Cellular Energy
Ch. 8
Regents Biology
Transformation of Energy
 Thermodynamics – the study of the
flow and transformation of energy
 Laws of Thermodynamics:
First Law: The Law of Conservation of
Energy – energy can be converted from
one form to another but cannot be
created or destroyed.
 Second Law – energy cannot be
converted without the loss of usable
energy.

Regents Biology
Metabolism
 Metabolism – a series of chemical
reactions in which the product of one
reaction is the substrate for the next
reaction.
 Catabolic Pathways – break down
larger molecules to make smaller
molecules, releases energy
 Anabolic Pathways – build larger
molecules from smaller molecules,
uses energy
Regents Biology
Product
Reactant
Product
Reactant
Photosynthesis:
Life from Light and Air
Regents Biology
2006-2007
Plants are energy producers
 Like animals, plants need energy to live

unlike animals, plants don’t need to eat
food to make that energy
 Plants make both FOOD & ENERGY
animals are consumers
 plants are producers

Regents Biology
How do plants make energy & food?
 Plants use the energy from the sun
to make ATP energy
 to make sugars

 glucose, sucrose, cellulose, starch, & more
sun
ATP
sugars
Regents Biology
Building plants from sunlight & air
 Photosynthesis



2 separate processes
ENERGY building reactions
 AKA Light reactions
 collect sun energy
 use it to make ATP
SUGAR building reactions
 AKA Calvin cycle
 take the ATP energy
 collect CO2 from air &
H2O from ground
 use all to build sugars
sun
ATP
H2O
+
CO2
sugars
Regents Biology
Photosynthesis
sun
ENERGY
building
reactions
ATP
ADP
SUGAR
building
reactions
H2O
Regents Biology
used immediately
to synthesize sugars
sugar
CO2
Plant structure
 Chloroplasts


double membrane
stroma
 fluid-filled interior


outer membrane
inner membrane
thylakoid sacs
grana stacks
stroma
thylakoid
 Thylakoid membrane
contains



AP Biology
granum
chlorophyll molecules
electron transport chain
ATP synthase
Light Reactions of Photosynthesis
Photosystem II
Photosystem I
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to Calvin Cycle
Electron Transport Chain
ATP
H+
Stroma
Thylakoid
Membrane
ATP Synthase
Photosystem I
Photosystem II
Thylakoid
Space
H+
Split H2O
AP Biology
O2 + H+
From Light reactions to Calvin cycle
 Calvin cycle

chloroplast stroma
 Need products of light reactions to
drive synthesis reactions
stroma
ATP
 NADPH

thylakoid
AP Biology
Quick Quiz!
Photosystem II
 What is the first protein in ETC called?
Thylakoid
 Where does ETC take place? membrane
 What molecule serves as the original



electron donor? H2O
What are the two molecules made in
ETC? NADPH & ATP
Where is the electron deposited at the
end of ETC? NADPH
What is the name of the final protein?
ATP Synthase
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C
C
Calvin cycle
C C C C C
1C
C C C C C
3. Regeneration
C C C C C
of RuBP
RuBP
starch,
sucrose,
cellulose
& more
ribulose bisphosphate
used
to make
glucose
AP Biology
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
CO2
1. Carbon fixation
C C C C C C
5C
3 ATP
3 ADP
C
RuBisCo
ribulose
bisphosphate
carboxylase
C C C C C C
6C
C C C C C C
5C
glyceraldehyde-3-P
G3P
C C C
3C
PGA
phosphoglycerate
3C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
6 ATP
2. G3P
Production
3C
6 ADP
6 NADPH
6 NADP
RuBisCo
 Enzyme which fixes carbon from air
ribulose bisphosphate carboxylase
 the most important enzyme in the world!

 it makes life out of air!

AP Biology
definitely the most abundant enzyme
Photosynthesis summary
 Light reactions
produced ATP
 produced NADPH
 consumed H2O
 produced O2 as byproduct

 Calvin cycle
consumed CO2
 produced G3P (sugar)
 regenerated ADP
 regenerated NADP

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Light Reactions
light  ATP + NADPH + O
2
energy
H 2O +
H2O
sunlight
Energy Building
Reactions
NADPH
ATP
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O2
 produces ATP
 produces NADPH
 releases O2 as a
waste product
Calvin Cycle
CO2 + ATP + NADPH  C6H12O6 + ADP + NADP
CO2
ADP
NADP
Sugar
Building
Reactions
NADPH
ATP
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sugars
 builds sugars
 uses ATP &
NADPH
 recycles ADP
& NADP
 back to make
more ATP &
NADPH
Energy cycle
sun
Photosynthesis
light
CO2 + H2O + energy  C6H12O6 + O2
plants
CO2
H2O
glucose
animals, plants
ATP
C6H12O6 + O2  energy + CO2 + H2O
Cellular Respiration
ATP
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O2
AP Biology
Quick Quiz!
 What molecules are needed for the
Calvin Cycle? 3 CO2, 6 NADPH, & 9 ATP
 What molecule is produced in the
Calvin Cycle? glucose
 What enzyme fixes carbon from CO2
into a useable form? RuBisCo
 Where does the Calvin Cycle take
place? Stroma of chloroplasts
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