Question

What is one component in photosynthesis that is not recycled and must be constantly available?

Answer 1

The ultimate source of energy for almost all organisms on earth provides energy to organisms through the process of photosynthesis. Autotrophic organisms produce carbohydrates that are passed down through the food chain.

Complete answer:
Photosynthesis is the process of conversion of light energy into chemical energy by autotrophic organisms through cellular respiration. This energy can be later released as metabolic energy which can be used to supply an organism's metabolic activities. This chemical energy is synthesized with the help of carbon dioxide and water molecules in the presence of light energy provided by the Sun. This synthesized chemical energy is stored in carbohydrate molecules in the form of sugars.
The major component in photosynthesis that is not recycled and is readily available is sunlight.
Sunlight is a part of the electromagnetic radiation emitted by the Sun. It is generally composed of infrared, ultraviolet and visible light. The ultraviolet radiation emitted by the sun has both useful as well as harmful consequences. The UV radiation is a prerequisite for the synthesis of vitamin $D_{3}$. UV radiation is also a mutagen that causes skin cancer.
Sunlight plays a major role in photosynthesis.

Note:
Photosynthetic autotrophs convert the light energy from the sunlight into chemical energy. This chemical energy is used for the synthesis of carbohydrates and energy to fuel the basic activities of an organism.
Prehistoric humans gathered plants to derive energy from them. These skills were passed down to later generations.