Photosynthesis: Homework Packet - Biology

Photosynthesis:
Homework Packet

Name:_______________________

Completion:

1. A membrane protein called __________________________________________allows H+ ions to pass through the
thylakoid membrane and into the stroma.
2. During the Calvin cycle, molecules of __________________________ supply the carbon component of carbohydrates.
3. Heterotrophs are living things that cannot make their own _______________________________________________.
4. _____________________________ and ____________________________ are the two types of molecules organisms
use for chemical energy.
5. Glucose and ___________________________________________ are the products of photosynthesis.
6. Photosynthesis is the process in which energy from _________________________________ is transferred to glucose.
7. Without photosynthesis, there would be no ____________________________________________ in the atmosphere.
8. ____________________________________ make their own food, whereas __________________________________
get food by eating other living things.
9. ____________________________________________________ are the organelles where photosynthesis takes place.
10. Stage I of photosynthesis is called the _______________________________________________________________.
11. Stage II of photosynthesis is called the _______________________________________________________________.
12. During the first stage of photosynthesis, a molecule of _____________________________________ gas is released.
13. Chloroplasts contain _________________________________________, which are made out of sac-like membranes,
known as ___________________________________________________ membranes.
14. Most ___________________________________________________ make food using photosynthesis.
15. The green pigment, _______________________________________________, absorbs light to start photosynthesis.
16. During the first stage of photosynthesis, two __________________________ are passed from molecule to molecule
down the electron-transport chain.
17. ________________________________ turns of the Calvin cycle produce one molecule of _____________________.
18. During the light reactions, ___________________________ and ______________________________ are produced.
19. During the Calvin cycle, _______________________________ is produced.
20. What inorganic carbon containing molecule enters the Calvin Cycle?______________________ What organic carbon
containing molecule is produced?__________________________
21. What is the DIRECT source of electron and hydrogen that are used to make sugar in the Calvin Cycle?____________
22. What is the DIRECT source of energy used to make glucose in the Calvin Cycle?_______________________________
23. Plants gather the sun’s energy with light-absorbing molecules called_______________________________________
24. Chloroplasts contain saclike photosynthetic membranes called____________________________________________
25. The region outside the thylakoid membranes in the chloroplasts is called the_________________________________

Matching:

a. Calvin cycle i. chemosynthesis q. chlorophyll
b. chloroplast j. electron transport chain r. glucose
c. light reactions k. NADPH s. photosynthesis
d. photosystem l. stroma t. thylakoid membrane
e. ATP m. autotroph u. cellular respiration
f. consumer n. decomposer v. energy
g. food o. food chain w. glucose
h. heterotroph p. photosynthesis x. producer

_____ 26. the process in which glucose is broken down and ATP is made
_____ 27. organism at the end of a food chain
_____ 28. shows how energy and matter flow from producers to consumers
_____ 29. also known as autotrophs
_____ 30. the ability to do work
_____ 31. stores chemical energy in a concentrated, stable form
_____ 32. the energy-carrying molecule that cells use for energy
_____ 33. process that stores energy from sunlight in the chemical bonds of glucose
_____ 34. organisms that make their own food
_____ 35. all animals and fungi and many single-celled organisms
_____ 36. organisms that must eat
_____ 37. organic molecules that store energy in their chemical bonds
_____ 38. a green pigment
_____ 39. main product of photosynthesis
_____ 40. process in which chemical energy, instead of sunlight, is used to make “food”
_____ 41. process in which sunlight is used to make “food”
_____ 42. sac-like membranes that make up the grana within the chloroplast
_____ 43. organelle of photosynthesis
_____ 44. space outside the thylakoid membranes within the chloroplast
_____ 45. energy carrying molecule
_____ 46. series of electron-transport molecules, which pass electrons from molecule to molecule
_____ 47. groups of molecules where sunlight is absorbed during the light reactions
_____ 48. stage of photosynthesis in which the energy from sunlight is stored in ATP and NADPH
_____ 49. stage of photosynthesis in which glucose is made

True or False:

_____ 50. Photosynthesis provides almost all of the energy used by living things on Earth.
_____ 51. Earth’s oxygen comes from photosynthesis.
_____ 52. In photosynthesis, the Calvin cycle comes before the light reactions.
_____ 53. ATP and NADPH are the reactants of the light reactions.
_____ 54. Electron transport occurs in the thylakoid membranes.
_____ 55. All cells have chloroplasts.
_____ 56. During the Calvin cycle, NADPH and ATP are used to make glucose.
_____ 57. Photons of sunlight can excite and energize electrons.
_____ 58. A chemiosmotic gradient causes hydrogen ions to flow across the thylakoid membrane into the stroma.
_____ 59. Like photosynthesis, chemosynthesis also relies on sunlight.
_____ 60. Two turns of the Calvin cycle produce two molecules of glucose.
_____ 61. The Calvin cycle takes place in the stroma surrounding the thylakoid membranes of the chloroplast.
_____ 62. During the light reactions, water molecules are made.
_____ 63. Light is absorbed by photosystems in the thylakoid membranes of chloroplasts.

_____ 64. Both stages of photosynthesis need sunlight to proceed.

_____ 65. Plants gather energy with light-absorbing molecules called pigments.
_____ 66. During the light-dependent reactions, plants use the energy in ATP and NADPH to build high-energy sugars.
_____ 67. C6H12O6 + 6O2 → 6CO2 + 6H2O is the chemical reaction of photosynthesis.
_____ 68. Glucose is a carbohydrate that stores chemical energy in a concentrated and stable form.
_____ 69. Only autotrophs can perform photosynthesis.
_____ 70. Only four types of organisms — plants, algae, fungi and some bacteria — can make food through
photosynthesis.
_____ 71. Photosynthetic animals are autotrophs.
_____ 72. Autotrophs are producers

Multiple Choice:

73. In a typical plant, all of the following factors are necessary for photosynthesis EXCEPT

a. chlorophyll. b. light. c. oxygen. d. water.

74. Which of the following correctly summarizes the process of photosynthesis?
a. H2O + CO2 light sugars + O2
b. sugars + O2 light H2O + CO2
c. H2O + O2 light sugars + CO2
d. sugars + CO2 light H2O + O2

75. Plants get the energy they need for photosynthesis by absorbing

a. high-energy sugars. b. chlorophyll b. c. chlorophyll a. d. energy from the sun.

76. Most plants appear green because chlorophyll b. absorbs violet light. d. does not absorb violet light.
a. absorbs green light. c. does not absorb green light.

77. The stroma is the region outside the

a. thylakoids. b. plant cells. c. chloroplasts. d. all of the above

78. Where in the chloroplast is chlorophyll found?
a. in the ATP
b. in the stroma
c. in the thylakoid membrane
d. in the thylakoid space

79. What is the function of NADP+ in photosynthesis?

a. electron carrier b. high-energy sugar c. photosystem d. pigment

80. Photosynthesis uses sunlight to convert water and carbon dioxide into
a. oxygen and carbon.
b. high-energy sugars and proteins.
c. ATP and oxygen.
d. oxygen and high-energy sugars.

81. Where do the light-dependent reactions take place?
a. in the stroma of the chloroplast
b. within the mitochondria membranes
c. within the thylakoid membranes
d. in the outer membrane of the chloroplasts

82. What are the products of the light-dependent reactions?
a. oxygen gas and glucose
b. ATP, NADPH, and oxygen gas
c. ATP, carbon dioxide gas, and NADPH
d. carbon dioxide gas, oxygen gas, and NADPH

83. Where are photosystems I and II found?

a. in the stroma b. in the Calvin cycle. c. in the thylakoid membrane d. in the cell membrane

84. Which of the following activities happens within the stroma?
a. Photosystem I absorbs light.
b. ATP synthase produces ATP.
c. The Calvin cycle produces sugars.
d. Electrons move through the electron transport chain.

85. The Calvin cycle is another name for the
a. light-independent reactions. c. photosynthesis reaction.
b. light-dependent reactions. d. electron transport chain.

86. Photosynthesis
a. uses the energy in sunlight to make food.
b. uses the glucose in sunlight to make food.
c. uses the energy in sunlight to make ATP.
d. breaks down glucose to form ATP.

87. Photosynthesis can be described as the process that
a. uses carbon dioxide and water, in the presence of sunlight, to produce food (glucose) and oxygen.
b. uses glucose and oxygen to produce energy for the cell (ATP), releasing carbon dioxide and water.
c. uses glucose and oxygen, in the presence of sunlight, to make ATP.
d. uses carbon dioxide and water, in the presence of sunlight, to produce ATP and oxygen.

88. The correct sequence of events in the light reactions is
a. absorption of sunlight, electrons flow down the electron transport chain, ATP is made, NADPH is made.
b. absorption of sunlight, splitting of water, electrons flow down the electron transport chain, ATP is made.
c. electrons flow down the electron transport chain, NADPH is made, ATP is made, water is split.
d. absorption of sunlight, electrons flow down the electron transport chain, NADPH is made, water is split.

89. The Calvin cycle occurs
a. in the granum of the thylakoid membranes of the chloroplast.
b. in the stroma surrounding the inner membrane of the chloroplast.
c. in the stroma surrounding the thylakoid membranes of the chloroplast.
d. in the granum inside the inner membrane of the chloroplast.

90. By the end of the light reactions, energy from sunlight
a. has been stored in chemical bonds of NADPH and ATP.
b. has been transferred to glucose.
c. has entered the Calvin cycle.
d. is ready for use in the cell.

91. Essentially, the oxygen we breathe is
a. necessary for the light reactions to proceed.
b. a waste product of photosynthesis.
c. a reactant of the Calvin cycle.
d. essential for the homeostasis of the plant cell.

92. Which of the following is NOT produced in the light-dependent reactions of photosynthesis?

a. NADPH b. sugars c. hydrogen ions d. ATP

93. The function of chlorophyll is
a. to protect a plant from losing water.
b. to help plants absorb oxygen.
c. to protect the plant cell.
d. to capture energy from the sun.

94. Circle the letters of the regions of the visible spectrum in which chlorophyll absorbs light very well.

a. blue-violet region b. green region c. red region d. yellow region

95. Which reactions change the energy of sunlight to energy-rich carriers?

a. light-dependent reactions b. light-independent reactions

96. Circle the letter of the carrier molecule involved in photosynthesis.

a. H2O c. CO2 b. NADP+ d. O2

97. Circle the letter of each sentence that is true about the light-dependent reactions.
a. High-energy electrons move through the electron transport chain from photosystem II to photosystem I.
b. Photosynthesis begins when pigments in photosystem I absorb light.
c. The difference in charges across the thylakoid membrane provides the energy to make ATP.
d. Pigments in photosystem I use energy from light to reenergize electrons.

98. Circle the letter of each sentence that is true about the light-dependent reactions.
a. They convert ADP into ATP.
b. They produce oxygen gas.
c. They convert oxygen into carbon dioxide.
d. They convert NADP+ into NADPH.

99. Where do the light-dependent reactions occur? Circle the correct answer.

a. thylakoids b. stroma

100. Where do the light-independent reactions occur? Circle the correct answer.

a. thylakoids b. stroma

Short Answer Questions:

101. Where does photosynthesis take place?
102. Why do the leaves of some trees change colors in autumn?
103. How is ATP made during photosynthesis?
104. What are CAM plants?
105. Explain the role of electron carriers in photosynthesis.
106. Why is water “split” during the light reactions?
107. What is an electron transport chain? What is its role during these light reactions?
108. How is ATP made during the light reactions?
109. How is energy used in a cell?
110. When a cell has energy available, how can it store small amounts of that energy?

111. For what purpose do the characteristics of ATP make it exceptionally useful to all types of cells?
112. Why is it efficient for cells to keep only a small supply of ATP on hand?
113. What does photosynthesis require in addition to water and carbon dioxide?
114. What is a granum?
115. What are the two stages of photosynthesis called?
116. When sunlight excites electrons in chlorophyll, how do the electrons change?
117. What is a carrier molecule?
118. How does NADP+ become NADPH?
119. How does ATP synthase produce ATP?
120. What does the Calvin cycle use to produce high-energy sugars?
121. Why are the reactions of the Calvin cycle also called the light-independent reactions?

Critical Thinking:

122. Could we live without photosynthesis? Why? Explain your answer.

123. What would happen if the process of photosynthesis became disrupted, i.e., loss of trees due to deforestation
(cutting down forests), too much carbon dioxide due to burning non-renewable sources of energy (oil, gasoline, coal)
and wood?)

124. Is there anything human beings can due to decrease the amount of carbon dioxide (greenhouse gas) released into
Earth’s atmosphere? Why is this important?