Respiration releases energy from glucose: with oxygen in mitochondria, or without it as lactic acid in muscles and ethanol in yeast.
What you will learn
- Give the equations for aerobic and anaerobic respiration
- Compare the energy released by each type
- Describe fermentation and its uses in baking and brewing
- Calculate energy and rates from respiration data
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 locked.
In this lesson
- Aerobic respiration
- Without oxygen
- Try it: Name the products
11 practice questions, marked as you go; about 25 minutes in all.
Key terms
Aerobic, Anaerobically, Fermentation
In this unit: Bioenergetics: photosynthesis and respiration
Photosynthesis and its rate, limiting factors and the pondweed practical, aerobic and anaerobic respiration, exercise and metabolism.