Calvin Cycle and Hatch-Slack Cycle | Photosynthesis
Oxygenic photosynthesis uses two systems for capturing photons. The first one (called ) uses . The second one (called because it was discovered before Photosystem II) uses captured photon energy to add an electron to captured carbon dioxide to help transform it into a sugar. That “” is accomplished by the , and an enzyme called Rubisco, , catalyzes that fixation. Below is a diagram of the Calvin cycle. (Source: Wikimedia Commons)
Noncyclic Cycles in Photosynthesis ..
The respiration and photosynthesis cycles in complex organisms have been the focus of a great deal of scientific effort, and cyclic diagrams (, ) can provide helpful portrayals of how cycles work. Photosynthesis has several cycles in it, and Nobel Prizes were awarded to the scientists who helped describe the cycles. Chlorophyll molecules , with magnesium in their porphyrin cages, and long tails. Below is a diagram of a chlorophyll molecule. (Source: Wikimedia Commons)
As oxygenic photosynthesis spread through the oceans, everything that could be oxidized by oxygen was, during what is called the (“GOE”), although there may have been multiple dramatic events. The event began as long as three bya and is . The ancient carbon cycle included volcanoes spewing a number of gases into the atmosphere, including hydrogen sulfide, sulfur dioxide, and hydrogen, but carbon dioxide was particularly important. When the continents began forming, carbon dioxide was removed from the atmosphere via water capturing it, , the carbon became combined into calcium carbonate, and plate tectonics subducted the calcium carbonate in the ocean sediments into the crust, which was again released as carbon dioxide in volcanoes.
This does not create a cycle, hence the name non-cyclic
Cyclic electron flow helps move the electrons throughout photosystem 1 for cyclic photophosphorylation.
Noncyclic electron flow moves electrons through both Photosystem 1 and 2.
What are the Cyclic and Non-Cyclic Pathways in Photosynthesis
Photolysis, water splitting, is present.
Oxygen changes during the process.
Takes place in plants.
Uses only Photosystem 1
The reaction center is P700
The electrons travel in a cyclic manner
Photolysis is not present.
Oxygen does not change throughout the process.
Most often used by bacteria.
Steps That Lead to Phosphorylation
Photosynthesis is a two step process that consists of the light and dark reactions.
Photophosphorylation is the process of generating ATP from ADP , by proton motive force generated by the thylakoid membrane.
Photophosphorylation takes place during the light reaction step in photosynthesis.
In light reaction, the addition of phosphate in the presence of light is called photophosphorylation.
Compare and contrast cyclic and non-cyclic ..
Noncyclic Photophosphorylation uses both photosystems 1 and 2.
The electrons transport in a noncyclic manner.
The active reaction center uses P680.
Photosynthesis Non-Cyclic Electron ..
Non Cyclic Electron Flow is the production of ATP by noncyclic electron flow.
Noncyclic electron flow is the route of electron flow that goes through both photosystems.
It produces ATP, NADPH, and oxygen.
The net electron flow is from water to NADP+