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.

The soviet union beat the us to the first successful launch, with the october 4, 1957, orbiting of sputnik 1, and later beat the us to have the first human in earth orbit, yuri gagarin, on april 12, 1961. the "race" peaked with the july 20, 1969, us landing of the first humans on the moon with apollo 11

Answer:

it provides an alternative energy pathway for the reaction to proceed.

explanation:

a catalyst is a substance that speeds up the rate of a chemical reaction but is not consumed during the course of the reaction.

catalysts increase the rate of reaction without being used up. they do this by lowering the activation energy needed. with a catalyst, more collisions result in a reaction, so the rate of reaction increases. different reactions need different catalysts.

a catalyst works by providing an alternative reaction pathway to the reaction product. the rate of the reaction is increased as this alternative route has a lower activation energy than the reaction route not mediated by the catalyst.