The On-Going Quest for Energy!
i.
1.
The Big Picture
Life needs energy.
2.
To make energy, 3 things are
required:
- sugar (glucose)
- oxygen
- enzymes
I.
A.
O2
Photosynthesis
The Quest for Sugar
1. Plants make their own glucose
(autotrophic)
a. requires energy from sun
b. requires raw materials
1. C, H, O  C6H12O6
6 CO2 + 6 H2O

C6H12O6 + 6
I.
A.
Photosynthesis
The Quest for Sugar
2. Two essential steps:
a. 1st  make energy
b. 2nd  use that energy to
break up
raw materials and
synthesize
glucose
I.
B.
Photosynthesis
How Plants Do It!
1. Light Dependent Reactions
a. light strikes chlorophyll
b. knocks loose some e-’s
c. e- fall down “Electron
Transport
Chain” (like a set of
stairs)
1. each step releases ATP
I.
B.
Photosynthesis
How Plants Do It!
d. ATP used for:
1. carbon fixation
a. breaking C out of
CO2
(making it
more usable)
2. photolysis
a. splitting water
RAW MATERIALS:
SUN
CO2 (air), H2O (ground)
C, O
Light Dependent Reactions
H, O
ATP
e-
e-
e-
e-
Electron Transport Chain
Light
Independent
Reactions
I.
B.
Photosynthesis
How Plants Do It!
2. Light Independent Reactions
a. series of reactions that
reassemble all C’s, H’s,
and O’s into C6H12O6
1. these reactions are
called the Calvin Cycle”
II. ATP
A.
What is it?
1. Adenosine Tri-Phosphate (ATP)
a.
perform
molecule containing readily
available energy to
cellular work
II. ATP
B. How does it work?
1. Releases a burst of energy
when
one P- is broken off
ATPase
Adenosine-P-P-P
Adenosine-P-P
+P
Adenosine-P-P
+P
ATP Synthase
Adenosine-P-P-P
III. Cellular Respiration
A. Handout