Complementary base pairing

[szeliga]

hey everyone, I'm looking for precise answer to this:

explain the importance of complementary base pairing in replication, transcription and translation.

i've been looking for exact answer and found only informations that don't fully answer it, or I'm not sure if they do.

thanks

[Sandwich]

Dunno if there's an official syllabus answer (check in your textbook!) but one obvious reason for complementary base pairing is to minimise errors. If a G and C pair and an A and T pair, and a G-T and G-A cannot pair (and so on) then you're going to have preferential pairing between correct bases as opposed to pairing between incorrect bases, thereby minimising error.

Given that you've got a system of error-free (in principle) matching, it therefore enables you to build DNA using a template manner where one strand will dictate the nature of the other strand. If a T could connect with an A, G or C, then you wouldn't be able to take one single strand of DNA and know which of those three matches. As matching is intrinsic to transcription, replication and translation (in translation amino acids each have a particular codon which they need to match) it follows that you'd be screwed in a system where you didn't have exact matching.

If a line of DNA that was ATTCG could be matched with any random combination, then you'd never be able to replicate it. However, because of complementary base pairing, then in replication (for instance) you know that you've got to synthesise the new strand so that it reads the opposite, i.e. the bases are matched and TAAGC. If you have a system that relies on a code, you have to be able to always apply the same rules to that code or you may as well not have a code at all! I hope that makes sense.