Different living things use different ways to create energy, depending on where they live and what they need. Here are some key methods they use:

1. Aerobic Respiration:

   • Most eukaryotes, like us humans, use aerobic respiration to make energy.
   • This method can produce about 36 to 38 ATP molecules from one glucose molecule.
   • It needs oxygen and goes through three main steps: glycolysis, the Krebs cycle, and oxidative phosphorylation.

2. Anaerobic Respiration:

   • On the other hand, some organisms, like yeast, use a process called fermentation when there isn't much oxygen available.
   • This only makes about 2 ATP per glucose molecule.
   • It also creates byproducts like ethanol or lactic acid, which can be found in low-oxygen places.

3. Variations in Metabolism:

   • Some bacteria have the ability to switch between aerobic and anaerobic respiration, depending on how much oxygen is around. This shows that they can adapt and be flexible with their energy production.

Learning about these different energy-making processes helps us understand the amazing variety of life and how different organisms generate energy in their own ways.