There is an inherited syndrome in humans in which the cells cannot convert food into energy. some of the symptoms include muscle weakness and a lack of coordination. which malfunctioning organelle within the cell can cause this condition?

In this case, the affected organelle is the mitochondria. It is the central energy of the cell, it converts energetic molecules into ATP (the energy of the cell).
When there's a dysfunction in it, the energy production is decreased, so the subject will feel with muscles weakness, lack of coordination, short stature and cognitive delays...
This disease is inherited only from the mother because the transmission of the mitochondria is only maternal.