1. Compare and contrast photosynthesis and cellular respiration.
2. Identify the reactants and products in photosynthesis and cellular respiration.
3. Describe what types of cells perform these processes.
4. Classify these processes as chemical reactions.
Photosynthesis and cellular respiration are two chemical reactions that happen inside of cells and are very important to living systems. They are both chemical reactions because in each process, matter is changed into new forms of matter. Photosynthesis occurs in the chloroplasts of plant cells (as well as algae and some bacteria). Cellular respiration occurs in the mitochondria of eukaryotic cells, both plant and animal.
The reactants of photosynthesis are water and carbon dioxide, which the plant takes in from the environment and reacts to make the products glucose and oxygen. The glucose stays in the plant (which may be eaten by heterotrophs) and much of the oxygen is released into the environment (where it is taken in by animals).
The reactants of cellular respiration are glucose (that is provided to animals by the plant-based foods we eat) and oxygen (breathed in from the environment through the respiratory system and carried to cells by the circulatory system), which react to produce the products carbon dioxide and water, which are exhaled back out into the environment. Energy is released by this chemical reaction, which is how cells get energy when mitochondria perform cellular respiration!