Brainlag PlusRespiration releases energy from glucose: with oxygen in mitochondria, or without it as lactic acid in muscles and ethanol in yeast.
Aerobic respiration
Every living cell respires all the time to release energy from glucose.
With plenty of oxygen it is aerobic, and most of it happens in the mitochondria.
glucose + oxygen → carbon dioxide + water
C6H12O6 + 6O2 → 6CO2 + 6H2O
It is the photosynthesis equation the other way round, and it is exothermic: it transfers energy to the surroundings. Organisms use the energy to build large molecules from small ones, to contract muscles, and (birds and mammals) to keep their body temperature steady.
Plants respire too, day and night. In bright light they photosynthesise faster than they respire, so overall they take in carbon dioxide.
The rest of this lesson and its 11 practice questions are in Plus.
Screen 1 of 3, free to read.
- 11 exam-style questions, marked as you go, each with a worked solution
- Anything you get wrong is saved to your flashcards