P Site and A site's in translation

[SundevilDMD]

Anybody have a good explanation for what the P site and A site is in translation?

Any help would be appreciated

Thanks

sundevil

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[JohnDoeDDS]

okay so the tRNA comes in to the A site with its amino acids, and the mRNA tells the ribosomes which AA it needs basically so that AA from the tRNA gets added on to the polypeptide chain at the P site. Once the translation is complete you have a fully functional (hopefully) protein that comes from the P site.

 

[Notoriousjae]

Anybody have a good explanation for what the P site and A site is in translation?

Any help would be appreciated

Thanks

sundevil

The ribosome consists of three sites: the A site, the P site, and the E site. The A site in the point of entry for the amino acetyl tRNA. The P site is where the peptidyl tRNA enters the ribosome. And the E site is a site briefly occupied by the growing peptide chain as it exits the ribosome.

for a more detailed explanation find a genetics textbook.

 

[Immuno-guy]

The letters are the easiest way to remember this one:

the A site is for the addition of the AminoAcyl group

the P site is for the nascent PolyPeptide chain.


Good luck.

 

[dancedancekj]

Edit

 

[tinman831]

Doesn't the first AA in the chain (met) go into the P site and the subsequent ones go into the A?

 

[Resonance]

Doesn't the first AA in the chain (met) go into the P site and the subsequent ones go into the A?

That is correct the intiator tRNA binds at the P site.

 

[ConfusedOne]

is the growing polypeptide added to the amino acid in the A site? Thanks

 

[JohnDoeDDS]

no the growing is added to the E site.

Bit I thought that the intitator binds to the P site, no?

 

[tinman831]

no the growing is added to the E site.

Bit I thought that the intitator binds to the P site, no?

All incoming AA's are added at the A site. The E site is where the chain exits.

 

[Resonance]

All incoming AA's are added at the A site. The E site is where the chain exits.

Actually, the uncharged tRNAs exit from the E site. During termination the polypeptide chain is cleaved from the tRNA in the P site and released.

 

[armorshell]

Can anyone tell me where exactly on the ribosome the G spot is? I keep hearing about it but it's really hard to find...

 

[tom_servo_dds]

Anybody have a good explanation for what the P site and A site is in translation?

Any help would be appreciated

Thanks

sundevil

Hope this helps for a reference:
http://en.wikipedia.org/wiki/Translation_(genetics)#Prokaryotic_translation

 

[bluesdeluxe]

Finding the G spot on the ribosome shouldn't be hard to locate at all really but you shouldn't need to find it at all for the DAT, they don't test you on that....I'd just focus on what you need to do well. Otherwise, if you are looking down the ribosome it is down a bit and up top. Good luck with your test 😉