Lesson 13


Lesson 13 Notes


Energy Intake- the amount of energy in the chemical bonds of the foods and drink we eat

Energy Output- the total amount of energy that is lost during oxidation, our daily life activities, and stored as fat and glycogen.

calorie- the amount of energy that is required to raise the temperature of one gram of water, one degree Celcius

Calorie- (kilocalorie)- the amount of heat energy that is required to raise the temperature of 1000 grams of water, one degree Celcius (1000 grams =

1 kilogram)

Additional Notes:

In this lesson, students conducted an experiment that provides evidence of relative caloric content of two foods- a marshmallow and a cheese puff.

Each food was lit using a candle and held under a test tube filled with water. The students observe that the burning cheese puff causes a greater increase in the temperature of the water than the burning marshmallow does.

 Human body systems are fueled by the energy stored in chemical bonds. Release of this energy enables us to do many things- dance, sing, swim, think…

Which of the two foods has a higher energy content? The cheese puff has more energy per unit of volume than the marshmallow. This is demonstrated by the fact that the average increase in the

temperature by the cheese puff was considerably greater than that of the water heated by the marshmallow.

What do you think the process you observed during this inquiry might

have to do with calories? The difference in the amount by which the water temperature rose is an indication of the relative caloric value of the foods.

How is the process you observed during the inquiry similar to cellular

respiration? In both cases, foods were oxidized.

How is the process you observed in this lesson different from the

process of cellular respiration? The burning of the cheese puffs and marshmallows differs from cellular respiration in several ways. In the inquiry, the oxidation was initiated by an outside source (candle). The oxidation occurred very rapidly, and it created a flame. Most of the energy was released rather than stored. Although glucose is often the cell’s first choice for fuel, amino acids and digested fats are also usable sources of energy.