ATP transport throughout the cell?

[mattw]

We know that ATP is created in the mitochondrial matrix by adding a phosphate group to ADP. This is done by the ATP synthases embedded in the inner mitochondrial membrane. But what about the energy needs of the rest of the cell's metabolism outside the mitochondria? So, two questions:

(1)Don't the mitochondria have to export most of the ATP they make, and import much ADP from all other parts of the cell?

(2)These are fairly large molecules --how are they transported across membranes?

[MrMistery]

1. Yes
2. They're not so large, they can easily pass through channel proteins in the inner mitochondrial membrane...

[Mr Joe]

i understand the MAIN concept of ADP but where does it come from and where does it go...........or does it just wait around after ATP is used and wait on a phosphate to turn it into ATP again...........like i said i dont understand ADP

[Caspase]

ADP = ATP - a Phosphate

So they are nearly the same thing except ADP has less chemical energy.

ATP is created in cells via redox reactions know as cellular respiration. Examples are glycolysis, the citric acid cycle, and beta-oxidation.

[Mr Joe]

after mitochondria creates ATP and ATP loses the phosphate and becomes ADP, does ADP go back to the mitochondria to get the phosphate that it lost ?
i guess my question is what happens to ADP? where does it go to get the phosphate that it lost, or does it go somewhere else in the cell as ADP to be used for another process?

[Caspase]

Chloroplasts, mitochondria, cytosol, and glycosomes are areas that can create ATP. (hey guys tell me if I missed one) ADP can be further broken down to AMP. Any ATPases can do this. ATPsynthase is an enzyme that can make ATP from ADP by adding P. ATPsynthase is present in mitochondria, chloroplasts, and i'm not sure where else. I don't know why ATPsynthase can't be in the cytosol and glycosomes.

[Mr Joe]

thank you, that was exactly what i was looking for
whats AMP used for?

[MrMistery]

in its cyclical form, cAMP is one of the most important second messengers in the cell. In it's linear form, the only role it has is regulation(it serves as a signal for turning pathways on and off).