Understandings:
Light dependent:
• Light-dependent reactions take place in the intermembrane space of the thylakoids.
• Reduced NADP and ATP are produced in the light-dependent reactions.
• Absorption of light by photosystems generates excited electrons.
• Photolysis of water generates electrons for use in the light-dependent reactions.
• Transfer of excited electrons occurs between carriers in thylakoid membranes.
• Excited electrons from Photosystem II are used to contribute to generate a proton gradient.
• ATP synthase in thylakoid membranes generates ATP using the proton gradient.
• Excited electrons from Photosystem I are used to reduce NADP.
Light dependent:
• Light-dependent reactions take place in the intermembrane space of the thylakoids.
• Reduced NADP and ATP are produced in the light-dependent reactions.
• Absorption of light by photosystems generates excited electrons.
• Photolysis of water generates electrons for use in the light-dependent reactions.
• Transfer of excited electrons occurs between carriers in thylakoid membranes.
• Excited electrons from Photosystem II are used to contribute to generate a proton gradient.
• ATP synthase in thylakoid membranes generates ATP using the proton gradient.
• Excited electrons from Photosystem I are used to reduce NADP.
|
What products are formed from the light dependent reactions?
ATP H+ H2O NADPH |
|
Phosphorylation stage - electron transport chain in the thylakoid membrane to create ATP
|
|
Light Independent / Calvin Cycle
• Light-independent reactions take place in the stroma.
• In the light-independent reactions a carboxylase catalyses the carboxylation of ribulose bisphosphate.
• Glycerate 3-phosphate is reduced to triose phosphate using reduced NADP and ATP.
• Triose phosphate is used to regenerate RuBP and produce carbohydrates.
• Ribulose bisphosphate is reformed using ATP.
• Light-independent reactions take place in the stroma.
• In the light-independent reactions a carboxylase catalyses the carboxylation of ribulose bisphosphate.
• Glycerate 3-phosphate is reduced to triose phosphate using reduced NADP and ATP.
• Triose phosphate is used to regenerate RuBP and produce carbohydrates.
• Ribulose bisphosphate is reformed using ATP.
What must be present for the light independent reactions to occur? CO2; products from light reaction
What products are formed? C6H12O6
What products are formed? C6H12O6
|
|
The structure of the chloroplast is adapted to its function in photosynthesis.
Skill: Annotation of a diagram to indicate the adaptations of a chloroplast to its function.
Skill: Annotation of a diagram to indicate the adaptations of a chloroplast to its function.
|
|
|
Skill: Design of experiments to investigate the effect of limiting factors on photosynthesis.
Water free of dissolved carbon dioxide for photosynthesis experiments can be produced by boiling and cooling water.
Aim 6: Hill´s method demonstrating electron transfer in chloroplasts by observing DCPIP reduction, immobilization of a culture of an alga such as Scenedesmus in alginate beads and measurement of the rate of photosynthesis by monitoring their effect on hydrogencarbonate indicator are all possible experiments.
Water free of dissolved carbon dioxide for photosynthesis experiments can be produced by boiling and cooling water.
Aim 6: Hill´s method demonstrating electron transfer in chloroplasts by observing DCPIP reduction, immobilization of a culture of an alga such as Scenedesmus in alginate beads and measurement of the rate of photosynthesis by monitoring their effect on hydrogencarbonate indicator are all possible experiments.
|
The Global Artificial Photosynthesis (GAP) project aims to create an artificial “leaf” within the next decade. An electronic version of the leaf that creates oxygen and hydrogen from water and sunlight has already been invented and will be developed for use in the next decade.
|
Emmett Chappelle - 1925-2019 Chappelle made a major discovery that has largely contributed to the knowledge of bacteria, cyanobacteria, and other single-celled organisms around the world. He discovered that even single-celled organisms such as algae, are photosynthetic, meaning they are able to convert carbon dioxide to oxygen. Since humans rely on cellular respiration, the conversion of oxygen to carbon dioxide, and algae relies on photosynthesis, the conversion of carbon dioxide to oxygen, astronauts were able to survive in space with a constant renewal of oxygen. This knowledge was not only beneficial to astronauts because it allowed scientists to develop a method for creating clean oxygen for astronauts in space, but it also provided them with a safe food source that is capable of reproducing in space. |
Theory of knowledge:
The lollipop experiment used to work out the biochemical details of the Calvin cycle shows considerable creativity. To what extent is the creation of an elegant protocol similar to the creation of a work of art?
The lollipop experiment used to work out the biochemical details of the Calvin cycle shows considerable creativity. To what extent is the creation of an elegant protocol similar to the creation of a work of art?
