1. Copyright Pearson Prentice Hall
Biology
Copyright Pearson Prentice Hall

2. Energy and Life EQ How is ATP used in cells? What is photosynthesis?
Photo Credit: ©Stone
Copyright Pearson Prentice Hall

3. Autotrophs and Heterotrophs
Living things need energy to survive.
This energy comes from food. The energy in most food comes from the sun.
Where do plants get the energy they need to produce food?
Copyright Pearson Prentice Hall

4. Autotrophs and Heterotrophs
Plants and some other types of organisms are able to use light energy from the sun to produce food are called autotrophs.
Organisms that obtain their energy from the food they eat are called heterotrophs.
Copyright Pearson Prentice Hall

5. Copyright Pearson Prentice Hall
Questions
What type of organisms get their energy from the food they eat?
Heterotrophs
What type of organisms get their energy from the sun?
Autotrophs
Copyright Pearson Prentice Hall

6. Chemical Energy and ATP
Energy comes in many forms including light, heat, and electricity.
Energy can also be stored in chemical compounds.
Copyright Pearson Prentice Hall

7. Chemical Energy and ATP
An important chemical compound that cells use to store and release energy is adenosine triphosphate, abbreviated ATP.
ATP is used by all types of cells as their basic energy source.
Copyright Pearson Prentice Hall

8. Copyright Pearson Prentice Hall
Question
What is the chemical name of the compound that is used to store energy?
ATP
Write out the full name of ATP three times.
Adenosine triphosphate
Copyright Pearson Prentice Hall

9. Chemical Energy and ATP
ATP consists of:
adenine
ribose (a 5-carbon sugar)
3 phosphate groups
Adenine
Ribose
3 Phosphate groups
ATP is used by all types of cells as their basic energy source.
ATP
Copyright Pearson Prentice Hall

10. Chemical Energy and ATP
Storing Energy
ADP has two phosphate groups instead of three.
A cell can store small amounts of energy by adding a phosphate group to ADP.
ATP
ADP
Energy +
Energy
Adenosine Triphosphate (ATP)
Adenosine Diphosphate (ADP) + Phosphate
Partially charged battery
Fully charged battery
Copyright Pearson Prentice Hall

11. Chemical Energy and ATP
Releasing Energy
Energy stored in ATP is released by breaking the chemical bond between the second and third phosphates.
2 Phosphate groups P
ADP
Copyright Pearson Prentice Hall

12. Copyright Pearson Prentice Hall
Questions
Discuss with your partner the three components of ATP.
Adenine, ribose and three phosphate groups
Where is the energy in ATP stored?
Between the second and third phosphate groups.
Copyright Pearson Prentice Hall

13. Chemical Energy and ATP
What is the role of ATP in cellular activities?
Copyright Pearson Prentice Hall

14. Chemical Energy and ATP
The energy from ATP is needed for many cellular activities, including active transport across cell membranes, protein synthesis and muscle contraction.
ATP’s characteristics make it exceptionally useful as the basic energy source of all cells.
Copyright Pearson Prentice Hall

15. Using Biochemical Energy
Most cells have only a small amount of ATP, because it is not a good way to store large amounts of energy.
Cells can regenerate ATP from ADP as needed by using the energy in foods like glucose.
Copyright Pearson Prentice Hall

16. Copyright Pearson Prentice Hall
The key cellular process identified with energy production is photosynthesis. Photosynthesis is the process in which green plants use the energy of sunlight to convert water and carbon dioxide into high-energy carbohydrates and oxygen.
Copyright Pearson Prentice Hall

17. Copyright Pearson Prentice Hall
Question
Without looking in your notes, decribe photosynthesis to your neighbor.
Copyright Pearson Prentice Hall

18. Investigating Photosynthesis
The experiments performed by van Helmont, Priestley, and Ingenhousz led to work by other scientists who finally discovered that, in the presence of light, plants transform carbon dioxide and water into carbohydrates, and they also release oxygen.
Copyright Pearson Prentice Hall

19. The Photosynthesis Equation
The equation for photosynthesis is:
CO2 + H2O C6H12O6 + O2
carbon dioxide + water sugars + oxygen
Light
Light
Copyright Pearson Prentice Hall

20. Copyright Pearson Prentice Hall
Question
Write the balanced equation for photosynthesis.
6CO2 + 6H2O  C6H12O6 + 6O2
Copyright Pearson Prentice Hall

21. The Photosynthesis Equation
Photosynthesis uses the energy of sunlight to convert water and carbon dioxide into high-energy sugars and oxygen.
Copyright Pearson Prentice Hall

22. The Photosynthesis Equation
Light energy
H2O
Light-Dependent Reactions (thylakoids) O2
ADP NADP+
ATP NADPH
Photosynthesis is a series of reactions that uses light energy from the sun to convert water and carbon dioxide into sugars and oxygen.
CO2 + H20
Sugar
Calvin Cycle (stroma)
Copyright Pearson Prentice Hall

23. Copyright Pearson Prentice Hall
Light and Pigments
Light and Pigments
How do plants capture the energy of sunlight?
In addition to water and carbon dioxide, photosynthesis requires light and chlorophyll.
Copyright Pearson Prentice Hall

24. Copyright Pearson Prentice Hall
Light and Pigments
Plants gather the sun's energy with light-absorbing molecules called pigments.
The main pigment in plants is chlorophyll.
There are two main types of chlorophyll:
chlorophyll a
chlorophyll b
Copyright Pearson Prentice Hall

25. Copyright Pearson Prentice Hall
Light and Pigments
Chlorophyll does not absorb light will in the green region of the spectrum. Green light is reflected by leaves, which is why plants look green.
100 80 60 40 20
Chlorophyll b
Estimated Absorption (%)
Chlorophyll a
Photosynthesis requires light and chlorophyll. In the graph above, notice how chlorophyll a absorbs light mostly in the blue-violet and red regions of the visible spectrum, whereas chlorophyll b absorbs light in the blue and red regions of the visible spectrum.
Wavelength (nm)
Copyright Pearson Prentice Hall