Protein synthesis is the process in which cells make proteins. It occurs in two stages: transcription and translation. Transcription is the transfer of genetic instructions in DNA to mRNA in the nucleus. It includes three steps: initiation, elongation, and termination
Oxytocin causes contractions during pregnancy, it also is the reason why mothers feel "motherly" towards their children after childbirth as there are high levels on oxytocin in the mother's blood.
Well, I cannot see your list of suggestions but I am assuming one of them would be muscles.
Muscles use a lot of energy and require a large number of mitochondria.