photosynthesis
Post on 01-Jan-2016
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Chemosynthesis uses energy released from chemical reactions to produce food for organisms.
Organisms that carry out
chemosynthesis are microbes (bacteria) that live far from the Sun, such as deep on the ocean floor.
Photosynthesis!!!! Which organisms carry out
photosynthesis?
Autotrophs such as plants, some protists and some bacteria
Chloroplast containing chlorophyll
Chloroplasts are found in cells of leaves.
Stoma (Stomata) - small pores on the underside of leaves where gas exchange occurs
Chloroplast structureDisks that contain contain the pigmentChlorophyll are called Thylakoids.
A stack of thylakoids is a GRANUM
The liquid portion of a chloroplast is the STROMA
GRANUM
OVERVIEW OF PHOTOSYNTHESIS
PLANTS TAKE INCO2 AND H2O
PLANTS MAKE GLUCOSE AND OXYGEN
SUNLIGHT PROVIDES THE ENERGY
FOR PHOTOSYNTHESIS
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 steps:
Light Dependent reactions Light Independent reactions (aka
Calvin cycle)
Light Dependent Reaction
Light Independent Reaction
Photosynthesis Light Dependent reaction:
Occurs in the granaMust have light
light
Light Reaction Light Independent Reaction
LIGHT REACTION Light Independent Reaction
thylakoid(chlorophyll)
Step 1: Light Dependent Reactions
H2O O2
O2
O2
O2
O2
H H
How doesthe O2 leavethe leaf?
ENERGY
light energy reacts with the chlorophyll
water is split by the light energy
H is kept for the light independent reaction
O2 is released
O
H2
What happens to the H+?
NADP+ picks up the H+ ions (becoming NADPH) and moves them to the stroma for the light independent reaction (Calvin cycle).
NADPH is a high energy electron carrying molecule.
Light Dependent
Occurs in the thylakoid (grana) Water is absorbed through
roots. Sunlight enters the chloroplast,
causing H2O molecules to split. O2 leaves as a waste product
through the stomata.
NADP+ picks up the H+ ions (becoming NADPH) and moves them to the stroma for the light dependent reaction (Calvin cycle)
ATP( ENERGY) helps to fuel the light independent reaction, or the Calvin Cycle.
Photosynthesis Light Independent reactions (aka
Calvin cycle):Occurs in the stroma
Occurs in the light and dark
Light Reaction Light Independent Reaction
Light Reaction LIGHT INDEPENDENT REACTION
stroma(liquid)
Step 2: Light Independent Reactions
AKA: CALVIN CYCLE
CO2
CO2
CO2
CO2
HC6H12O6
How does CO2
enter the plant?
H from the water split in the light reaction is present
CO2 enters the chloroplastthe reactants H and CO2 combine
HH + CO2
glucose is the product
Other carbohydrates besides glucose may be made in photosynthesis
Light Independent Overview
Carbon dioxide from the atmosphere enters the stoma
H+ breaks off from NADPH NADP+ returns to the Light
Dependent Reaction
Carbon dioxide becomes “fixed” with the H+ producing the glucose molecule C6H12O6.
ATP helps to fuel the light independent reaction. ATP becomes ADP and returns to the light dependent reaction.
Photosynthesis Review Light reactions: H2O split into H2 + O
Light independent reactions: H + CO2 = C6H12O6
H2O Light Reaction Light Independent Reaction
CO 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)
H2OLight Dependent Reaction
Light Independent Reaction
CO 2
C6H12O6
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.
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