<< Back to Lessons Index
6th Grade Science / Lesson 9 - Energy Released in a Cell
|Energy Released in a Cell
|What will we be learning today?
- In this lesson, we are going to learn all about how energy is released in a cell.
|How Is Energy Released in a Cell?
- Energy for a cell's activities is locked within molecules of sugar.
- Plants store up the sugar for their own use.
- Animals get this energy by eating plants or other animals that have eaten plants.
- To use the energy, cells of an organism "unlock" the energy from sugar.
- The energy in a sugar molecule is "unlocked" or released by a process called respiration. Respiration takes place in cells in the mitochondria.
- Think of respiration as a process of burning a fuel, such as wood or coal. Sugar is the fuel. Usually the process requires oxygen, which living things take in from air or water.
- The sugar molecules are broken down, and energy and wastes are released. The wastes are water and carbon dioxide
- Some cells carry on respiration without oxygen, a process called fermentation.
- For example, oxygen may not reach all your muscle cells when you exercise. In this case fermentation releases the energy.
- It also releases a waste called lactic acid.
- One-celled organisms called yeasts carry on fermentation by feeding on sugars.
- They break the sugars down and produce carbon dioxide and a kind of alcohol called ethanol.
- Ethanol has many uses, from antifreeze to manufacturing.
- Ethanol is also being mixed with other chemicals to produce a fuel that can power motor vehicles.
- Scientists are working with plant products that can be fermented-wood chippings and corn, for example-to produce ethanol.
|Let's Review What We Learned Today!
- Now complete your worksheet!