Module 2 Part B Cell Function and Energetics


1. Define the following: entropy, coupled reactions, energy of activation, active site, enzyme inhibition, diffusion, exocytosis, endocytosis, stomata, stroma, thylakoids, light reactions, Calvin cycle, cristae, glycolysis, electron transport chain, fermentation

2. Compare and contrast the two different types of energy.

3. Describe the two energy laws.

4. Relate the structure of ATP to its function.

5. Explain how ATP is used and produced.

6. Explain the importance of enzymes and how they work.

7. Compare and contrast the 3 types of transport.

8. Explain what happens when plant and animal cells are placed in hypertonic, hypotonic and isotonic solutions.

9. Compare and contrast photosynthesis, cellular respiration and fermentation.

10. Describe how photosynthesis benefits plants and humans.

11. Explain why tree leaves look green in the summer and orange/yellow in the fall.

12. Briefly explain the 3 steps of cellular respiration.

13. Relate the structure of the cristae to their purpose.

14. Explain how fermentation can directly and indirectly benefit humans.

15. Describe the two types of fermentation.

16. List the number of ATP produced per molecule of glucose in cellular respiration and in fermentation.


Chapter 5

5.1  What Is Energy?

Energy is the ability to do work.

There are two basic forms of energy.

1. Potential energy is stored energy or energy at rest. Examples of things with potential energy- a spring loaded mouse trap, a rock at the top of a mountain, or a gallon of gasoline.

2. Kinetic energy is energy of motion or energy in use. A rolling car or bowling ball have kinetic energy.

Energy is constantly being exchanged between these two forms.  For example, when your car engine burns gasoline, the potential energy of the gasoline is converted into kinetic energy. When the mouse hits the trigger of a trap, the spring's potential energy is converted into kinetic energy. When a rock tumbles down a mountain, its potential energy is converted into kinetic energy.


Measuring Energy

Energy can be measured in different units.

Food energy is measured in calories- a calorie is the amount of heat (energy) required to raise the temperature of one gram of water by 1 °C.

Food labels list the caloric value of food in kilocalories (there are 1,000 calories in one kilocalorie). This is listed on food labels as either a kcal or an uppercase "C".


Two Energy Laws

Energy laws describe the principles of energy flow and energy conversion.

The law of conservation of energy says that energy cannot be created or destroyed, but can change from one form to another.

Example- when you burn a gallon of gasoline, you do not destroy the energy. You just convert it from chemical energy into light energy and heat energy. 

The second energy law says that energy cannot be changed from one form to another without a loss of usable energy.

Most of the energy lost during energy interconversions is lost as heat.

Example: Your computer monitor converts electricity into light, but not all of the electricity is converted into light. Some of the electricity is wasted in the conversion and is given off as heat.


Another way to state the second energy law is that every energy transformation leads to more disorder or randomness.

The degree of disorder or disorganization is called entropy.



entropy and the distribution of hydrogen ions

Figure 1 has less entropy (more order) than Figure 2

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Firewood has less entropy than wood ashes.




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