Chemical Energy and Biological Processes
This page delves into the role of chemical energy in biological systems and introduces ATP as a key energy carrier.
The text explains that chemical energy drives changes in biological systems by making and breaking chemical bonds. It distinguishes between heterotrophic organisms, which derive energy from food, and autotrophic organisms, which convert light energy to chemical energy through photosynthesis.
The page then focuses on ATP adenosinetriphosphate as the primary energy carrier in organisms. Key points include:
- ATP is not an energy store but makes energy available when needed
- The human body contains only about 5g of ATP but makes and breaks down about 50kg daily
- ATP is synthesized when energy is available e.g.,inmitochondria and broken down when energy is needed e.g.,formusclecontraction
The structure of ATP is also detailed, showing its components:
- Adenine apurinebase
- Ribose sugar
- Three phosphate groups
Highlight: ATP plays a crucial role in energy transfer within cells, making it a central topic in A Level Biology Eduqas notes.
Example: Green plants are autotrophic organisms that convert light energy to chemical energy through photosynthesis.
