Mastery Check #2 - Cellular Respiration
Why do we eat? Why do we need oxygen?
Animals and plants need energy to do everything that they do. Where does this energy come from? It comes from the food that we eat. When we eat food, our body breaks it down into a molecule called glucose. Glucose then combines with the oxygen that we breathe to release energy in the form of ATP. As the glucose is broken down by the oxygen, it produces two waste products. These two waste products are carbon dioxide and water. This process can be summarized in the chemical equation shown below.
Animals and plants need energy to do everything that they do. Where does this energy come from? It comes from the food that we eat. When we eat food, our body breaks it down into a molecule called glucose. Glucose then combines with the oxygen that we breathe to release energy in the form of ATP. As the glucose is broken down by the oxygen, it produces two waste products. These two waste products are carbon dioxide and water. This process can be summarized in the chemical equation shown below.
How is energy transformed in cellular respiration and in photosynthesis?
Cellular respiration takes chemical energy (food) and turns it into energy that can be used to move and create heat. Where did the food get its chemical energy? That comes from the process of photosynthesis. Photosynthesis takes light energy and turns it into chemical energy (glucose or food). These energy transformations are summarized below:
Cellular respiration takes chemical energy (food) and turns it into energy that can be used to move and create heat. Where did the food get its chemical energy? That comes from the process of photosynthesis. Photosynthesis takes light energy and turns it into chemical energy (glucose or food). These energy transformations are summarized below:
Light energy (sunlight) --> chemical energy (food) --> mechanical energy (movement of animal) --> heat energy
How do photosynthesis and respiration relate to each other?
If you look closely and the chemical equations for photosynthesis and respiration you will notice that they use the same four chemicals. Photosynthesis produces oxygen and glucose. Respiration then uses that oxygen and glucose to produce carbon dioxide and water. Photosynthesis then uses that carbon dioxide and water to make more oxygen and glucose. It is a continuous cycle that helps keep ecosystems in balance. The picture below summarizes this process.
If you look closely and the chemical equations for photosynthesis and respiration you will notice that they use the same four chemicals. Photosynthesis produces oxygen and glucose. Respiration then uses that oxygen and glucose to produce carbon dioxide and water. Photosynthesis then uses that carbon dioxide and water to make more oxygen and glucose. It is a continuous cycle that helps keep ecosystems in balance. The picture below summarizes this process.