What would happen if we didn't have photosynthesis and cellular respiration?

1)Without photosynthesis: If we didn't have plants, algae and bacteria  to do the photosynthesis, CO2, a air pollutant wouldn't be converted in to glucose for those organisms and there would be no more Oxygen released to the atmosphere. Less photosynthesis  means less oxygen production and many organisms, like us, would die.
2)Without cellular respiration: Without this process we couldn't convert our food into the energy, ATP, necessary for the cells to function properly. Plus, this process also forms water, and without it, it would be another reason for the death of the cells.
Ultimately, will cause the death of the aerobic organism.