What do you mean by antiparallel nature of two DNA chains ?

Explanation

To understand the antiparallel nature of DNA chains, we need to break down the concept step by step:

### Step 1: Structure of DNA
DNA is composed of two strands that form a double helix. Each strand is made up of nucleotides, which are the building blocks of DNA.

### Step 2: Directionality of DNA Strands
Each DNA strand has a directionality based on the orientation of its sugar molecules. The two ends of a DNA strand are referred to as the 5' (five-prime) end and the 3' (three-prime) end. The 5' end has a phosphate group attached to the fifth carbon of the sugar, while the 3' end has a hydroxyl (OH) group attached to the third carbon.

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