All organisms need energy in order to survive. The most abundant form of energy on our planet is solar energy from the Sun. The trick is how to capture that solar energy and turn it into chemical energy that organisms can use.
The key is PHOTOSYNTHESIS!
Photosynthesis captures the solar energy and turns it into chemical energy in the form of glucose. But how do cells release that energy? CELLULAR RESPIRATION!
Photosynthesis and Cell Respiration
We do not need to completely understand the processes of photosynthesis and cell respiration. However, we do want to understand three things: 1) Photosynthesis is essential because it allows organisms to capture the abundant solar energy and turn it into chemical energy (glucose) 2) Cell respiration within cells allows the chemical energy in the glucose to be released and converted to ATP 3) These two processes form a cycle which produces byproducts which they each need. The diagram below shows how these two process work together.