2. Chapter 8 Cellular Energy
Section 1: How Organisms Obtain Energy
Section 2: Photosynthesis
Section 3: Cellular Respiration

3. BELLRINGER!!! Write the following chemical equations in your
science notebook:
PHOTOSYNTHESIS
carbon dioxide + water → glucose + oxygen
CELLULAR RESPIRATION
glucose + oxygen → carbon dioxide + water + energy

4. How Organisms Obtain Their Energy (Section 8.1)
MAIN IDEA:
All living
organisms use
energy to carry
out all biological
processes.

5. How Organisms Obtain Their Energy (Section 8.1)
Objectives:
Summarize the two laws of thermodynamics.
Compare and Contrast autotrophs and heterotrophs.
Describe how ATP works in a cell.

6. trophic level – each step in a food chain or a food web.
Review Vocabulary
trophic level –
each step in a
food chain or a
food web.

7. NEW VOCABULARY energy thermodynamics metabolism photosynthesis
cellular respiration
adenosine triphosphate (ATP)

8. Transformation of Energy
Chapter 8
Cellular Energy
8.1 How Organisms Obtain Energy
Transformation of Energy
Energy is the ability to do work.
Thermodynamics is the study of the flow and transformation of energy in the universe.

9. Laws of Thermodynamics
Chapter 8
Cellular Energy
8.1 How Organisms Obtain Energy
Laws of Thermodynamics
First law — energy can be converted from one form to another and it cannot be created nor destroyed.

10. Chapter 8
Cellular Energy
8.1 How Organisms Obtain Energy
Second law — energy cannot be converted without the loss of usable energy.
A diagram that can show the relative amounts of energy, biomass, or numbers of organisms at each trophic level.
In a pyramid of energy, approximately 90% of the energy is transformed at each level (10 percent law).

11. 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.
Chemoautotrophs are organisms that use inorganic substances such as hydrogen sulfide as a source of energy.

12. REMEDIATION (True or False)
Heterotrophs are dependent on autotrophs.
TRUE!
Autotrophs depend on heterotrophs for food.
FALSE
Autotrophs make their own food.
Heterotrophs make food using light energy.

13. 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 (anabolic pathway)
Cellular respiration — organic molecules are broken down to release energy for use by the cell (catabolic pathway)

14. 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.

15. 8.1 Section Summary
The laws of thermodynamics control the flow and transformation of energy in organisms.
Autotrophs produce their own food, whereas heterotrophs obtain energy from the food they digest.
Cells store and release energy through coupled anabolic and catabolic reactions.
The energy released from the breakdown of ATP drives cellular activities.

16. Photosynthesis (Section 8.2)
MAIN IDEA:
Light energy is
trapped and
converted into
chemical energy
during
photosynthesis.

17. Photosynthesis (Section 8.2)
Objectives:
Summarize the two phases of photosynthesis.
Explain the function of a chloroplast during the light reactions.

18. REVIEW VOCABULARY carbohydrate – an organic compound
containing only carbon, hydrogen, and
oxygen, usually in a 1:2:1 ratio.

19. NEW VOCABULARY thylakoid granum stroma pigment NADP+ Calvin cycle
rubisco

21. Overview of Photosynthesis
Chapter 8
Cellular Energy
8.2 Photosynthesis
Overview of Photosynthesis
Photosynthesis occurs in two phases.
Light-dependent reactions
Light-independent reactions

22. Phase One: Light Reactions
Chapter 8
Cellular Energy
8.2 Photosynthesis
Phase One: Light Reactions
The absorption of light is the
first step in photosynthesis.
Chloroplasts capture light energy.

23. Photosynthesis (Section 8.2)
Carotenoids produce the colors of carrots and sweet potatoes.

24. Photosynthesis (Section 8.2)
As trees prepare to lose their leaves before winter, the chlorophyll molecules break down, revealing the colors of the pigments.

25. Phase Two: The Calvin Cycle
Chapter 8
Cellular Energy
8.2 Photosynthesis
Phase Two: The Calvin Cycle
In the second phase of photosynthesis, called the Calvin cycle, energy is stored in organic molecules such as glucose.

26. Chapter 8
Cellular Energy
8.2 Photosynthesis
An enzyme called rubisco converts inorganic carbon dioxide molecules into organic molecules during the final step of the Calvin cycle.

27. C4 plants keep their stomata (plant cell pores) closed during
Chapter 8
Cellular Energy
8.2 Photosynthesis
Alternative Pathways
C4 plants keep their stomata
(plant cell pores) closed during
hot days.

28. Alternative Pathways 8.2 Photosynthesis
Chapter 8
Cellular Energy
8.2 Photosynthesis
Alternative Pathways
CAM plants pathway occurs in water-conserving plants that live in deserts, salt marshes, and other environments where access to water is limited.

29. 8.2 Section Summary Plants contain chloroplasts with light-
absorbing pigments that convert light energy into chemical energy.
Photosynthesis is a two-phase process that consists of the light reactions and the Calvin cycle.
In the light reactions, autotrophs trap and convert light energy into chemical energy in the form of NADPH and ATP.
In the Calvin cycle, chemical energy in ATP and NADPH is used to synthesize carbohydrates such as glucose.

30. CELLULAR RESPIRATION Section 8.3
MAIN IDEA: Living organisms obtain
energy by breaking down organic
molecules during cellular respiration.

31. Section 8.3 Objectives Summarize the stages of cellular respiration.
Compare alcoholic fermentation and lactic acid fermentation.

32. Review Vocabulary cyanobacterium – a type of eubacterium that is
a photosynthetic autotroph.
mitochondria – membrane-bound organelles
that convert fuel into energy that is available to
the rest of the cell (often referred to as the
“powerhouses” of cells).

33. NEW VOCABULARY anaerobic process aerobic respiration aerobic
glycolysis
Krebs cycle
fermentation

34. 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.

35. Review of Photosynthesis and an Overview of Cellular Respiration
Chapter 8
Cellular Energy
8.3 Cellular Respiration
Review of Photosynthesis and an Overview of Cellular Respiration

36. 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

37. 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.

38. 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.

39. 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 24 ATP

40. 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
Cellular Respiration

41. Section 8.3 Summary
Many living organisms use cellular respiration to break down glucose.
The stages of cellular respiration are glycolysis, Krebs cycle, and electron transport.
In the absence of oxygen, cells can sustain glycolysis by fermentation.

43. Chapter Resource Menu Chapter Diagnostic Questions
Cellular Energy
Chapter Resource Menu
Chapter Diagnostic Questions
Formative Test Questions
Chapter Assessment Questions
Standardized Test Practice
biologygmh.com
Glencoe Biology Transparencies
Image Bank
Vocabulary
Animation
Click on a hyperlink to view the corresponding lesson.

44. 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.

45. 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

46. At the end of the Calvin cycle, where is energy stored?
Chapter 8
Cellular Energy
Chapter Diagnostic Questions
At the end of the Calvin cycle, where is energy
stored?
NADPH
ATP
chloroplast
glucose

47. Which law of thermodynamics explains
Chapter 8
Cellular Energy
8.1 Formative Questions
Which law of thermodynamics explains
why the ladybug receives the least amount
of usable energy?

48. the first law of thermodynamics the second law of thermodynamics
Chapter 8
Cellular Energy
8.1 Formative Questions
the first law of thermodynamics
the second law of thermodynamics

49. All of the energy from the food you eat comes from the sun.
Chapter 8
Cellular Energy
8.1 Formative Questions
True or False
All of the energy from the food you eat
comes from the sun.

50. 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.

51. 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.

52. Where in the plant cell does photosynthesis take place?
Chapter 8
Cellular Energy
8.2 Formative Questions
Where in the plant cell does photosynthesis
take place?
chloroplasts
Golgi apparatus
mitochondria
vacuoles

53. Which range of wavelengths is reflected by chlorophylls a and b?
Chapter 8
Cellular Energy
8.2 Formative Questions
Which range of wavelengths is reflected by
chlorophylls a and b? nm nm nm nm

54. How are the C4 pathway and the CAM pathway
Chapter 8
Cellular Energy
8.2 Formative Questions
How are the C4 pathway and the CAM pathway
an adaptive strategy for some plants?
They accelerate photosynthesis.
They release more oxygen.
They help the plant conserve water.
They reduce the requirement for ATP.

55. 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

56. 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
fermentation
aerobic pathway anaerobic pathway

57. 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
Calvin cycle

58. Which molecule generated by the Krebs cycle is a waste product?
Chapter 8
Cellular Energy
8.3 Formative Questions
Which molecule generated by the Krebs
cycle is a waste product?
hydrogen
CO2 O2
glucose

59. Look at the following figure. Which part of the
Chapter 8
Cellular Energy
Chapter Assessment Questions
Look at the following figure. Which part of the
chloroplast is a sac-like membrane arranged in
stacks?
grana
stroma
thylakoids
Golgi apparatus

60. 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

61. Look at the following figure. Which molecule is
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

62. A B Which metabolic process is photosynthesis?
Chapter 8
Cellular Energy
Standardized Test Practice
Which metabolic process is photosynthesis? A B

63. At the beginning of photosynthesis, which
Chapter 8
Cellular Energy
Standardized Test Practice
At the beginning of photosynthesis, which
molecule is split to produce oxygen (O2) as
a waste product?
CO2
H2O
C6H12O6
3-PGA

64. Glencoe Biology Transparencies
Chapter 8
Cellular Energy
Glencoe Biology Transparencies

65. Chapter 8
Cellular Energy
Image Bank

66. Section 1 Vocabulary energy thermodynamics metabolism Photosynthesis
Chapter 8
Cellular Energy
Vocabulary
Section 1
energy
thermodynamics
metabolism
Photosynthesis
cellular respiration
adenosine triphosphate (ATP)

67. Section 2 Vocabulary thylakoid granum stroma pigment NADP+
Chapter 8
Cellular Energy
Vocabulary
Section 2
thylakoid
granum
stroma
pigment
NADP+
Calvin cycle
rubisco

68. Section 3 Vocabulary anaerobic process aerobic respiration
Chapter 8
Cellular Energy
Vocabulary
Section 3
anaerobic process
aerobic respiration
aerobic process
glycolysis
Krebs cycle
fermentation

69. Visualizing Electron Transport
Chapter 8
Cellular Energy
Animation
Visualizing Electron Transport

70. adenosine triphosphate (ATP)
energy
pigment
aerobic process
fermentation
photosynthesis
aerobic respiration
glycolysis
rubisco
anaerobic process
granum
stroma
Calvin cycle
Krebs cycle
thermodynamics
cellular respiration
metabolism
thylakoid