how does the structure of DNA help account for the way in wich DNA copies itself

http://www.youtube.com/watch?v=5VefaI0LrgE

The structure of DNA, specifically its double helix shape, plays a crucial role in the process of DNA replication. Let's break it down to understand how the structure aids in DNA copying itself.

1. Double Helix: DNA is made up of two strands that wind around each other in a spiral staircase-like structure, forming a double helix. Each strand consists of a sugar-phosphate backbone with attached nucleotide bases. The base pairs (adenine with thymine and cytosine with guanine) connect the two strands, creating the rungs of the DNA ladder.

2. Complementary Base Pairing: The base pairing rules state that adenine (A) always pairs with thymine (T), and cytosine (C) always pairs with guanine (G). This complementary base pairing is essential because it allows for precise replication of the DNA.

3. DNA Replication Process: When DNA replicates, the double helix unwinds, separating the two strands. Each strand then acts as a template for the formation of a new complementary strand.

- Enzymes called DNA helicases unwind and open up the double helix by breaking the hydrogen bonds between the base pairs.

- DNA polymerase enzymes move along each separated DNA strand, adding the complementary nucleotides according to the base pairing rules. For example, if the original strand has the sequence ATGCC, the new strand would have the complementary sequence TACGG.

4. Semi-conservative Replication: The way DNA replicates is known as semi-conservative replication, meaning that each new DNA molecule consists of one original strand (template) and one newly synthesized strand.

The structure of DNA allows for accurate and efficient copying because the complementary base pairing ensures that each new strand is an exact match to the original strand. This fidelity ensures that genetic information is faithfully transmitted to the next generation.