Photosynthesis Notes (Chapter 6)
Objectives
a)
b)
c)
d)
Summarize the reactants and products of photosynthesis.
Describe the reactants and products of the light reactions.
Describe the reactants and products of the Calvin Cycle (dark reactions).
Summarize how the light reactions and Calvin cycle work together to create a continuous cycle of
photosynthesis.
Q: Where does the energy come from in each stage of the food chain?
A:
1) _____________________ - Make their own food
2) _____________________ - Cannot make their own food
ATP
a)
The principal chemical compound that cells use to store and release energy is called ATP (adenosine
triphosphate)
b) stores energy in the ___________ between the _______ and _______ phosphate group
c) Q: How is the energy in ATP released?
i) A: _________________________________________________________________________
ATP vs. ADP
3) ATP – has all________ phosphate groups
a) Fully charged battery
b) Brief energy storage
c) Can remove a _________________________________ to release energy and form ADP
4) ADP – has only _______ phosphate groups
a) Partially charged battery
b) Can add a phosphate group to make _________________
5) ATP Availability
a) Most cells only have enough ATP for a ___________________________ of activity. Why?
i) Not good at storing energy over the long term
ii) Glucose stores __________________ the chemical energy of ATP
iii) Cells generate ATP from ADP as needed by using the energy in foods (like glucose)
Photosynthesis
6CO2 + 6H2O + _________________  C6H12O6 + 6O2
The Visible Light Spectrum
6) Pigments
a) Absorb different wavelengths of light (colors)
b) Reflect (transmit) what they do not absorb
c) We see what is ________________________________.
7) _________________________________ - The plant’s principal pigment
a) Absorbs light energy
i) blue-violet
ii) red
Q: Why are leaves green?
A:
__________________________________________________________________________________________
__________________________________________________________________________
8) Light energy
a) Anything that absorbs light also absorbs the energy from that light
b) When chlorophyll absorbs light, much of the energy is transferred to electrons in the chlorophyll
molecule, raising the energy level of these electrons
c) These high-energy electrons make photosynthesis work
Photosynthesis Basics
9) Where does photosynthesis take place? _________________________________________________
10) __________________________________ - Sac-like photosynthetic membranes arranged in stacks
11) _____________________ - Stacks of thylakoids
i) Granum – singular
ii) Grana - plural
12) ______________________________ - The watery region in a chloroplast, outside the thylakoids
i) Similar to the cytoplasm in the cell
Photosynthesis occurs in two parts:
13) Light – dependent reactions
14) Light – independent/Calvin Cycle reactions
ANALYZE THE PICTURE

List the reactants and products for
o The light dependent reactions
 Reactants:
 Products:
 Location where it occurs:
o The Calvin Cycle (light independent) reactions
 Reactants:
 Products:
 Location where it occurs:
Light Dependent Reactions
15) “______________________” part of photosynthesis
a) Reactants:
i) _____________________________________________________________
b) Products:
i) ________________________________________________________________
Q: Where did the Oxygen, produced by the light dependent reactions come from?
A: _______________________________
What you need to know:
16) Where do the light reactions occur?
17) What is needed (reactants)?
18) What is created (products)
Carrier Molecule
19) Compound that can accept a high energy electron and transfer it along with most of its energy to another
molecule
a) Ex.) NADP+ + H  NADPH
The Calvin Cycle


The “___________________________” part of photosynthesis
These reactions don’t require ___________________ therefore these reactions are called Light –
Independent or Dark reactions
20) Reactants:
a) ______________________________________________________________________
21) Products:
a) _______________________________________________________________________
Carbon Fixation
22) The incorporation of __________________________ into ________________________ compounds
a) The Carbon in CO2 is “fixed” into the usable energy form of sugar
b) 6 CO2 molecules will go into the cycle to produce each organic molecule of 6-Carbon sugar. (C6H12O6 )
Factors Affecting Photosynthesis
1.
2.
3.
4.
Not enough water
Temperature
Light intensity
CO2 levels