photosynthesis. what is the ultimate source of all energy? what is your source of energy?
TRANSCRIPT
Photosynthesis
What is the ultimate source of all energy?
What is your source of energy?
EQ: Why do plants absorb multiple wavelengths of light?
energy
energy
Why do we see colors?
The sun sends down little packets of light energy called:
PHOTONS
Why do we see colors?
Photons group together in waves The waves have different lengths Each “wavelength” presents
itself as a colorPhotons
Wavelengths
Why do we see colors? Pigments (chlorophyll) absorb
wavelengths of light. The wavelengths not absorbed are reflected as color that we see.
red
yellow
blue
green
orange
STAGE 1Light Absorption
Chlorophyll in Thylakoids
ROY G BIVWeakestStrongest
Why do we see colors? What color is chlorophyll?
The plant pigment chlorophyll reflects light in
these wavelengths.
The plant pigment chlorophyll absorbs the red and blue colors of light and uses the energy to power
photosynthesis.
Uses Most? Uses Least?
= Blue and Red
= Green and Yellow
Pigments =Chlorophyll a and b
EQ: How do photosynthetic organisms produce food?
PHOTOSYNTHESIS: Structures and
Process
Chemical Equation for Photosynthesis
Sunlight + Carbon Dioxide + Water Glucose (sugar) + Oxygen
6CO2 + 6H2O C6H12O6 + 6O2
Light
Light Energy
CO2 + H2OChloroplast
Sugars + O2
Chloroplast Structure Photosynthesis occurs in the chloroplast. Chlorophyll is the pigment (filling) found
inside chloroplasts.A disks called a THYLAKOID contains the pigment CHLOROPHYLL.
The liquid portion of a chloroplast is the STROMA
A stack of thylakoids is called a GRANA.
How do Plants Make Food?
overview of photosynthesis
STEPS OF PHOTOSYNTHESIS
1. PLANTS TAKE INCO2 AND H2O
4. PLANTS MAKE GLUCOSE AND RELEASE OXYGEN
2. SUNLIGHT PROVIDES THE ENERGY
FOR PHOTOSYNTHESIS
water
carbon
dioxide
light
carbohydrates
oxygen
3. SUNLIGHT CAPTURED BY CHLOROPHYLL
Photosynthesis What is photosynthesis? Photosynthesis is the process
by which:
water
carbon dioxide
oxygen
glucose
TAKE IN AND USING MAKE
PLANTS(producers)
light
chlorophyll
Photosynthesis 2 Phases:
Light cycle (light-dependent)Calvin cycle (light-independent)
Light Reaction Dark Reaction
Who was Calvin anyway?
A member of the faculty at UC Berkeley since 1937, Melvin Calvin received the 1961 Nobel prize in chemistry for identifying the path of carbon in photosynthesis.
The cycle of reactions in the dark phase of photosynthesis was named after him for his work in identifying the processes taking place.
Photosynthesis Light cycle:
Occurs in the grana (where chlorophyll is)
Must have light
light
Light Reaction Dark ReactionLIGHT REACTION Dark Reaction
grana(chlorophyll)
Part 1: Light Cycle (4 steps)
H2O O2
O2
O2
O2
O2
H H
How doesthe O2 leavethe leaf?
ENERGY
1. light energy is absorbed with the chlorophyll
2. water is split into H and O2 by the light energy
3. H is kept for the dark reaction
4. O2 is released
O
H2
Photosynthesis Calvin cycle
Occurs in the stromaOccurs in the light and dark
Light Reaction Dark ReactionLight Reaction DARK REACTION
stroma(liquid)
Part 2: Calvin Cycle
CO2
CO2
CO2
CO2
HC6H12O6
How does CO2
enter the plant?
1. H (hydrogen) from the water split in the light reaction is present
2. CO2 enters the chloroplast
3. The reactants H and CO2 combine
HH + CO2
4. Glucose is produced
Photosynthesis Review
Light cycle: H2O H2 + O
Calvin cycle: H + CO2 C6H12O6
H2O Light Reaction Dark ReactionC
O 2
C6H12O6
O 2
chlorophyll
Photosynthesis Formula How would this be written as a
chemical equation? What goes in? (the reactants)
What comes out? (the products)
H2O Light Reaction Dark ReactionC
O 2C6H12O6
O 2
chlorophyll
H2O CO2 C6H12O6 O2
Photosynthesis Formula What’s wrong with this equation? The number of atoms is not equal on
both sides of the equation.
Balance the equation so that the number of atoms of each element is equal on both sides.
H2O CO2 C6H12O6 O2
one carbon atom reactant
6 carbon atoms product
6 6 6(1)
Now balance it as if TWO glucose molecules were being produced.
Photosynthesis Review What goes in? (the reactants) What comes out? (the products)
H2O Light Reaction Dark Reaction
CO 2
C6H12O6
O 2
chlorophyll
6CO2 + 6H2O 6O2 + C6H12O6
light
chlorophyll
What are Carbohydrates?
Organic Compounds that store light energy from the sun as chemical energy that can be used by living things
Carbohydrates are made by plants during photosynthesis.
Light-Dependent Reactions
NADPH
ATP
Figure 8-7 Photosynthesis: An Overview
Go to Section:
LightWater
O2
Stage 1 and 2“Light Dependent”
Light + Water ATP + NADPH + Oxygen
Light Energy Converted to Chemical Energy
CalvinCycle
NADPH
ATP
ADP + PNADP+
Figure 8-7 Photosynthesis: An Overview
Go to Section:
CO2
Sugar!!!
Stage 3“Light Independent”
ATP + NADPH + CO2 Sugar + NADP+ + (ADP +P)
Light-Dependent Reactions
CalvinCycle
NADPH
ATP
ADP + PNADP+
Figure 8-7 Photosynthesis: An Overview
Go to Section:
LightWater
O2
CO2
Sugar!!!
PHOTO vs. RESPIRATION
End products of Photosynthesis
Beginning products of Respiration
What have in common?
“Circle of Life”