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.
1st stage, also known as the Krebs cycle, also know as the citric acid cycle
Motor neurons conduct nerve impulses from the central nervous system (brain and spinal cord) to an effector. A single motor neuron carries messages from the spinal cord to an effector. One or more interneurons in the spinal cord carry messages from a sensory neuron to a motor neuron.
