1. Understanding Photosynthesis Chapter 8 Academic Biology

2. Did you know ?

3. Research into PHOTOSYNTHESIS began centuries ago with this
simple question:
When a tiny seed grows into a
huge plant, where does all the
“new plant” come from?

4. EXPERIMENTS TO FIND OUT
a Belgian physician ___________________ determined the mass of a pot of dry soil
and a small seedling.
Jan Van Helmont
Then he planted the seedling in the pot and watered
it regularly. At the end of 5 years the _____________
__________about 75 kg, but the mass of the _________ was almost ________________.
seedling had
gained
soil unchanged
He decided the “increase in plant” had to come from
the ________… that was the only thing he had added!
WATER

5. EXPERIMENTS TO FIND OUT
Van Helmont didn’t realize
the major contribution to
the mass of his tree
was something he
couldn’t see…
__________________ from the air.
carbon dioxide
Plants use _______ and ______ dioxide to make ___________________
water
carbon
Carbohydrates

6. EXPERIMENTS TO FIND OUT
1771- An English minister,
_________________________,
discovered that a flame burning
in a closed jar would die out.
If he placed a __________ in the
jar and allowed a few days to
pass, the candle could be lit again.
Joseph Priestley
live plant
The plant produced something
“required for burning” that the candle used up
OXYGEN
We now know it was …____________

7. EXPERIMENTS TO FIND OUT
1779
Dutch scientist ________________________
showed Priestley’s plant experiment only
worked if the plant was exposed to _________________ !
Jan Ingenhousz
light

8. EXPERIMENTS TO FIND OUT
1961- American chemist ________________________
received the Nobel prize for
figuring out the
chemical _______________
used by plants to make sugar
Melvin Calvin
pathway

9. THE BIG PICTURE → These experiments led to work by later
scientists who finally discovered that in the
presence of light, plants transform CO2 and water
into carbohydrates and release oxygen.
Carbon dioxide
WATER
Sugars
Oxygen
_____________ + ____________ _______________ + ____________
6 CO2
6 H2O →
C6H12O6
6 O2
_____________ + ____________ _______________ + ____________

10. chlorophyll light energy In addition to water and carbon dioxide,
__________________
and
are needed for photosynthesis to happen.
chlorophyll
light energy

11. Photosynthesis consumed
____________________ involves a complex series of chemical reactions, in which the product of one reaction is _____________ by the next reaction.
consumed
Product Y
Reaction 1 →
Product → X
Reaction 2 →
A series of reactions linked in this way is
referred to as a __________________________
biochemical pathway

12. See a video about PHOTOSYNTHESIS 8B

13. PHOTOSYNTHESIS
LIGHT ENERGY
6CO2 + 6H2O
C6H12O6 + 6O2

14. Did you know ?

16. colors Visible light is made up of many different
_______________of light
Your eyes “see”
different sizes of
waves as different
___________
wavelengths
colors

17. Myth:
Many people think that plants are green because they absorb and use green light in photosynthesis,
BUT
Image from:

18. BUT… We “see” reflected light
Light wavelengths that are ___________
off of objects bounce back to our eyes .
That is the ___________ we “see”
REFLECTED
COLOR
Image modified from:

19. absorbs ALL except BLUE reflected
This book “looks BLUE” because the dye in
this cover _______________ of the
wavelengths of light _________ blue.
_______ light is
____________ to your eyes and it
looks BLUE
absorbs ALL
except
BLUE
reflected

20. except red reflected The dye in this T shirt absorbs all of the
colors __________________________
Red wavelengths are
_________________ to
your eyes and the
shirt looks RED
except red
reflected
GO CATS!

21. absorbs ALL ENERGY Objects “look BLACK” because black
dye ________________ of the
wavelengths of light.
When wavelengths are absorbed so is
the_____________ of the wave.
That is why wearing a black T-shirt in the summer feels warmer than wearing
a white t-shirt.
absorbs ALL
ENERGY

22. The dye in white objects _____________ of the wavelengths of light.
_______ energy is ABSORBED
so wearing white
clothing is “cooler”.
REFLECTS ALL
LITTLE

23. Which wavelengths of light are these Flowers REFLECTING?
yellow
Purple & yellow
Images by: VanderWal

24. Which wavelengths of light do these LEAVES reflect? green
So green leaves ____________ the
green wavelength
of light.
REFLECT
Image by: VanderWal

25. Plants gather the sun’s energy with light absorbing molecules called ___________.
pigments
By: VanderWal

26. (These look yellow, orange, and red) CHLOROPHYLL
The main energy
absorbing molecule
in green plants is
___________________
_________________
are plant pigments too.
(These look yellow, orange, and red)
CHLOROPHYLL
CAROTENOIDS

27. GREEN leaves have BOTH chlorophyll AND carotenoids __________________
but the huge amount of chlorophyll ______
the other colors and
leaves usually
look green
ALL THE TIME
hides

28. In ______, chlorophyll production slows as the trees shut down and photosynthesis stops for winter.
FALL

29. carotinoid colors that are usually _______ by chlorophyll
Then we can see the
carotinoid colors that are usually _______ by chlorophyll
HIDDEN

30. There are two types of chlorophyll
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There are two types of chlorophyll
__________________ & ___________________
Chlorophyll a
Chlorophyll b
Absorption of Light by
Chlorophyll a and Chlorophyll b
Chlorophyll a
absorbs the
_____ & ________
wavelengths best.
It absorbs very
little ______ light.
violet
red
Chlorophyll b
Chlorophyll a
red
Blue

31. There are two types of chlorophyll
© Pearson Education, Inc. Publishing asPearson Prentice-Hall. All rights reserved.
There are two types of chlorophyll
__________________ & ___________________
Chlorophyll a
Chlorophyll b
Absorption of Light by
Chlorophyll a and Chlorophyll b
Chlorophyll b
absorbs some
______light and
even more
_________ light.
red
Chlorophyll b
Chlorophyll a
Blue-violet
red

32. NEITHER KIND OF CHLOROPHYLL IS VERY GOOD AT ABSORBING _________ LIGHT!
© Pearson Education, Inc. Publishing asPearson Prentice-Hall. All rights reserved.
Absorption of Light by
Chlorophyll a and Chlorophyll b
NEITHER KIND OF CHLOROPHYLL IS VERY GOOD AT ABSORBING _________ LIGHT!
Chlorophyll b
Chlorophyll a
GREEN
red

33. That’s why leaves LOOK GREEN…..
That’s why leaves LOOK GREEN…..
Chlorophyll doesn’t absorb….
it ___________ GREEN light!
REFLECTS

34. That’s why plant have other pigments (like carotenoids)
That’s why plant have other pigments (like carotenoids). They help _________ some wavelengths chlorophyll _______; so the plant can __________ of the sun’s energy.
ABSORB
DOESN’T
USE MORE

35. SO WHAT WAVELENGTHS ARE BEST FOR PHOTOSYNTHESIS?
© Pearson Education, Inc. Publishing asPearson Prentice-Hall. All rights reserved.
Absorption of Light by
Chlorophyll a and Chlorophyll b
THE ONES CHLOROPHYLL ABSORBS
THE BEST
________ and
_______________
Chlorophyll b
Chlorophyll a
red
Blue-violet

36. Pearson Education Inc, Pusblishing as Pearson Prentice Hall
Because light is a form of ___________, any molecule that absorbs light also ___________the energy from the light.
ENERGY
ABSORBS

37. ENERGY & ELECTRONS When chlorophyll absorbs light, the
When chlorophyll
absorbs light, the
energy is transferred
to electrons in the
chlorophyll molecule.
HIGH ENERGY ____________
make photosynthesis work!
ELECTRONS

38. Any Questions ?

39. Where does Photosynthesis happen?

40. PHOTOSYNTHESIS HAPPENS IN CHLOROPLASTS
THYLAKOIDS
= sac-like
photosynthetic = stack of thylakoids
membranes
inside chloroplast
GRANUM (pl. grana)
Image from BIOLOGY by Miller and Levine; Prentice Hall Publishing©2006

41. SPACES
THYLAKOID SPACE
STROMA
Gel-filled space inside chloroplast surrounding
thylakoid sac
Gel-filled space
Inside the
thylakoid
sac
cytoplasm
Gel-filled space OUTSIDE chloroplast but inside the cell membrane

42. PHOTOSYNTHESIS HAPPENS IN CHLOROPLASTS
Proteins that are part of the thylakoid
membrane organize
________________________________ into clusters called _____________________
Light absorbing PIGMENTS
PHOTOSYSTEMS

43. LIVING THINGS NEED ENERGY CARRIERS
Molecule that carries
= _______
Molecule that carries HIGH ENERGY ELECTRONS
= ___________
ATP
NADP+
Images by Riedell

44. HIGH ENERGY ELECTRONS require a special carrier, too
Frying pan image from: BIOLOGY by Miller and Levine; Prentice Hall Publishing©2006
HIGH ENERGY ELECTRONS require a special carrier, too
____________ is one
of the carriers that
cells use to transport
high energy electrons.
NADP+
________ + _____ + _____ → ____________
2 e- H+
_______= nicotinamide adenine dinucleotide phosphate

45. PHOTOSYNTHESIS Light-Dependent Reaction Oxygen Light & Water
ATP
NADPH
Light-Independent
Reactions

46. LIGHT-DEPENDENT REACTIONS
INSIDE THYLAKOID SPACE
ATP SYNTHASE ↓
PHOTOSYSTEM II ↓
ELECTRON TRANSPORT SYSTEM ↓
PHOTOSYSTEM I
OUTSIDE THYLAKOID IN STROMA
Image modified from: Pearson Education Inc; Publishing as Pearson Prentice Hall

47. ↓ ↓ WHY DOES PHOTOSYSTEM II COME BEFORE PHOTOSYSTEM I?
It was discovered and named 1st
PHOTOSYSTEM II ↓ ↓
PHOTOSYSTEM I
Image modified from: Pearson Education Inc; Publishing as Pearson Prentice Hall

48. See a video clip about the LIGHT-DEPENDENT REACTION (Part 2) 8D

49. REMEMBER Molecules move automatically from “where there’s high [ ]”
to “where there’s low [ ]”
Animatioin from:

50. REMEMBER
Diffusion happens anytime there is a difference in concentration in one place compared to another
= ________________________
CONCENTRATION GRADIENT

51. REMEMBER Diffusion can happen across membranes TOO
…as long as membrane will let molecule through

52. LIGHT-DEPENDENT REACTIONS
SEE A MOVIE ATP SYNTHASE IN ACTION
See an animation about the
ELECTRON TRANSPORT CHAIN

53. LIGHT DEPENDENT REACTION
Requires ______________
Molecules are part of ________________
Made up of __________________
connected by ______________________
& ___________________
Uses light energy to change
ADP + P → _______
NADP+ + 2e- + H + → _________
Breaks apart ______ molecules and releases _____________
LIGHT
THYLAKOID membranes
PHOTOSYSTEMS II & I
ELECTRON TRANSPORT CHAIN
ATP SYNTHASE
ATP
NADPH
H20
oxygen

54. PHOTOSYNTHESIS Light-Dependent Reaction Light & Water Oxygen
ATP
NADPH
C6H12O6
Carbon Dioxide
Light-Independent Reactions
CALVIN CYCLE

55. PHOTOSYNTHESIS OVERVIEW
Pearson Education Inc; Publishing as Prentice Hall

56. Calvin Cycle CO2 Enters the Cycle Energy Input 5-Carbon Molecules
Regenerated
6-Carbon Sugar
Produced
See Calvin cycle animation
Sugars and other compounds

57. CALVIN CYCLE ____________ require ____________
(also called _________________________)
____________ require ____________
Happens in _________ between thylakoids
NADPH donates _______________
ATP donates _________________
CO2 donates ______________
to make __________
LIGHT INDEPENDENT
DOES NOT
LIGHT
STROMA
Hydrogen + electrons
ENERGY
Carbon & oxygen
GLUCOSE

58. Factors that Affect Photosynthesis
AMOUNT OF WATER
____________________
Water is one of the raw materials needed, so
A shortage of water can ________________
photosynthesis
slow or stop
Desert plants and conifers
that live in dry conditions
have a waxy coating on
their leaves to prevent
water loss.

59. Factors that Affect Photosynthesis
TEMPERATURE
Photosynthesis enzymes function best between 0° C - 35° C
At temperatures above or below this range, photosynthesis will slow or stop
Conifers in winter may carry out
photosynthesis only occasionally

60. Factors that Affect Photosynthesis
LIGHT INTENSITY
____________________
More light increases rate of photosynthesis
up to a certain level until plant reaches its
maximum rate of photosynthesis

61. THE BIG PICTURE sugars PHOTOSYNTHESIS provides
the _____________ we breathe
and the __________
heterotrophs (like us)
consume to survive
OXYGEN
sugars
Carbon dioxide
Sugars
WATER
Oxygen
_____________ + ____________ _______________ + ____________

62. Concept Map Photosynthesis includes takes place in uses use
take place in
to produce of
to produce

63. Concept Map Photosynthesis Light- dependent reactions Calvin cycle
Section 8-3
Photosynthesis
includes
Light-
dependent
reactions
Calvin cycle
takes place in
uses
use
take place in
Thylakoid
membranes
Stroma
NADPH
ATP
Energy from
sunlight
to produce of
to produce
ATP
NADPH O2
Chloroplasts
High-energy
sugars