DNA, the molecule that carries our genetic information, is shaped like a double helix. Imagine a twisted ladder – that's what a DNA molecule resembles. It's formed by two strands of nucleotides that wind around each other. The two strands are held together by bonds between the nitrogenous bases of each strand.
Here's a breakdown of its structure:
- Two Strands: DNA consists of two long chains of nucleotides, running in opposite directions.
- Nucleotides: Each nucleotide is made up of a sugar molecule, a phosphate group, and one of four nitrogenous bases: adenine (A), guanine (G), cytosine (C), and thymine (T).
- Base Pairing: Adenine always pairs with thymine (A-T), and guanine always pairs with cytosine (G-C). This pairing is crucial for maintaining the structure of the double helix.
- Twisted Ladder: The two strands twist around each other, forming a helical shape, resembling a twisted ladder.
While the double helix is the most common shape of DNA, it can take on other forms as well. These variations in shape can affect how DNA functions, such as how genes are turned on or off.
