1. Autotrophs and Heterotrophs
Chapter 8
Cellular Energy
8.1 How Organisms Obtain Energy
Autotrophs and Heterotrophs
Autotrophs are organisms that make their own food.
Heterotrophs are organisms that need to ingest food to obtain energy.

2. All of the chemical reactions in a cell
Chapter 8
Cellular Energy
8.1 How Organisms Obtain Energy
Metabolism
All of the chemical reactions in a cell
Photosynthesis—light energy from the Sun is converted to chemical energy for use by the cell
Cellular respiration—organic molecules are broken down to release energy for use by the cell

3. ATP: The Unit of Cellular Energy
Chapter 8
Cellular Energy
8.1 How Organisms Obtain Energy
ATP: The Unit of Cellular Energy
ATP releases energy when the bond between the second and third phosphate groups is broken, forming a molecule called adenosine diphosphate (ADP) and a free phosphate group.
ATP

4. Overview of Cellular Respiration
Chapter 8
Cellular Energy
8.3 Cellular Respiration
Overview of Cellular Respiration
Organisms obtain energy in a process called cellular respiration.
The equation for cellular respiration is the opposite of the equation for photosynthesis.

5. Cellular respiration occurs in two main parts.
Chapter 8
Cellular Energy
8.3 Cellular Respiration
Cellular respiration occurs in two main parts.
Glycolysis
Aerobic respiration

6. Chapter 8
Cellular Energy
8.3 Cellular Respiration
Glycolysis
Glucose is broken down in the cytoplasm through the process of glycolysis.
Two molecules of ATP and two molecules of NADH are formed for each molecule of glucose that is broken down.

7. Glycolysis has a net result of two ATP and two pyruvate.
Chapter 8
Cellular Energy
8.3 Cellular Respiration
Krebs Cycle
Glycolysis has a net result of two ATP and two pyruvate.
Most of the energy from the glucose is still contained in the pyruvate.
The series of reactions in which pyruvate is broken down into carbon dioxide is called the Krebs cycle.

8. Chapter 8
Cellular Energy
8.3 Cellular Respiration
The net yield from the Krebs cycle is six CO2 molecules, two ATP, eight NADH, and two FADH2.
The Krebs Cycle

9. Final step in the breakdown of glucose
Chapter 8
Cellular Energy
8.3 Cellular Respiration
Electron Transport
Final step in the breakdown of glucose
Point at which ATP is produced
Produces 34 ATP

10. Anaerobic Respiration
Chapter 8
Cellular Energy
8.3 Cellular Respiration
Anaerobic Respiration
The anaerobic pathway that follows glycolysis
Two main types
Lactic acid fermentation
Alcohol fermentation
Energy in a Cell

11. Which statement describes the law of conservation of energy?
Chapter 8
Cellular Energy
Chapter Diagnostic Questions
Which statement describes the law of
conservation of energy?
Energy cannot be converted or destroyed.
Energy can be converted and destroyed.
Energy can be converted but not destroyed.
Energy can be destroyed but not converted. A B C D
CDQ 1

12. In which metabolic process are molecules
Chapter 8
Cellular Energy
Chapter Diagnostic Questions
In which metabolic process are molecules
broken down to produce carbon dioxide and
water?
photosynthesis
cellular respiration
homeostasis
fermentation A B C D
CDQ 2

13. Chapter 8
Cellular Energy
8.1 Formative Questions
Which law of thermodynamics explains why the ladybug receives the least amount of usable energy? A B
the first law of thermodynamics
the second law of thermodynamics
FQ 1

14. All of the energy from the food you eat comes from the sun.
Chapter 8
Cellular Energy
8.1 Formative Questions
All of the energy from the food you eat comes from the sun.
true
false A B
FQ 2

15. Why is cellular respiration a catabolic pathway?
Chapter 8
Cellular Energy
8.1 Formative Questions
Why is cellular respiration a catabolic pathway?
Energy is used to form glucose and oxygen.
Energy is converted from water to carbon dioxide.
Energy that is lost is converted to thermal energy.
Energy is released by the breakdown of molecules. A B C D
FQ 3

16. Why is adenosine triphosphate (ATP) such an
Chapter 8
Cellular Energy
8.1 Formative Questions
Why is adenosine triphosphate (ATP) such an
important biological molecule?
It captures light energy from the sun.
It is produced in anabolic pathways.
It stores and releases chemical energy.
It converts mechanical energy to thermal energy. A B C D
FQ 4

17. Which mechanism of photosynthesis uses
Chapter 8
Cellular Energy
8.2 Formative Questions
Which mechanism of photosynthesis uses
the movement of hydrogen ions (H+) across
a concentration gradient to synthesize ATP?
absorption
chemiosmosis
electron transport
C2 pathway A B C D
FQ 7

18. What is the overall purpose of cellular respiration?
Chapter 8
Cellular Energy
8.3 Formative Questions
What is the overall purpose of cellular
respiration?
to make ATP
to process H2O
to store glucose
to deliver oxygen A B C D
FQ 9

19. Which represents the general sequence of cellular respiration?
Chapter 8
Cellular Energy
8.3 Formative Questions
Which represents the general sequence of
cellular respiration?
TCA cycle  chemiosmosis  glycolysis
glycolysis  Krebs cycle  electron transport
electron absorption  catalysis  phosphorylation
aerobic pathway  anaerobic pathway  fermentation A B C D
FQ 10

20. Which stage of cellular respiration is the anaerobic process?
Chapter 8
Cellular Energy
8.3 Formative Questions
Which stage of cellular respiration is the
anaerobic process?
glycolysis
Krebs cycle
electron transport A B C
FQ 11

21. CoA CO2 FADH2 NADH Which molecule generated by the Krebs
Chapter 8
Cellular Energy
8.3 Formative Questions
Which molecule generated by the Krebs
cycle is a waste product?
CoA
CO2
FADH2
NADH A B C D
FQ 12

22. pyruvate is broken down into what compound?
Chapter 8
Cellular Energy
Chapter Assessment Questions
During the Krebs cycle,
pyruvate is broken down
into what compound?
H2O O2 CO
CO2 A B C D
CAQ 2

23. Chapter 8
Cellular Energy
Chapter Assessment Questions
Look at the following figure. Which molecule is released when ATP becomes ADP?
phosphate group
water molecule
ribose sugar
energy cells A B C D
CAQ 3

24. What is the final step of cellular respiration?
Chapter 8
Cellular Energy
Standardized Test Practice
What is the final step of cellular respiration?
O2 and H+ form H2O.
Electrons and H2O generate ATP.
C6H12O6 is broken down into CO2.
NADH and FADH2 gain electrons. A B C D
STP 5

25. an increased demand for ATP
Chapter 8
Cellular Energy
Standardized Test Practice
What prevents pyruvate from entering the Krebs cycle and instead results in this pathway?
a buildup of CO2
a lack of oxygen
an excess of glucose
an increased demand for ATP A B C D
STP 6

26. Which is not a process that occurs in both
Chapter 8
Cellular Energy
Standardized Test Practice
Which is not a process that occurs in both
cellular respiration and glycolysis?
chemiosmosis
electron transport
glycolysis
production of G3P A B C D
STP 7