Part 1
• Carbohydrates
Energy Release
energy is
• When bonds are broken, __________
released for use by the cell
ATP
Glucose
Fructose
Sucrose: A disaccharide
Monosaccharides
Energy Storage
• When bonds are made, energy (E) is
stored
Glucose: A Monosaccharide
Fructose: A Monosaccharide
Sucrose: A dissaccharide
Carbohydrates
1. Carbohydrates are:
– an important energy (E) source
– Cellular structures
2. Carbon, Hydrogen and Oxygen in a
ratio of 1:2:1
3. General Formula (CH
CH2O)n
O
Carbon
Water = hydrate
Types of Carbohydrates
Monosaccharides (simple sugars)
– Contain 3-7 Carbons each
• Examples: Glucose
Glucose, Galactose, Fructose
Types of Carbohydrates, cont…
Disaccharides (two sugars)
• Examples: Sucrose
Sucrose, Maltose, Lactose
– Maltose = Glucose + Glucose
– Lactose = Glucose + Galactose
Glucose
Fructose
Types of Carbohydrates, cont…
Polysaccharides (many sugars)
• Examples: Starch
Starch, Glycogen, Cellulose
Chloroplast
Starch
Liver Cell
Cellulose
Plant Cells
Glycogen
Plant Cells
Check
for
Understanding…
I’m a carbohydrate polymer
made of 4 monomers. What
are my monomers called?
Monosaccharides, of
course!
Part 2
Bond Energy and Energy Storing
Compounds
ATP, NADPH, FADH2, NADH
How is energy released?
• When bonds are made by dehydration
synthesis, energy is stored within the
bonds of the compound.
ATP
OH
HO
Glucose
Fructose
Sucrose: A disaccharide
Monosaccharides
How is energy released?
• When bonds are broken by hydrolysis,
energy
__________
is released from the bonds
ATP
Glucose
Fructose
Sucrose: A disaccharide
Monosaccharides
What are some examples of
common energy storing
compounds?
1. ATP (Most important usable energy for
the cell.)
2. NADPH
3. FADH2
4. NADH
How is ATP made?
• ATP is made from the precursor AMP
(Adenosine Mono-phosphate)
• If a phophate and energy is added to
AMP, ADP is created.
• Furthermore, if another phosphate is
added to ADP, ATP is created.
How ATP is Made
• AMP
A
P
• ADP
A
P
P
• ATP
A
P
P
P
Equation for ATP synthesis
• ADP + P + energy  ATP
How are NADPH, FADH2, and
NADH made?
•
•
•
•
NADP+ + H+ + electrons  NADPH
FAD+ + 2H+ + electrons  FADH2
NAD+ + H+ + electrons  NADH
Notice that high energy electrons and
hydrogen ions (H+) are needed to create
NADPH, FADH2 and NADH.
Part 3
Introduction to Photosynthesis
1. Mesophyll
1. Mesophyll
A layer of cells that
contain chloroplasts &
are responsible for most
of the plant’s
photosynthesis
Page 2
Page 2
O2
2. Stomata
Openings in plant leaves that
allow for gas exchange to occur
Carbon Dioxide (CO2) passes in
and Oxygen (O2) passes out.
CO2
Mesophyll Cell
3. Chloroplast
The site of Photosynthesis
Double-membrane
bound organelle
4. Outer membrane
5. Inner membrane
Page 2
8. Grana
7. Thylakoid
Chlorophyll
resides in these
membranes
6. Stroma
8. Grana
Page 2
Page 4
Pathway of Photosynthesis
On your own, balance this equation:
6 CO2 + 6 H2O + (Light)  1 C6H12O6 + 6 O2
Reactants must equal Products
Carbon 6
Carbon 6
Hydrogen 12
Hydrogen 12
Oxygen 18
Oxygen 18
Label the image in your notes, and fill in the notes provided
Thylakoid
Page 4
Page 4
Page 4
Photosynthesis: The Light Reaction
• Chloroplasts are
chemical factories
powered by the sun.
• Their thylakoids
transform light energy
into the energy of
NADPH and ATP .
Page 5
The Nature of Light
Page 5
The Nature of Light
• The particles of
light are called
photons .
Page 5
Page 5
Why are leaves green?
Substances that absorb light are called pigments
Carotenoids
Chlorophyll a
Chlorophyll b
Chlorophyll absorbs red
and
blue
light, reflecting green
Fluorescence of Chlorophyll
High energy state
e-
Energy of electron
Heat
Photon
Fluorescence
Chlorophyll
molecule
Ground state
Photosystems: Harvest Light
Photon
Electron Transfer
(high energy
state)
Transfer of Energy
Primary Electron Acceptor
Reaction Center
Chlorophyll
Antenna pigment
molecules
Light Reaction
Primary
Acceptor
Energy of Electrons
Primary
Acceptor
5)
2e-
2eETC
NADP+ + H+
NADPH making
enzyme
2) Spliiting of
water releases
O2 gas and refills
2e- to the
chlorophill
pigment
H2O
2H
2e+ +
O2
Electron
Transport
Chain (ETC)
NADPH
3) Electrons “fall” in energy,
moving through a protein
complex called the ETC, and
ATP is created from this energy
4) photons
1) photons
2 e-
ATP
Photosystem II
Photosystem I
Mechanical analogy for the
light reactions
1. Photon excites an electron
in Photosystem II
2. ATP is produced during this
stage (ETC)
3. The electron moves on to
Photosystem I
4. An electron is excited
by another photon
5. NADPH is produced
ATP Synthetase
• An enzyme embedded in
the thylakoid membrane
• Creates
ATP from
the
electron’s
energy in
the ETC
Thylakoid
membrane
Protein
Complex
Enzyme
Summary of the Light Reaction
+
+
NADPH
++ +
+ 2e4e+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
ATP
Dark Reaction:
An Overview
• The General Formula for Photosynthesis is:
6CO2 + 6H2O + (Light )  C6H12O6 +6O2
• Which of these reactants has not been accounted
for so far?
ATP
NADPH
ATP & NADPH energy
are used to convert
CO2 into glucose
CO2
Sugar!
This is done in a
three-phase cycle…
RuBP
PGA
STEP 1: Carbon fixation
5-Carbon Sugar (RuBP)
+ CO2
two 3-Carbon Compounds (PGA)
ATP and NADPH energy is used
This energy rearranges atoms of
PGA
PGA changes into PGAL, a
different 3-carbon sugar
PGAL
Phase 2: Makes
PGAL, a 3Carbon sugar
Phase 2: Makes
PGAL, a 3Carbon sugar
PGAL
Let’s play the photosynthesis
magnet board race!