I understand that after the translation stage of ribosomal protein synthesis, tRNA molecules are floating in the cytoplasm without attached amino acids until they find the correct aminoacyl tRNA synthetase enzyme which revitalizes them.
However, in this process the enzyme takes an ATP molecule and returns an AMP (not ADP) molecule. It's been my understanding that an ATP's energy is normally harnessed via removing a single phosphate group and leaving an ADP molecule. Processes like respiration and photosynthesis deal with the conversion of ATP to ADP and vice versa. I understand that in removing the extra phosphate group to get an AMP more energy is released, but that also means that more energy has to be used to convert the AMP to ATP.
Does the cell convert the AMP to ADP, which will ultimately become ATP in respiration, or does the cell use some retrofitted respiration/metabolism to revitalize the AMP?
I would expect the first option but it would take energy (most likely from an ATP) and I would expect the amount of energy released from an ATP becoming an ADP to be different from the amount of energy released from an ADP becoming an AMP (so an ATP becoming an ADP would take more or less energy than would be required to make an AMP become an ADP, leading to inefficiencies). The other possibility (that I can see) is that the AMP is just used as a nucleotide in DNA and RNA, but I don't think that the numbers add up there. I've looked around but I can't find an answer.
So how do cells convert AMP to ATP? Also I was told that the ATP to ADP conversion is the general power-conversion. Is that not the case, or is this just some rare occurrence when AMPs are involved in power conversions?