Cell structure Animal cells and plant cells have certain structures in common. Structure Function Cytoplasm Where most of the chemical reactions happen Nucleus Contains genetic material which controls the cell’s activities Cell membrane Controls the movement of substances in and out of the cell Mitochondria Where most energy is released in respiration Ribosomes Where protein synthesis happens Plant cells have additional structures. Structure Function Chloroplasts Absorb light energy for photosynthesis Cell wall Strengthens the cell and supports the plant Permanent vacuole Filled with cell sap to help keep the cell swollen Animal cells may also have vacuoles, but these are small and temporary.