1. No credible source
2. Check if its a biased answer
3. Examine evidence
There are more than 5 factors, but here are perhaps the most important ones:
1) Light: Light energy is a crucial component in photosynthesis, as it is the primary energy source of the process.
2) Carbon Dioxide: Another key ingredient in photosynthesis.
3) Temperature: There is an optimum temperature for photosynthesis that varies from organism to organism. Too cold or two hot, and rate of photosynthesis will be lower.
4) Water - Like almost all life process, water is a key component in photosynthesis.
5) Oxygen. A common misconception is that plants only "breathe in" carbon dioxide and expel oxygen. Plant cells actually require oxygen as well in order to function, and thus oxygen is a necessary part of photosynthesis.
Cyanobacteria don't need oxygen to survive they produce oxygen. They where the first ever known organisms on the planet and they produced oxygen in the oceans which was absorbed by iron deposits and then once the iron had oxygen the ocean got the oxygen until it got into the atmosphere and Eukaryota bacteria evolved. So the answer would be: <span>They convert nitrates from the water into nitrogen gas (N2) that is released into the atmosphere.</span>
Molecules that cannot cross the membrane bind to receptors in the membrane. When the signal binds to a receptor changes it's shape. Other Molecules inside the cell respond to the chainging shape of the receptor.