TOM and TIM complexes.

Hello everyone, it's Staph here. 

Sorry I was away for a few days, thanks to the unstable internet connection :(

My internet for a few days was in it's full speed only at night, but that time I cannot blog because everyone sleeps at my home, and that's when I use internet for watching some....

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Come on I am young and you know what youngsters watch late night on internet :p

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Narutoooooooooooooooo!!!!!

Jeez! What were you thinking??

Jerk -_-

Anyways, it's two minute into the blog and I am off topic already.

Back to subject.

TOM and JERRY.

It's TOM and TIM.

Oh yeah.

TOM and TIM unlike you think are not puppies, neither they are cats, nor rats.

Sadly, TOM and TIM are mitochondrial multi-subunit complexes, duh.

They are protein translocators, and carry out protein translocation across the mitochondrial membranes;

TOM: Translocase for outer membrane.

TIM: For inner membrane. There are basically two types pf TIM known as dual TIM, nah just kidding.They are TIM 22 and TIM 23.

The TOM complex is required for the import of all nucleus-encoded mitochondrial proteins. It initially transports their signal sequences into the intermembrane space and helps to insert transmembrane proteins into the outer membrane. 

The TIM23 complex then transports some of these proteins into the matrix space, while helping to insert transmembrane proteins into the inner membrane. The TIM22 complex mediates the insertion of a subclass of inner membrane proteins, including the carrier protein that transports ADP, ATP, and phosphate. 

A third protein translocator in the inner mitochondrial membrane, the OXA complex, mediates the insertion of inner membrane proteins that are synthesized within the mitochondria. It also helps to insert some proteins that are initially transported into the matrix by the TOM and TIM complexes. 

It is thought that the TOM complex first transports the mitochondrial targeting signal across the outer membrane. Once it reaches in the intermembrane space, the targeting signal binds to a TIM complex, opening the channel in the complex through which the polypeptide chain either enters the matrix or inserts into the inner membrane. 

Although the functions of the TOM and TIM complexes are usually coupled to allow protein transport across both membranes at the same time, both protein types of translocator can work independently.

Here's a small diagram to show you the mechanism.
P.S.Do not draw this in the exam, your examiner might get cataract :p

Hope this helps.
-Staph <3
And always remember, that you are amazing :D