1. PHOTOSYNTHESIS Chapter 8 Pages 201-214
THE LIGHT REACTION

2. What does the word mean? Photo - - - synthesis
"with light putting things together”
Plants use glucose as food for energy and as a building block for growing.
Sunlight energy is transformed to energy stored in the form of chemical bonds. This is a chemical reaction.

3. Plants are energy producers
Like animals, plants need energy to live
unlike animals, plants don’t need to eat food to make that energy
Plants make both FOOD & ENERGY
animals are consumers
plants are producers
Autotrophs make glucose and heterotrophs are consumers of it.

4. PHOTOSYNTHESIS
Autotrophic Process: Plants and plant- like organisms make their energy (glucose) from sunlight.
Stored as carbohydrate in their bodies.
(a) Mosses, ferns, and
flowering plants
(b) Kelp
(c) Euglena
(d) Cyanobacteria

5. Why is Photosynthesis important?
It allows plants to have energy to do work.
Makes organic molecules (glucose) out of inorganic materials (carbon dioxide and water).
It begins all food chains/webs. Thus all life is supported by this process.
It also makes oxygen gas!!

6. Photosynthesis facts continued
Plants gather sunlight with light – absorbing molecules called Chloroplasts.
The main pigment is chlorophyll.
Chlorophyll only absorbs light in certain parts of the visible spectrum.

7. What is the equation for the chemical reaction of photosynthesis?
Six molecules of carbon dioxide react with six molecules of water to form 1 molecule of glucose and six molecules of oxygen.

8. WHY ARE PLANTS GREEN?

9. Different wavelengths of visible light are seen by the human eye as different colors.
Gamma rays
X-rays UV
Infrared
Micro- waves
Radio
waves
Wavelength (nm)
Visible light

10. The feathers of male cardinals are loaded with carotenoid pigments
The feathers of male cardinals are loaded with carotenoid pigments. These pigments absorb some wavelengths of light and reflect others.
Reflected light

11. Why are plants green?
Reflected light
Transmitted light

12. Plant Cells have Green Chloroplasts
The thylakoid membrane of the chloroplast is impregnated with photosynthetic pigments (i.e., chlorophylls, carotenoids).

13. Light
Reflected
light
Absorbed light
Transmitted light
Chloroplast

14. Chloroplast Pigments Chlorophyll a Chlorophyll b Carotenoids
Chloroplasts contain several pigments
Chlorophyll a
Chlorophyll b
Carotenoids
Xanthophyll

15. Chlorophyll b
Chlorophyll a
Absorption of Light by
Chlorophyll a and Chlorophyll b

16. Fall Colors
In addition to the chlorophyll pigments, there are other pigments present.
During the fall, the green chlorophyll pigments are greatly reduced revealing the other pigments.
Carotenoids are pigments that are either red or yellow.

17. Chlorophyll a & b Chl a has a methyl group Chl b has a carbonyl group
Porphyrin ring
delocalized e-
Phytol tail

18. Which color in the spectrum does chlorophyll a absorb the most?
Violet
Blue
Green
Yellow
Orange
Red

19. Which color in the spectrum does chlorophyll b absorb the most?
Violet
Blue
Green
Yellow
Orange
Red

20. Which color in the spectrum does chlorophyll a & b absorb the least?
Violet
Blue
Green
Yellow
Orange
Red

21. The History of Photosynthesis
How do we know plants “make” there food?

22. Jan van Helmont’s Famous Tree Experiment

23. The year was 1642…
“I took an earthen vessel, in which I put 200 pounds of earth that had dried in a furnace,
which I moistened with rainwater, and I implanted therein the trunk or stem of a willow tree, weighing five pounds.
And at length, five years being finished, the tree spring from thence did weigh 169 pounds and about three ounces. …
Lest the dust that flew about should be mingled with the earth, I covered the lip or mouth of the vessel with an iron plate covered with tin and easily passable with many holes. …
I again dried the earth up in the vessel, and there was found the same 200 pounds, wanting about two ounces.”

24. After Before 5 lb Willow 200 lb dirt Day 1 169 lb Willow
199 lb 14 oz dirt
5 years later
3400% Increase % decrease
in weight in weight

25. Questions? What question did van Helmont set out to answer?
How would you explain how the tree gained 164 lbs or 75 Kg in mass?
Jan van Helmont believed that the increase in mass was solely due to the water taken in by the plant. If van Helmont had tested his hypothesis correctly, the plants would not have grown. What is his misconception?

26. Jan van Helmont in short…
Grew a willow tree
Weighed soil before and after
Added only Water
Tree gained 164 lb or 75 Kg
No change in mass of soil
CONCLUSION (partially accurate)… Mass in plant comes from water.
Van Helmont accounts for the “Hydrate” in carbohydrate.

27. John Priestly

28. Part 1 Priestly lit a candle. He then placed a glass jar over it…
…and watched as the flame gradually died out.

29. Part 1 Priestly lit a candle. He then placed a glass jar over it…
…and watched as the flame gradually died out.

30. Priestly reasoned that something in the air was necessary to keep the flame burning.

31. Part 2 Priestly then placed fresh mint leaves underneath the jar
and allowed the
entire setup to sit for
a few days.

32. A few days passed…

33. Part 2 After a few days, Priestly found that he could relight the
candle and it would
burn for a while.

34. Part 2 After a few days, Priestly found that he could relight the
candle and it would
burn for a while.

35. Priestley concluded that the plant had produced the substance required for burning.
What substance was consumed as the candle burned the first time?
Oxygen

36. What must have been added to the jar to enable the candle to burn the second time?
Oxygen

37. Where did this oxygen come from?
The Plant

38. What do you think would happen if Priestly had put the plant and candle back in the jar for a few days then once again tried to light the candle?
the plant would die
the plant would light on fire
the candle would light again
the candle would not light again

39. What does this tell you about plants and oxygen?
plants do not need all the oxygen they take in
plants produce oxygen all the time
plants produce as much oxygen as they need
plants produce oxygen in the presence of light

40. The Other Experiment In another experiment, Priestly put a mouse
under the jar and
waited to see what
would happen.

41. The Other Experiment In another experiment, Priestly put a mouse
under the jar and
waited to see what
would happen.
Sadly, the mouse eventually died.

42. The Other Experiment Later, Priestly put a mouse under the
jar with fresh mint
leaves and waited to
see what would
happen.
To his surprise, both the mouse and plant survived for quite some time.

43. What important substance was produced by the plant?
Oxygen

44. What important substance was produced by the mouse?
Carbon Dioxide

45. Animals use Carbon dioxide
Why were both the plant and the mouse able to survive under the jar?
Plants use Oxygen
Animals use Carbon dioxide

46. In Short…

47. Jan Ingenhousz

48. Jan Ingenhousz Out does Priestly
Led to the discovery that plants need light to produce oxygen
He performed Priestly’s experiment and discovered that the candle only remained

50. What’s going on in the Chloroplasts?

51. Plants Autotrophs: self-producers. Location: 1. Leaves a. stoma
b. mesophyll cells – Plant tissue usually containing chlorophyll, that forms the interior parts of a leaf.
Stoma
Mesophyll
Cell
Chloroplast

52. Stomata (stoma)
Pores in a plant’s cuticle through which water and gases are exchanged between the plant and the atmosphere.
Oxygen
(O2)
Guard Cell
Carbon Dioxide
(CO2)

53. The major parts of a Mesophyll Cell
Nucleus
Cell Wall
Chloroplast
Central Vacuole

54. Chloroplast Organelle where photosynthesis takes place. Stroma
Outer Membrane
Thylakoid
Granum
Inner Membrane

55. Thylakoid
Thylakoid Membrane
Granum
Thylakoid Space

56. PHOTOSYNTHESIS IN CHLOROPLASTS REVIEW
CHLOROPLASTS CONTAIN:
AN OUTER MEMBRANE
HIGH PERMEABILITY
AN INNER MEMBRANE
NEARLY IMPERMEABLE
THE STROMA
AQUEOUS
CONTAINS ENZYMES, DNA, RNA, RIBOSOMES
THE “THYLAKOID”
A MEMBRANEOUS COMPARTMENT
DERIVED FROM INVAGINATIONS OF INNER MEMBRANE
A SINGLE HIGHLY-FOLDED VESICLE
“GRANA” : DISK-LIKE SACS
GRANA ARE CONNECTED BY “STROMAL LAMELLAE”

57. How does Photosynthesis really work?
But first…
TWO OVERVIEWS OF PHOTOSYNTHESIS

58. reactions High-energy sugars
Photosynthesis
includes
Calvin cycle
Light-dependent
reactions
takes place in
uses
use
take place in
Thylakoid
membranes
Stroma
NADPH
ATP
Energy from
sunlight
to produce
to produce
ATP
NADPH O2
Chloroplasts
High-energy
sugars of

59. 6CO2 + 6H2O + sunlight  C6H12O6 + 6O2

60. Redox Reaction
The transfer of one or more electrons from one reactant to another.
Two types:
1. Oxidation
2. Reduction

61. The loss of electrons from a substance. Or the gain of oxygen.
Oxidation Reaction
The loss of electrons from a substance.
Or the gain of oxygen.
Oxidation
glucose
6CO H2O  C6H12O O2

62. The gain of electrons to a substance. Or the loss of oxygen.
Reduction Reaction
The gain of electrons to a substance.
Or the loss of oxygen.
Reduction
glucose
6CO H2O  C6H12O O2

63. ENERGY AND WHAT IT LOOKS LIKE Adenosine Triphosphate

64. Comparison of ADP and ATP to a Battery
Energy
ATP
Adenosine triphosphate (ATP)
Adenosine diphosphate (ADP)
+ 1 Phosphate
Energy
Fully
charged
battery
Partially
charged
battery
See the energy in ATP is stored between the bonds of its phosphate groups.

65. There is too much energy stored in glucose, so its broken down slowly in order not to lose any energy. This energy is stored in ATP.
When a -P group is added to ADP, it will have enough energy to react with other molecules.
Also ATP is a nucleotide.

66. NADPH: Nicotinamide adenine dinucleotide phosphate
Other Batteries
NADPH: Nicotinamide adenine dinucleotide phosphate
fully charged battery (high in energy)
NADP+: Nicotinamide adenine dinucleotide phosphate
weaker battery (low in energy)

67. Transfers energy very quickly Takes longer to get energy out
ATP
Glucose
Short Term
Long Term Storage
Transfers energy very quickly
Takes longer to get energy out
Can’t store energy very long. (breaks down to ADP and loses energy)
Can store energy very well. 1 molecule of glucose can hold 90 times more energy than ATP.

68. Chloroplasts: Sites of Photosynthesis
Occurs in chloroplasts, organelles in certain plants
All green plant parts have chloroplasts and carry out photosynthesis
The leaves have the most chloroplasts
The green color comes from chlorophyll in the chloroplasts
The pigments absorb light energy

69. Steps of Photosynthesis (see diagram)
Two main parts:
1. Light-dependent reaction (light cycle)
2. Light-independent reaction (Calvin Cycle)

71. AKA: light dependent reaction
Light Cycle:
AKA: light dependent reaction
Where: takes place in the membrane of the thylakoid
When: happens anytime a place has water and sunlight
Why: it charges the batteries for use in the next cycle (ATP and NADPH)
What it uses: H2O and sunlight and dead batteries (ADP and NADP+)
What it makes: O2 and charged batteries (ATP and NADPH)

72. Two types of photosystems cooperate in the light reactions
Photon
ATP
mill
Photon
Water-splitting
photosystem
NADPH-producing
photosystem

73. LIGHT LIGHT Purple Goes in Red comes out Black is info INSIDE H+ e-
Chlorophyll
OUTSIDE

74. Calvin cycle: AKA: light- independent cycle, Dark cycle
Where: Takes place in the stroma (liquid) of cholroplast
When: Takes place anytime batteries are charged (day or night)
Why: uses batteries to make sugar, which is stored for later use.
What it uses: CO2 and charged batteries (ATP and NADPH)
What it makes: Sugar (C6H12O6) and dead batteries (ADP and NADP+)

75. Purple Goes in Red comes out
Stroma
liquid
Purple Goes in Red comes out
Black is info
Sugar= C6H12O6

76. Factors Affecting Photosynthesis
a. Shortage of water
b. Temperature: 32oF to 95oF is what enzymes work best at.
c. Light Intensity
d. CO2 concentration

78. What affects the rate of Photosynthesis?

79. Light intensity: as light increases, rate of photosynthesis increases… but this only works so long then it levels out.

80. Carbon Dioxide: As CO2 increases, rate of photosynthesis increases

81. Temperature:
Temperature Low = Rate of photosynthesis low
Temperature Increases = Rate of photosynthesis increases
If temperature too hot, rate drops

82. Photosynthesis lab

83. Questions
Spinach leaves are only one color (green), yet this part of the lab indicated more than one pigment can be found in within the spinach leaves. Explain why?
Use your notes on why leaves change color (and the internet if you need) and try to identify the pigments that are present in your spinach leaf.
Red cabbage leaves are only one main color (red), yet this part of the lab indicated more than one pigment can be found in within the cabbage leaves. Explain why?
Use your notes on why leaves change color (and the internet if you need) and try to identify the pigments that are present in your cabbage leaf.

84. Spinach
Carotene
Xanthophyll
Chlorophyll a
Chlorophyll b

85. Red cabbage
Betacyanin
anthocyanin
Chlorophyll
a and b

86. Comparison Chart of the 2 Cycles

87. What other names does the cycle have?
Light Cycle
Light Dependent Cycle

88. What other names does the cycle have?
Dark Cycle
Light Independent Cycle
Calvin Cycle

89. Where does the cycle run?
Membrane of the Thylakoid

90. Where does the cycle run?
Stroma of the Chloroplasts

91. When can the cycle run?
Any time that there is water and sunlight.

92. When can the cycle run?
Any time that there are charged batteries ATP and ADPH and CO2.

93. Why does the cell need this cycle?
To change:
ADP to ATP
NADP+ to NADPH

94. Why does the cell need this cycle?
To make sugar and other products that the cell needs for life processes.

95. What are the reactants?
Light
Water
ADP
NADP+

96. What are the reactants?
CO2
ATP
NADPH

97. What are the products?
Oxygen (O2)
ATP
NADPH

98. What are the products?
Sugar
ADP
NADP+

99. Other Notes on the Cycle
Photo system 1
Photo system 2
Electron transport chain
Uses sun to charge batteries

100. Other Notes on the Cycle
Carbon fixation
6 turns to make 1 glucose
Can happen in sunlight but does not need it to run.

101. Photosynthesis Worksheets

102. Why do the leaves change color in the fall?

103. 1. What pigment do leaves get their color from?
Chlorophyll a and b

104. 2. What is the function of Chlorophyll?
Absorbs sunlight and uses it to make food (glucose).

105. They move from the leaves to the branches, trunk and roots.
3. When trees are preparing for winter, where do the nutrients move to?
They move from the leaves to the branches, trunk and roots.

106. 4. When the nutrients leave the leaves what happens to the chlorophyll?
It is not made by the leaves any more and current pigment in the leaves disintegrate.

107. 5. How do the pigments come out of hiding?
The dominant pigment… Chlorophyll is gone so other pigments show through.

108. 6. What are the pigments that turn leaves scarlet, wine red and purple?
Anthocyanin

109. 7. How is the color of the leaves on the tree determined?
It is inherited.

110. 8. What factor influences whether these colors are dull or bright?
Weather conditions.

111. 9. How is the most brilliant shade developed in a tree?
Temperatures from 32 to 45 F and limited rain.

112. 10. How do the leaves fall off the branches?
And within a few days or weeks, every leaf on these deciduous trees develops a thin bumpy line of cells that push the leaf, bit by bit, away from the stem. You can't see this without a microscope, but if you looked through one, you'd see those scissors cells lined right up.
The scissor cells are stained red and mark the boundary between the branch (left) and the leaf stalk. 

113. Chapter 8 Photosynthesis Chapter Vocabulary Review

114. 1. Where do autotrophs get energy to produce food?
From the sun and water.
(a) Mosses, ferns, and
flowering plants
(b) Kelp
(c) Euglena
(d) Cyanobacteria

115. 2. How do living things use ATP?
To store and release energy

116. 3. How is one molecule of ATP formed from one molecule of ADP?
When a cell has energy available it stores small amounts of it by adding a phosphate group to ADP.

117. 4. How does a change from ATP to ADP provide an organism with energy?
When ATP is changed to ADP a phosphate group is removed. This removal releases energy in the cell.

118. 5. What are two ways in which cells use the energy provided by ATP?
active transport across cell membranes and muscle contraction

119. Really
Decomposers…
Autotrophs
Heterotrophs

120. H2O
ATP
NADPH

121. NADP+
ADP
CO2

122. _______________________11
_______________________11. Molecule that absorbs light ___________________________12. Produces oxygen gas and converts ADP to ATP _______________________13. the region _______________________14. principal pigment found in plants _______________________15. process by which autotrophs use sunlight to make high-energy sugars
C- pigment
E- light dependent reaction
B- stroma
A- chlorophyll
D- photosynthesis

123. Light
Water
CO2
O2 Gas
Sugar

124. ATP
Large protein that needs 3 phosphate groups to be charged. Quick Energy.

125. Thylakoid
Photosynthetic membrane in the chloroplast where light cycle takes place.

126. NADP+
Carrier molecules transfers high energy e- from chloroplasts to sugars (glucose). This is the low charged form.

127. ATP Synthesis
Protein uses H+ ions to produce ATP. Happens in Thylakoid membrane and it is the high charged form.

128. Calvin Cycle
Energy from ATP and NADPH is used to build high energy sugars such as glucose The cycle runs 6 times to do this.

129. 6. What is the difference between Autotrophs and heterotrophs?
Autotrophs make there own food (glucose) like plants, algae
Heterotrophs get nutrients from eating autotrophs.

130. 7. in which part of photosynthesis is oxygen produced?
Photolysis takes place in photosystem 1. This produces energy by splitting water molecules into gaseous oxygen and hydrogen ions.

131. 8. What is the relationship between pigment and chlorophyll?
pigments absorbs light & chlorophyll is the green pigment in plants.

132. 9. How do the light-dependent reactions differ from the Calvin cycle ?
light-dependent reaction uses energy from the sun to produce ATP & NADPH & oxygen gas (O2).
Calvin cycle does not require light & uses ATP & NADPH for energy to produce glucose

133. 10. What compounds are formed from carbon dioxide in the Calvin cycle.
Monosaccharaides (glucose)
Disaccharides (glucose + Fructose)
Eventually polysaccharides

134. Photosynthesis Reviews

135. Photosynthesis has 3 stages:
Stage 1: absorption of light energy & chlorophyll vibrates and causes water to break apart.
Stage 2: conversion of light energy into chemical energy, temporarily stored in ATP and NADPH
Stage 3: storage of chemical energy in ATP and NADPH powers the formation of organic molecules

136. The light reactions convert solar energy to chemical energy
Produce ATP & NADPH
Light
Chloroplast
NADP
ADP
+ P
Calvin
cycle
Light
reactions
The Calvin cycle makes sugar from carbon dioxide

137. Steps of Photosynthesis
The DARK Reactions= Calvin Cycle
CO2 from atmosphere is joined to H from water molecules (NADPH) to form glucose
Glucose can be converted into other molecules with yummy flavors!