Photosynthesis

• The sun is the main source of energy for the earth.
• Autotrophs make their own food and most are green plants.
• Autotrophs make food by carrying out photosynthesis.
• Plants use photosynthesis to make food.
• Animals get their food from plants, so get their food from photosynthesis.
• Photosynthesis produces Oxygen, which most living things need to respire and live.
• Photosynthesis was responsible for forming some fossil fuels such as oil, peat and coal.
• In photosynthesis, Protons are stored in a storage pool for the chloroplast to use later on.
• In photosynthesis, Electrons are passed to chlorophyll.
• In photosynthesis, Oxygen may pass from the chloroplast, into the cytoplasm and out of the leaf or the Oxygen may be used inside the leaf for respiration.
• Light is trapped by chlorophyll and provides the energy for photosynthesis.
• Water is split in photosynthesis, with the sunlight energy used to split water in half (photolysis).
• The products from splitting water in photosynthesis are Protons passed to a storage pool for later use, Electrons passed to chlorophyll, and Oxygen can be used in respiration or released out of the leaf.
• Glucose is formed when the high-energy electrons, protons from the storage pool and Carbon Dioxide from the air are combined, this is called the Calvin cycle.
• Plants have two sources of Carbon Dioxide, one external and one internal.
• The H+ from the storage pool is now used and stuck to the NADP to form NADPH.
• As the highenergy electrons move, they lose energy and this energy forms ATP.
• The Light Stage of photosynthesis happens in the Chloroplast and involves electrons (electricity) so reactions happen very quickly.
• In the Light Stage of photosynthesis, light is absorbed, light energy is transferred to electrons, and electrons move from the electron acceptor to the chlorophyll that has the electron acceptor attached.
• Water is absorbed from the soil by the roots by osmosis, passes up the xylem in stem and into the leaves.
• Higher Level Photosynthesis is split into two main stages, the Light and the Dark Stage.
• In pathway 1, the highenergy electrons move from the electron acceptor to other electron acceptors, travel in a circle and back to where they started.
• Both ATP and NADPH carry energy into the Dark Stage to make Glucose.
• At the end of pathway 2, ATP and NADPH have been made.
• Eventually the two electrons join to NADP+ and make NADP.
• In pathway 2, two highenergy electrons move from the electron acceptor to other electron acceptors, they don't travel in a circle, and as they move they lose energy and this energy forms ATP.
• NADPH, ATP and Oxygen are the end products of the Light Stage of photosynthesis.
• ATP will provide energy for reactions in the Dark Stage.
• Most of the carbon dioxide used by plants comes from the outside air, this is the external source of Carbon Dioxide.
• Some carbon dioxide used in photosynthesis comes from respiration, this is the internal source of Carbon Dioxide.
• Oxygen is made from the split water and released from the leaf or recycled in Respiration.
• Carbon Dioxide enters the leaf through the pores (stomata) and the Calvin Cycle uses the CO2 and mixes it with the H from the NADPH, making C6H12O6 (Glucose).
• A higher photosynthesis rate means more O2 bubbles per minute.
• In the Dark Stage of photosynthesis, water is split into H2O and Oxygen is released or used in Respiration.
• The Dark Stage of photosynthesis happens in the Chloroplast and involves enzymes, so reactions happen slowly.
• The rate of photosynthesis can be measured by the number of bubbles produced per minute.
• The glucose is then stored as starch for later use in Respiration.
• In the Light Stage of photosynthesis, light is absorbed by chlorophyll and sunlight energy is converted into high-energy electrons that move in two pathways.
• In the Light Stage of photosynthesis, water is split into H+, oxygen, electrons. Oxygen is released or used in Respiration.
• NADPH provides energy and the H12 for Glucose.