Final answer:
Photosynthesis is a process that requires sunlight, carbon dioxide, and water to produce oxygen and carbohydrate molecules. These sugar molecules contain energy that living things need to survive.
Step-by-step explanation:
Photosynthesis is a multi-step process that requires sunlight, carbon dioxide, and water as substrates. After the process is complete, it releases oxygen and produces glyceraldehyde-3-phosphate (G3P), simple carbohydrate molecules that can subsequently be converted into glucose or other sugar molecules. These sugar molecules contain energy and the energized carbon that all living things need to survive.