Here's a breakdown:
* Two strands: The DNA molecule consists of two long strands of nucleotides.
* Nucleotides: Each nucleotide is made up of a sugar molecule (deoxyribose), a phosphate group, and one of four nitrogenous bases: adenine (A), guanine (G), cytosine (C), and thymine (T).
* Base pairing: The two strands are held together by hydrogen bonds between the bases. Adenine always pairs with thymine (A-T), and guanine always pairs with cytosine (G-C).
* Helix: The two strands twist around each other, forming a helical structure. This twisting gives the DNA molecule its characteristic double helix shape.
Think of a spiral staircase, with the sides of the staircase representing the sugar-phosphate backbone of each strand and the steps representing the base pairs.
