs with Guanine (G): Cytosine forms three hydrogen bonds with guanine, ensuring their pairing in the DNA double helix.
* Role in DNA Replication: Cytosine also serves as a template for the synthesis of new DNA strands during replication.
4. Thymine (T):
* Pairs with Adenine (A): Thymine forms two hydrogen bonds with adenine, maintaining the complementary pairing in DNA.
* Role in DNA Replication: Like the other nucleotides, thymine acts as a template during replication for the production of new DNA strands.
In summary, the four nucleotides in DNA (A, G, C, and T) work together to form the double helix structure, store genetic information, and ensure accurate replication of DNA during cell division.
