Here's a breakdown:
* DNA Structure: DNA is a double helix, meaning it consists of two long strands of nucleotides twisted around each other.
* Nucleotides: Each nucleotide is composed of a sugar (deoxyribose), a phosphate group, and a nitrogenous base.
* Nitrogenous Bases: There are four nitrogenous bases in DNA: Adenine (A), Thymine (T), Guanine (G), and Cytosine (C).
* Base Pairing: The two strands of DNA are held together by hydrogen bonds between the nitrogenous bases. Adenine (A) always pairs with Thymine (T), and Guanine (G) always pairs with Cytosine (C).
* Hydrogen Bonding: These bonds are relatively weak, but because they occur in large numbers along the length of the DNA molecule, they create a strong overall attraction between the two strands.
Important Note: While hydrogen bonds are the primary force holding the strands together, there are also phosphodiester bonds within each individual strand. These bonds link the sugar and phosphate groups of adjacent nucleotides, forming the sugar-phosphate backbone of the DNA molecule.
