The two reactions that drive life within cells are:
1. **Photosynthesis**: This reaction occurs in plant cells and some algae. It is the process by which these organisms convert sunlight into energy in the form of glucose (sugar). During photosynthesis, plants use chlorophyll to capture sunlight, water, and carbon dioxide from the air to produce glucose and oxygen as byproducts. This reaction is crucial for providing energy to the cell and releasing oxygen into the atmosphere.
2. **Cellular Respiration**: This reaction takes place in the mitochondria of cells in both plants and animals. It is the process by which cells break down glucose to produce energy in the form of adenosine triphosphate (ATP). Cellular respiration involves three main stages: glycolysis, the citric acid cycle, and oxidative phosphorylation. Through these stages, cells extract energy from glucose molecules, releasing carbon dioxide and water as byproducts. This reaction is essential for providing energy to the cell for various metabolic processes and activities.
These two reactions, photosynthesis, and cellular respiration, work together in ecosystems to cycle energy and nutrients, driving the life processes within cells and sustaining life on Earth.
