1. Photosynthesis (Chapter 8)
To make
With light

2. The purpose of photosynthesis is to produce food & oxygen
ATP
The purpose of photosynthesis is to produce food & oxygen

3. Energy & Life
Overview
The cell process identified with energy production is photosynthesis.
Plants use solar energy to convert water & carbon dioxide into high energy sugars (food) & oxygen.

4. Energy & Life
Organisms that can make their own food from the sun are called autotrophs
What does autotroph mean?
Auto = self, troph = nutrition

5. Energy & Life
Organisms that can not use the sun’s energy to make food are called heterotrophs. They obtain energy from food they eat.
Herbivore - Impalas
Carniovore - Leopard

6. Chemical Energy & ATP
Cells use adenosine triphosphate, abbreviated ATP to store & release energy.
ATP is used by all types of cells as their basic energy source.

7. ribose (a 5-carbon sugar) 3 phosphate groups
ATP consists of:
adenine
ribose (a 5-carbon sugar)
3 phosphate groups
3 Phosphate groups
Adenine
Ribose
ATP is used by all types of cells as their basic energy source.
ATP

8. Adenosine Triphosphate (ATP) Adenosine Diphosphate (ADP) + Phosphate
Storing Energy
ADP has two phosphate groups instead of three.
A cell can store small amounts of energy by adding a phosphate group to ADP.
ATP
ADP
Energy +
Energy
Adenosine Triphosphate (ATP)
Adenosine Diphosphate (ADP) + Phosphate
Partially charged battery
Fully charged battery

9. Releasing Energy
Energy stored in ATP is released by breaking the chemical bond between the second and third phosphates.
2 Phosphate groups P
ADP
BLAMO!!

10. ATP energy is used for Lots of stuff like:
active transport across cell membranes.
protein synthesis.
muscle contraction.
ATP is the basic energy source of ALL cells!

11. ATP Movie
2 min video clip

12. Organisms that make their own food are called
autotrophs.
heterotrophs.
decomposers.
consumers.

13. Most autotrophs obtain their energy from
chemicals in the environment.
sunlight.
carbon dioxide in the air.
other producers.

14. How is energy released from ATP?
A phosphate is added.
An adenine is added.
A phosphate is removed.
A ribose is removed.

15. How is it possible for most cells to function with only a small amount of ATP?
Cells do not require ATP for energy.
ATP can be quickly regenerated from ADP and P.
Cells use very small amounts of energy.
ATP stores large amounts of energy.

16. Compared to the energy stored in a molecule of glucose, ATP stores
much more energy.
much less energy.
about the same amount of energy.
more energy sometimes and less at others.

17. Photosynthesis The Photosynthetic Equation: 6CO2 + 6H2O C6H12O6 + 6O2
Light
Light
Carbon
Dioxide
Water
Sugars
Oxygen
B. Photosynthesis uses sunlight to convert water & carbon dioxide into high energy sugars (carbohydrates) & oxygen.

18. Light & Pigments
Plants gather the sun's energy with light-absorbing molecules called pigments.
The main pigment in plants is chlorophyll.
There are two main types of chlorophyll:
chlorophyll a
chlorophyll b

19. special cell organelles called chloroplasts.
Spirogyra sp., a filamentous green alga
Light micrograph of Spirogyra sp., a filamentous green alga (Chlorophyte, Chlorophyta). Spirogyra has characteristic spiral chloroplasts (green bands) within elongated cells of a filament. The chloroplasts contain green chlorophyll pigments and are the site of photosynthesis
Plant leaves are green (usually) because they contain the pigment chlorophyll in
special cell organelles called chloroplasts.

20. What causes a rainbow?? Sunlight contains different wavelengths
of light. Different wavelengths
have different colors & amount of energy.
Rainbows are formed by light passing through water droplets which act as prisms. Red light has the most energy and therefore passes through the prism the fastest and is bent the least. Blue light has the least energy, spends the most time in the prism and is bent the most.
What causes a rainbow??

22. Light and Pigments (cont.)
Chlorophyll absorbs light in the blue-violet and red regions of the visible spectrum.
Photosynthesis requires light and chlorophyll. In the graph above, notice how chlorophyll a absorbs light mostly in the blue-violet and red regions of the visible spectrum, whereas chlorophyll b absorbs light in the blue and red regions of the visible spectrum.

23. Chlorophyll reflects light in the green region of the spectrum, which is why plants look green.
Photosynthesis requires light and chlorophyll. In the graph above, notice how chlorophyll a absorbs light mostly in the blue-violet and red regions of the visible spectrum, whereas chlorophyll b absorbs light in the blue and red regions of the visible spectrum.

24. Chlorophyll absorbs light energy & the energy is transferred to electrons in the chlorophyll molecule. Raising the electrons energy.
These high-energy electrons are what make photosynthesis work.

25. Plants use the sugars produced in photosynthesis to make
oxygen.
Sugars (starches, carbohydrates).
carbon dioxide.
protein.

26. The raw materials required for plants to carry out photosynthesis are
carbon dioxide and oxygen.
oxygen and sugars.
carbon dioxide and water.
oxygen and water.

27. The principal pigment in plants is
chloroplast.
chlorophyll.
carotene.
carbohydrate.

28. The colors of light that are absorbed by chlorophylls are
green and yellow.
green, blue, and violet.
blue, violet, and red.
red and yellow.

29. Photosynthesis Reactions
The chloroplast
Photosynthesis takes place inside the chloroplasts of plants & algae.

30. Chloroplasts of plants & algae.

31. Chloroplasts contain thylakoids—saclike photosynthetic membranes.
Single
thylakoid
Stroma
Chloroplast

32. Thylakoid membrane organize chlorophyll into clusters called photosystems, which collect light.
Chloroplast

33. Photosynthetic reactions
There are two types of photosynthesis reactions:
Light-dependent reactions take place in the thylakoid membranes.
Calvin cycle (Light-independent) reactions takes place in the stroma (outside the thylakoid membranes).

34. Light-Dependent Reactions

35. Light- dependent reactions
H2O
CO2
Light
NADP+
ADP + P
Light- dependent reactions
Calvin Cycle
Calvin cycle
The process of photosynthesis includes the light-dependent reactions as well as the Calvin cycle.
Chloroplast O2
Sugars

36. Light-Dependent Reactions (fig 8-10)
Produce: Oxygen, ATP, & NADPH (electron carrier).
ATP synthase
+ O2
2H2O
The light-dependent reactions use energy from sunlight to produce ATP, NADPH, and oxygen.
ADP
2 NADP+ 2 2
NADPH

37. Light-dependent steps
Reactions occur in the thylakoid membranes of chloroplasts
Light is absorbed by chlorophyll molecules in the thylakoid membrane.
Thylakoid
membrane
Stroma
Chloroplast

38. Light-dependent Steps (Fig 8-10)
Water is broken down into
hydrogen ions
oxygen atoms – we breath
energized electrons
Inner
Thylakoid
space
e- carriers
+ O2
2H2O
Thylakoid
Memebrane
Stroma
Chlorophyll

39. Light-dependent Steps
Electrons move through the electron transport chain & carry H+ ions from the stroma into the inner thylakoid space.
Inner
Thylakoid
space
e- carriers
Thylakoid
Memebrane
ADP
Stroma

40. Light-dependent Steps
NADP+ then picks up these high-energy electrons, along with H+ ions, and becomes NADPH.
+ O2
2H2O
The light-dependent reactions use energy from sunlight to produce ATP, NADPH, and oxygen.
2 NADP+ 2 2
NADPH

41. Light-dependent Steps
Hydrogen ions pass through ATP synthase & convert ADP into ATP.
Inner
Thylakoid
space
Thylakoid
Memebrane
Stroma
ADP

42. Light-Dependent Products
The light-dependent reactions use sunlight, H2O, & CO2 to produce:
Oxygen
Change ADP into ATP
Change NADP+ into high-energy electron carrier NADPH.

43. Calvin Cycle (light-independent reaction)
The Calvin cycle takes place in the stroma of chloroplasts & does not require light.
The Calvin cycle uses CO2 + ATP & NADPH (created in light-dependant reactions) to produce sugars.

44. Light- dependent reactions
Inside a Chloroplast
H2O
CO2
Light
NADP+
ADP + P
Light- dependent reactions
Calvin Cycle
Calvin cycle
The process of photosynthesis includes the light-dependent reactions as well as the Calvin cycle.
Chloroplast O2
Sugars

45. Calvin Cycle (light-independent reaction) Key Steps:
6 CO2 molecules from atmosphere combine with 6 -5 carbon molecules know as RuBP. Product splits into 2 -3carbon molecules.
Energy from ATP & NADPH convert three carbon molecules into higher energy forms known as G3P.
Every 6 cycles produces 2 three carbon molecules which are used to create sugars, lipids, other compounds.

46. 5-Carbon Molecules Regenerated Sugars and other compounds
Calvin Cycle fig. 8-11 12
12 ADP
6 ADP 12
NADPH 6
12 NADP+
5-Carbon Molecules Regenerated
Sugars and other compounds

47. Photosynthesis
1 Min 30 sec video clip

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

49. What are the products of photosynthesis?
ATP
What are the products of photosynthesis?

50. What are the raw materials of photosynthesis?
ATP
What are the raw materials of photosynthesis?

51. What is the energy source of photosynthesis?
ATP
What is the energy source of photosynthesis?

52. In plants, photosynthesis takes place inside the
thylakoids.
chloroplasts.
photosystems.
chlorophyll.

53. Energy to make ATP in the chloroplast comes most directly from
hydrogen ions flowing through an enzyme in the thylakoid membrane.
transfer of a phosphate from ADP.
electrons moving through the electron transport chain.
electrons transferred directly from NADPH.

54. NADPH is produced in light-dependent reactions and carries energy in the form of
ATP.
high-energy electrons.
low-energy electrons.
ADP.

55. What is another name for the Calvin cycle?
light-dependent reactions
light-independent reactions
electron transport chain
photosynthesis