1. Cellular Energy
Indicator B – 3.3:
Recognize the overall structure of adenosine triphosphates (ATP) – namely, adenine, the sugar ribose, and three phosphate groups – and summarize its functions (including the ATP-ADP [adenosine diphosphate] cycle).

2. Key Concepts
ATP structure
ATP – ADP cycle

3. It is Essential For You to Know…
ATP is the most important biological molecule that supplies energy to the cell.
A molecule of ATP is composed of three parts:
A nitrogenous base (adenine)
A sugar (ribose)
Three phosphate groups bonded together by “high energy” bonds.
Cells break phosphate bonds as needed to supply energy for most cellular functions, leaving adenosine diphosphate (ADP) and a phosphate available for reuse.
The steps in the ATP – ADP cycle

4. OBJECTIVES Recognize the overall structure of an ATP molecule.
Summarize the function of ATP.
Illustrate the relationship between ATP and ADP.
Interpret diagrams and equations of the ATP-ADP cycle.

5. Vocabulary Define the following vocabulary terms: ATP ADP
Chemosynthesis
Heterotroph
Autotroph
Bond energy

6. What do you think about when you hear the word ENERGY?

7. Forms of Energy
List some forms of energy you are familiar with and indicate which one(s) would be used by a living to live.

9. Think About This…
Would you rather have fifty $1 bills or one $50 bill? Why?

10. Remember… Energy is the ability to do work.
All living things require energy.
Energy comes from foods-whether they are made or taken in.
The sun is the ultimate source of energy.

11. Autotrophs and Heterotrophs
To live, all organisms must release the energy in sugars and other compounds.
Autotrophs
Plants and some other types of organisms are able to use light energy from the sun to produce food.
Called producers
Heterotrophs
Called consumers

12. Chemical Energy and ATP
Energy comes in many forms:
light, heat, electricity
Energy can be stored.
Activities of the cell are powered by chemical fuels.

13. The chemical energy used for most cell processes is carried by ATP.
Molecules in food store chemical energy in their bonds.
Starch molecule
Glucose molecule

14. Chemical Energy and ATP
ATP and ADP
ATP (adenosine triphosphate) is one of the principle compounds that living things use to store energy
adenine group, ribose, 3 phosphates
ADP (adenosine diphosphate)
Adenine group, ribose, 2 phosphates

15. What Do ATP & ADP Look Like?
triphosphate
adenosine
diphosphate
tri=3
di=2

16. Chemical Energy and ATP
ATP and ADP
ATP and ADP are different, but related
The difference is the key way in which they store energy.
When a cell has energy available, it can store small amounts of energy by adding a phosphate group to the ADP molecule
ADP + Energy  ATP
When ATP releases that stored energy, it becomes ADP
ATP – Energy  ADP

17. phosphate removed

19. ATP and Glucose Foods that you eat do not contain ATP.
First the foods must be digested and broken down into smaller molecules that can be used to make ATP.
The amount of ATP made from the food depends on the type of food digested (protein, carbohydrate, lipid).
Lipids store the most amount of ATP
80% of the Energy in your body comes from fats.
146 ATP molecules from a triglyceride
36 ATP molecules can be made from Glucose

20. ATP and Glucose
Cells store small amounts of Energy in the form of ATP.
Used for quick, cellular processes in which Energy is required immediately
Active Transport
Organisms require longer lasting Energy
Stored in the form of glucose
Glucose can store 90 times more Energy than ATP.
Excess glucose is converted into fat if not used.

21. Stored Glucose
Animals: Glycogen
Plants: Cellulose

22. calorie vs. Calorie calorie is a unit of energy
the amount of heat energy required to raise the temperature of 1 gram of water up 1 degree Celsius (1.8 degrees Fahrenheit).
When applied to food, we are actually talking about a kilocalorie (1000 calories)
The measure of Calories gives us an indication of the potential energy that food possesses.
1 gram of Protein = 4 Calories
1 gram of Carbohydrate = 4 Calories
1 gram of Fat = 9 Calories

23. Energy in Foods 1 kcal = 4186.8 J = 1000 cal
In many countries outside of the US and UK, food energy is measured by the kilojoule.

25. Chemosynthesis
Some organisms don’t use light energy to produce chemical energy.
They may live in a place where sunlight is not present or strong enough like hydrothermal vents.
These organisms use chemosynthesis.