Biology / Unit 3: Cellular Energy
3.6 Comparing Photosynthesis and Respiration
Notes
Photosynthesis and cellular respiration are linked: the products of one are the reactants of the other.
- Photosynthesis stores energy in glucose; respiration releases it as ATP.
- Photosynthesis uses $\text{CO}_2$ and releases $\text{O}_2$; respiration uses $\text{O}_2$ and releases $\text{CO}_2$.
- Photosynthesis happens in chloroplasts (plants, algae, some bacteria). Respiration happens in mitochondria (almost all eukaryotes, including plants).
- Together they cycle carbon and oxygen through ecosystems.
Practice
Which organisms carry out cellular respiration?
Plants make glucose but must also break it down for ATP.
A sealed jar contains a plant and a mouse in the light. Why can the mouse survive longer than it would alone?
The two processes are complementary: each uses the other's products.
Which statement is true?
Glucose and O2 from photosynthesis are used in respiration.
Ready for more? Take the Unit 3 test.