photosynthesis song! 6.11 the mechanism of photosynthesis text book page 133
TRANSCRIPT
Photosynthesis Song!
6.11 The Mechanism of Photosynthesis
Text Book page 133
Watch chloroplast in 3D!
Watch chloroplast in 2D!
Structure of a chloroplastStarch granuleStorage of insoluble products of photosynthesis
Chloroplast envelopePermeable to glucose, ions, O2 and CO2
Thylakoid
Granum•Stacks of thylakoid membrane•Important in ATP synthesis•Site of light reaction
Stroma•Is a gel-like matrix•Site of dark reaction
Lipid droplet
Light Reaction In Granum
Photolysis of water
water
24OH-
24e- 24OH
6O212H2O
chlorophyll24e-24H
24H+
24H2O
Sunlight
Dark reaction in stroma
1. Chlorophyll absorbs sunlight and produces energy. Energy activates the water molecules to dissociate into H+, OH- and e-
Neutral hydroxyl groups combine together to form water and O2
2. Chlorophyll becomes excited and releases e-
3. Each H+ receives an e- from the chlorophyll and is neutralised to form a neutral hydrogen atom (H)
Quick check!
Dark Reaction in Stroma
6CO2
6(CH2O) +
C6H12O6
Starch
6H2O
Released to atmosphere
(Glucose)
4. Hydrogen atoms (H) are used in dark reaction to fix CO2 which is catalysed by photosynthetic enzymes.
6 units of CH2O will combine to form a molecule of glucose.
condensation
Protein Lipids
Quick check!
SPM Clone Question!
Light reaction
Light reaction
R
Q
Light energy
glucose water+
What do P, Q and R represent?
Answer:P = Hydrogen atomQ = oxygenR = carbon dioxide
P
Water + Carbon dioxide Glucose + Oxygen
6H2O 6CO2
Light
Chlorophyll C6H12O6 6O2
SPM Clone Question!
Carbon dioxide + X Glucose Y+
What are X and Y?
Answer: X = water , Y = oxygen
SCHEMATIC DIAGRAM OF PHOTOSYNTHESIS
Photosynthesis
Light Reaction Dark Reaction
Chlorophyll sunlight
Water (H2O)
Hydrogen ions (H+)
CO2Hydrogen (H)
Hydroxide ions (OH-)
Hydroxyl groups (OH)
O2 H2O
Basic glucose units (CH2O)Water (H2O)
Glucose (C6H12O6)
Air / Atmosphere Proteins Lipids Carbohydrates
requires
absorb
Breaks up
combines
forms
Absorb e-
split
Release e-
goes
Comparison between light and dark reactions
Similarities
Differences
As to conclude, watch this!
As to conclude, do this!
1. Define photosynthesis. (2 m)
2. Photosynthesis occurs as a string of chemical reactions. Explain how photosynthesis happens in green plants. (8 m)
Thank you for your attention!
Hehehehe….