“Plants, instead of affecting the air in the same
manner as animal respiration, reverse the effect of
breathing and tend to keep the atmosphere sweet
and wholesome”
-Joseph Priestly
1733-1804
PLANTS!!!!
Photosynthesis
a series of chemical reactions
controlled and carried out by
specific enzymes
Ex-Aldolase
Think back………
Photosynthesis
Photosynthesis
• Leaf anatomy
Start here
Photosynthesis
• Leaf variety
– Why so many?
•
Photosynthesis
Sun-Ultimate
Source of Energy
•
Not all of the light from
the Sun makes it to the
surface of the Earth.
• The little light that does
make it here is enough
for the plants of the world
to survive and go through
the process of
photosynthesis.
Photosynthesis
• Even when light gets to a plant, the plant
doesn't use all of it. It actually uses only
certain colors to make photosynthesis
happen.
• Autotrophy
• Heterotrophy
Photosynthesis
• THE CHLOROPLAST
• Photosynthesis happens in
the chloroplast
• Light energy is harvested
and convert to chemical
energy
Photosynthesis
Photosynthesis
2 sets of reactions:
LIGHT-DEPENTENT REACTION
•
•
•
•
Occurs in the thylacoid membrane
Sunlight split water
Hydrogen is used to produce ATP
Oxygen is given off as waste
LIGHT-INDEPENDENT REACTION
•
•
•
•
Once ATP is formed the rest of the reactions
can take place “in the dark”
Occurs in the Stoma
CO2 is reduced to glucose
A set of cyclic reactions: the Calvin cycle
Photosynthesis
• How DOES the
Chloroplast
harness the suns
energy?
– Absorption
– Colors
Photosynthesis
• Within the chloroplast is chlorophyll that
captures the light from the Sun.
• Chlorophyll is the magic compound that
can grab that sunlight and start the whole
process.
Plants mostly
absorb red
and blue
wavelengths
of light
Photosynthesis
• In order for an organism to use light
energy , it must absorb that energy.
• Plants use pigments to absorb light
energy.
• ****************
• Main photosynthetic pigment
• Accessory pigments
Photosynthesis
Photosynthesis
• For today
– Three excercises…..
Photosynthesis
Exercise 9.1
• Use spectrophotometer to
find the wavelength at which
highest rate of
photosynthesis occurs
•
Spinach pigment extracts
Photosynthesis
• Exercise 9.2
• Isolate the four pigment in spinach
•
Chlorophylls a & b (reflect green)
•
Carotenoids and Xanthophyll (reflect red-orange-yellow)
Photosynthesis
Exercise 9.2
• Analytical method of
separating pigments
• Based on capillary action,
and the fact that different
pigments separate based
on their rates of travel
through the paper
• Hydrophilic or hydrophobic
(affecting solubility)
Photosynthesis
Exercise 9.3 ( demo)
Safety and Clean up
• Acetone – will be recycled
Photosynthesis
• The earth depends on
the ability of
photosynthetic
organisms to convert
the radiant energy of
the sun into ATP,
Oxygen, and other
nutrients
Formal Lab Report
 Results
 Discussion
 Literature
 Unit
Cited
8 - Enzymes
Formal Lab Report
Title - should include exactly what you studied.
5
Introduction- should identify what you studied
and provide relevant background information.
The introduction must end with your hypothesis.
15
Materials and Methods - describe how and when
you did your work, including ALL equipment,
methods of gathering and analyzing data.
10
Results - observations and data with no
interpretations or conclusions. You must include
at least one typed table or graph along with your
daily growth records.
20
Discussion - explain what you think your data
means. Describe patterns and relationships that
emerged.
20
References or Literature cited - references must
be cited using MLA format and you must have at
least one reference.
15
Neatness All aspects of this report must be typed.
15
No handwritten graphs/tables/charts will
be accepted.
Use Ex 9.2
Pigment
chromatography