photosynthesis

1. DO NOW 10 min
• On a sticky note write down you definition
for each of the terms listed on the board
and place your answer underneath each
heading.
• Discuss with neighbor your answers and
why you chose them
• ATP, autotroph, heterotroph, photosynthesis &
cellular respiration.

2. Chapter Outline (Ch. 8)
I. Photosynthesis overview
A. Purpose
B. Location
II. The light vs. the “dark” reaction
III. Chloroplasts pigments
A. Light absorption
B. Types
IV. Light reactions
A. Photosystems
B. Photophosphorylation
V. The light independent reaction (“dark” reaction)
A. Carbon “fixation”
B. Reduction
C. Regeneration
VI. Alternative plants

3. • Almost all plants are photosynthetic autotrophs, as
are some bacteria and protists
– Autotrophs generate their own organic matter through
photosynthesis
– Sunlight energy is transformed to energy stored in the
form of chemical bonds
(a) Mosses, ferns, and
flowering plants
(b) Kelp
(c) Euglena (d) Cyanobacteria
THE BASICS OF PHOTOSYNTHESIS

4. Energy can be transformed from one form
to another
FREE ENERGY
(available for work)
vs.
HEAT
(not available for work)

5. THE FOOD WEB

6. Light Energy Harvested by Plants &
Other Photosynthetic Autotrophs

7. THE SUN: MAIN SOURCE OF
ENERGY FOR LIFE ON EARTH

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

9. Electromagnetic Spectrum and
Visible Light
Gamma
rays X-rays UV
Infrared &
Microwaves Radio waves
Visible light
Wavelength (nm)

10. Sunlight minus absorbed
wavelengths or colors equals
the apparent color of an
object.
The feathers of male cardinals
are loaded with carotenoid
pigments. These pigments
absorb some wavelengths of
light and reflect others.

11. Why are plants green?
Transmitted light

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

13. • Chloroplasts absorb
light energy and
convert it to chemical
energy
Light
Reflected
light
Absorbed
light
Transmitted
light
Chloroplast
THE COLOR OF LIGHT SEEN IS THE
COLOR NOT ABSORBED

14. • Photosynthesis is the process by which autotrophic organisms use
light energy to make sugar and oxygen gas from carbon dioxide and
water
Formula for PHOTOSYNTHESIS
Carbon
dioxide
Water Glucose Oxygen
gas
PHOTOSYNTHESIS
6 CO2 + 6 H2O + light energy → C6H12O6 + 6 O2

15. Redox Reactions
Equation for photosynthesis
6 CO2 + 6 H2O + light energy → C6H12O6 + 6 O2

16. Overall purpose:
Photosynthesis - overview
• photosynthesis –
light chemical energy
• complements
respiration
Energy for all life on
earth ultimately comes
from photosynthesis

17. Photosynthesis – chloroplast recap
Outer membrane
Inner membrane
Thylakoid membrane
Stroma
Thylakoid space
Intermembrane space

18. Photosynthesis - overview
– thylakoid membrane
– thylakoid space
– stroma
• light reactions: • dark reactions:
Light
H2O
Chloroplast
Light
Reactions
NADP+
P
ADP
+
ATP
NADPH
O2
Calvin
Cycle
CO2
[CH2O]
(sugar)

19. • The Calvin cycle makes
sugar from carbon
dioxide
– ATP generated by the light
reactions provides the energy
for sugar synthesis
– The NADPH produced by the
light reactions provides the
electrons for the reduction of
carbon dioxide to glucose
Light
Chloroplast
Light
reactions
Calvin
cycle
NADP
ADP
+ P
• The light reactions
convert solar energy to
chemical energy
• Produce ATP & NADPH
AN OVERVIEW OF PHOTOSYNTHESIS

20. Ted Ed- Photosynthesis
• https://youtu.be/eo5XndJaz-Y

21. Mini Lab:
Observing Chloroplasts
10 points
• I will be showing a series of 3 slides of
cells/organisms containing chloroplasts
• You will create a small table for observations, as well
as creating sketches of the cells

25. Grab a Photosynthesis Packet
• You will find the following worksheets
1. Photosynthesis reading
2. Photosynthesis Worksheets
3. 2 answer sheets for TASK CARDS, kept in class
ONLY
4. This is meant to be completed through
Thursday/Tuesday (next week)

26. You DO
• Answer Analysis questions on mini lab sheet.
Turn in once complete
• Begin Photosynthesis reading.
• Complete “Identify Details”
Highlight/underline the events of each stage
of photosynthesis.
• Answer questions 1-8

27. Pack Up
• Complete reading for
homework
• Begin USA Test Prep

28. DO Now 10 min
• Practice EOC questions Photosynthesis 
• 4 corners
• https://www.usatestprep.com/states/states.php

29. Photosynthesis Part II:
The Calvin Cycle, Environmental
Conditions,
& Preventing Photorespiration

30. Photosynthesis: An Overview
• The net overall equation for photosynthesis is:
• Photosynthesis occurs in 2 “stages”:
1. The Light Reactions (or Light-Dependent
Reactions)
2. The Calvin Cycle (or Light-Independent
Reactions)
30
6 CO2 + 6 H2O C6H12O6 + 6 O2
light
Is photosynthesis an ENDERGONIC
(ender means in) or EXERGONIC
(exer –means out) reaction?

31. Photosynthesis: An Overview
• To follow the energy in photosynthesis,
31
light
light ATP
NADPH
Light
Reactions
thylakoids
Calvin
Cycle
stroma
Organic
compounds
(carbs)

32. Phase 2: The Calvin Cycle
• In the Calvin Cycle, chemical energy (from the light reactions)
and CO2 (from the atmosphere) are used to produce organic
compounds (like glucose).
• The Calvin Cycle occurs in the stroma of chloroplasts.
32
glucose.

33. Phase 2: The Calvin Cycle
• The Calvin Cycle involves the process of carbon fixation.
• This is the process of assimilating carbon from a non-organic
compound (ie. CO2) and incorporating it into an organic compound
(ie. carbohydrates).
33
CARBON FIXATION

34. Phase 2: The Calvin Cycle
ORGANIC
COMPOUND
NADPH
NADP+
ATP
ADP
P
RuBP
CO2

35. Phase 2: The Calvin Cycle
35

36. Phase 2: The Calvin Cycle
Quick recap:
•In the Calvin Cycle, energy and electrons from the
Light Reactions (in the form of ATP and NADPH)
and carbon dioxide from the atmosphere are used
to produce organic compounds.
•The Calvin Cycle occurs in the stroma inside the
chloroplasts (inside the cells…).
•Carbon dioxide, ATP, and NADPH are required
(reactants).
•Organic compounds (sugars) are produced
(products). 36

37. Photosynthesis: A Recap
• So, as a broad overview of photosynthesis,
• The Light Reactions (Phase 1) capture the energy
in sunlight and convert it to chemical energy in the
form of ATP and NADPH through the use of
photosystems, electron transport chains, and
chemiosmosis.
• The Calvin Cycle (Phase 2) uses the energy
transformed by the light reactions along with
carbon dioxide to produce organic compounds.
37

38. Cellular Respiration:
(Exergonic)
Photosynthesis:
(Endergonic)
Cellular Respiration vs. Photosynthesis

39. Photosynthesis: A Recap
39
Based on this equation,
how could the rate of
photosynthesis be
measured?
The photosynthetic equation:
light
Excites
electrons
during the
light
reactions
6 H2O
Split during the
light reactions
to replace
electrons lost
from PSII
6 CO2
Provides the carbon to
produce organic
compounds during the
Calvin Cycle
Produced as a
byproduct of the
splitting of
water during the
light reactions
6 O2 C6H12O6
The organic compound
ultimately produced
during the Calvin Cycle

40. Ted Ed Calvin Cycle
• https://www.youtube.com/watch?v=0UzMaoaXKa
M

41. You DO 20 min
• Complete Reading Pages highlighting & #1-8
• Begin Section 2 Worksheet using highlighted
reading or textbook pages 222-227
• Use your group to assist you if needed.
• I will be rotating around to each group as
needed.
• Finished? Begin working on Task Cards located
in the baskets 

42. Review Video
• https://www.hhmi.org/biointeractive/photosynthesi
s
• Watch video, answer questions on study guide

43. You DO 25 min
• Complete Photosynthesis packet
1. Photosynthesis reading
2. Photosynthesis Worksheets
3. Photosynthesis task cards answer sheet completed
4. Photosynthesis study guide
• Small group rotations
• Usa test prep if finished