Transcript Photosynthesis
Photosynthesis
The Photosynthesis Song http://www.youtube.com/watch?v=C1_uez5W X1o Intro Video – http://www.youtube.com/watch?v=zEgIO9Kq 2_Y
Photosynthesis
Photosynthesis the Movie http://vcell.ndsu.nodak.edu/animations/photos ynthesis/movie.htm
Objectives
1.
2.
3.
4.
Summarize how energy is captured from sunlight during the light dependent reactions of photosynthesis.
Analyze the function of electron transport chains during the light dependent reactions of photosynthesis.
Relate the Calvin cycle to carbon dioxide fixation in photosynthesis.
Identify three environmental factors that affect the rate of photosynthesis.
Stages of Photosynthesis
Stage 1 Light-dependent reaction
Chlorophyll pigments
capture light energy Stage 2 Light-dependent reaction
Light energy converted to chemical energy. Production of ATP and NADPH
Stage 3 Light-independent reaction
Reduction of CO 2 to glucose: using ATP + NADPH + H + to
synthesize
organic compounds (glucose) from CO 2 (carbon fixation); process called
Calvin cycle
; © Teachable and Louise Edgeworth. Some rights reserved. http://teachable.net/res.asp?r=6615
Thylakoid membranes Stroma
The Dark Side
You just made a bunch of ATP and NADPH from the light reactions.
You now use these electrons and energy to put a bunch of carbons together to make glucose – this is the job of the Calvin cycle.
2.
3.
1.
The Calvin cycle can be broken down into three phases:
Carbon fixation
– Putting carbons together.
Reduction reactions
– Adding electrons & energy.
Regeneration of RuBP
is a cycle after all.
– Getting back to the start – it
The Calvin Cycle!
What is it?
The Calvin Cycle uses ATP and NADPH from the light-dependent reactions and CO 2 from the air to make high-energy sugars (glucose)!
Glucose
Where does the Calvin Cycle occur?
The Calvin Cycle occurs in the stroma of the chloroplast.
What parts of the photosynthesis equation are involved in the Calvin Cycle?
CO
2
is broken down to create
glucose (C
6
H
12
O
6
)
C 6 H 12 O 6
Steps of the Calvin Cycle
Calvin Cycle – Carbon Fixation 1. Six CO 2 molecules enter the leaf through the stoma and diffuse into the stroma. They are added to a 5 carbon compound (ribulose biphosphate (RuBP)) by an enzyme (rubisco – ribulose bisphosphate carboxylase).
Calvin Cycle – Carbon Fixation 2.
They are split into twelve 3 carbon compounds 3.
( 3 phosphoglycerate (PGA)).
Calvin Cycle
– Reduction Reactions 3.
4.
Energy from
ATP is
used to phosphorylate the 3 carbon compounds (PGA) into 1,3 biphosphoglycerate A pair of electrons from
NADPH
reduces the 1,3 biphosphoglycerate to give G3P – glyceraldehyde 3 phosphate., a 3C
Calvin Cycle – Regeneration of RuBP 4. Two of the resulting 3-carbon sugars is used to make organic compounds – including GLUCOSE, starch and sucrose – in which energy is stored for later use by the organism.
Calvin Cycle – Regeneration of RuBP 5. The other ten 3-carbon sugars are used to regenerate the initial 5 carbon compound, (RuBP) thereby completing the cycle. This process consumes 6 molecules of ATP
Review of Calvin Cycle
Where does the Calvin Cycle occur?
In the stroma of the chloroplast!
What goes into the Calvin Cycle?
ATP and NADPH are used for energy CO 2 is broken apart to create C 6 H 12 O 6
Animation of Overview of Photosynthesis
http://wps.prenhall.com/wps/media/objects/ 486/498596/CDA7_1/CDA7_1d/CDA7_1d.
htm
Factors that Affect Photosynthesis 1.
2.
3.
Photosynthesis is directly affected by environmental factors such as: The intensity of light The concentration of carbon dioxide Temperature.
1.
2.
3.
4.
5.
6.
7.
PHOTOSYNTHESIS QUIZ
15 points Where in a plant cell does photosynthesis occur?
What are the 2 stages of photosynthesis and where do they occur?
Why are plants green?
What is the balanced equation for photosynthesis?
What are the reactants and products of the light dependent reactions?
What are the reactants and products of the Calvin Cycle?
What are two reasons we depend on plants for our survival?
Review 1. Summarize
how photosynthetic organisms capture the energy in sunlight.
2. Compare
the roles of water molecules and hydrogen ions in electron transport chains.
3. Describe
the role of the Calvin cycle in photosynthesis.
4. Critical Thinking Organizing Information
Make a table in which you identify the role of each of the following in photosynthesis: light, water, pigments. ATP. NADPH. and carbon dioxide.
5. Critical Thinking Inferring Relationships
What combination of environmental factors affects the rate of photosynthesis?
6. Standardized Test Prep
During photosynthesis, plants store energy in
A
ADP.
B
carbon dioxide.
C
3-carbon sugars.
D
water.