Photosynthesis is probably the most important biological process on Earth. Converting light into chemical energy stored as sugar, photosynthetic organisms can use the Sun's energy to power the chemical processes that keep them alive, as so all the other organisms that depend on them.
Photosynthesis is a two step process. The first step is formed by the light reactions. On this step, light is gathered and used to produce oxygen, hydrogen ions and a bit of temporary chemical energy in the form of ATP molecules.
The second step, formed by the so called dark reactions, takes the hydrogen, the ATP and carbon dioxide from the atmosphere and produce sugar precursors in a cycle of chemical reactions called the Calvin Cycle.
The second step, formed by the so called dark reactions, takes the hydrogen, the ATP and carbon dioxide from the atmosphere and produce sugar precursors in a cycle of chemical reactions called the Calvin Cycle.
In plant cells, photosyntheses happens inside special organelles called chloroplats. In the interior of the chloroplast, where there are systems of stacked flat membranous sacks called Thylakoids. On the surface of the thylakoids is located the biomolecular machinery responsable for gathering light.
Everything starts when photons of light hit the membrane of thylakoids , where the photosystems are located. The photosystems are molecular complexes that contain chlorophyll, which is responsable for absorbing the photons.
When clorophyll molecules absorbs the light, it produces energetic electrons. These electrons are collected and moved across an electron transport chain, a series of molecular complexes that extracts their energy to pump hydrogen ions across the membranes of the thylakoids creating an electrochemical gradient (chemiosmosis) that is harnessed by proton turbines (ATP synthase enzymes) to produce ATP, a molecule uses to store the energy for the next dark reactions.
In the process, the chlorophyl molecules will also break an water molecule, producing oxygen and hydrogen ions. The electrons will be pass through a second photosystem where they are reenergized by another photon of light, be used to make more ATP before finally be recombined with hydrogen ions to produce NADPH molecules, which will participate in the next set of reactions together with ATP.
In the process, the chlorophyl molecules will also break an water molecule, producing oxygen and hydrogen ions. The electrons will be pass through a second photosystem where they are reenergized by another photon of light, be used to make more ATP before finally be recombined with hydrogen ions to produce NADPH molecules, which will participate in the next set of reactions together with ATP.
In the dark reactions, CO2 is captured from the atmopshere, reacted with NADPH, using the energy stored in the ATP to produce sugar through the Calvin cycle.
The cycle starts with the reaction of a carbon dioxide molecule with a ribulose-1,5-bisphosphate (RuBP) molecule, forming two molecules of 3-phosphoglycerate (3-PGA). These 3-PGA molecules are reacted with ATP to produce 1-3-biphosphogycerate molecules, which are further reacted with NADPH to produce Gyceraldehyde 3-phosphate (G3P).
Through one turn of the cycle's reactions, 3 carbon dioxide molecules are reacted, plus 9 ATP molecules and 6 NADPH molecules to produce 6 G3P. Five are renerated back into 3 RuBP molecules so the cycle can start again, while one is set appart.
The cycle starts with the reaction of a carbon dioxide molecule with a ribulose-1,5-bisphosphate (RuBP) molecule, forming two molecules of 3-phosphoglycerate (3-PGA). These 3-PGA molecules are reacted with ATP to produce 1-3-biphosphogycerate molecules, which are further reacted with NADPH to produce Gyceraldehyde 3-phosphate (G3P).
Through one turn of the cycle's reactions, 3 carbon dioxide molecules are reacted, plus 9 ATP molecules and 6 NADPH molecules to produce 6 G3P. Five are renerated back into 3 RuBP molecules so the cycle can start again, while one is set appart.
The G3P molecules produced are used as precursors for the production of any sugar molecule used by the plant's cells.
Through a series of further reactions catalysed by their respective enzymes it's possible to get glucose and frutose from G3P. These sugas can further be combined to produce sucrose. Glucose can be also be polymerized to make starch and cellulose.
Through a series of further reactions catalysed by their respective enzymes it's possible to get glucose and frutose from G3P. These sugas can further be combined to produce sucrose. Glucose can be also be polymerized to make starch and cellulose.
In Nanotechnology there is the concept of Mechanically Interlocked Molecular Architectures. These are molecules that are connected together because of their shape (also called a "mechanical bond") instead of chemical bonds or intermolecular interactions.
Because of the presence of mechanically interlocked molecules reduce the degrees of freedom of movement of the molecules involved, some chemical reactions are slown down.
One application of that would be the creation of more durable dyes that don't degrade as fast.
One application of that would be the creation of more durable dyes that don't degrade as fast.
Other possibilities include the creation of molecular machines, with moveable parts that are controled by external stimuli (electric, chemical, light, heat and etc) to perform specific tasks. Or logic circuits on molecular computers.