Analyze overall reactions including reactants and products for photosynthesis and respiration and factors which affect their rates. (pH, temperature, light, etc.)  Conclude that energy production by organisms is vital for maintaining homeostasis and that maintenance of homeostasis is necessary for life. 

This lesson focuses on energy production in the body through the digestion of food. The concepts covered here involve the expenditure of energy from nutrition and cellular respiration, with a particular focus on the strenuous energy demands of marathon running. For the learning activities, students will design their own menu to prepare for the big race, with careful attention to prevent hitting the wall's situation caused by depletion of a glycogen source in the body during extreme activity.

Students review the basics of respiration (breathing) and learn about the importance of oxygen to the human body as the fuel that allows our cells to produce energy from the food we eat.

In this activity, students are introduced to the relationship between food and energy. Students will observe what happens when yeast, a single-celled fungus, is provided with food (table sugar).