In the light reactions, one molecule of the pigment chlorophyll absorbs one photon and loses one electron. This electron is passed to a modified form of chlorophyll called pheophytin, which passes the electron to a quinonemolecule, allowing the start of a flow of electrons down an electron transport chain that leads to the ultimate reduction of NADP to NADPH. In addition, this creates a proton gradient across the chloroplast membrane; its dissipation is used by ATP synthase for the concomitant synthesis of ATP. The chlorophyll molecule regains the lost electron from a water molecule through a process called photolysis, which releases a dioxygen (O2) molecule. The overall equation for the light-dependent reactions under the conditions of non-cyclic electron flow in green plants is:
All of the sugar produced in the photosynthetic cells of plants and other organisms is derived from the initial chemical combining of carbon dioxide and water with sunlight.
So by level of light you probably mean lightintensity which is something that can be measured.Light intensity is usually defined as theenergy hitting an area over some time period.So in the case of a plant, a higher lightintensity means more packets of light called“photons” are hitting the leaves. As you rise fromlow light intensity to higher light intensity, therate of photosynthesis will increase because thereis more light available to drive the reactions ofphotosynthesis. However, once the light intensitygets high enough, the rate won’t increase anymorebecause there will other factors that are limitingthe rate of photosynthesis. A limiting factorcould be the amount of chlorophyll molecules thatare absorbing the light. At a very high intensityof light, the rate of photosynthesis would dropquickly as the light starts to damage the plant.
With too little light, photosynthesis cannotoccur either and the plant suffers without theproduction of sugars. There are many complicatinginteractions between plants and light. I hope thatyou continue to investigate this as the story getsmore interesting and exciting the deeper you go.
Photosynthesis is the process where plants make their own food from sunlight. Most plants are able to make food directly from light energy, for example the Sun, instead of eating other organisms or relying on nutrients. Photosynthesis can happen in plants because they have chlorophyll. Chlorophyll is the pigment that makes plants green. Chlorophyll captures the Sunâs energy and uses it to make sugars out of carbon dioxide from the air and water. The sugars fuel a plant's roots, stems, and leaves so the plant can grow. After plants use the Sun's light to make their food, plants release oxygen into the air. This oxygen is very helpful because humans and animals need it to breathe. Make sure you thank plants for the oxygen you use everyday!
In plants and algae, photosynthesis takes place in organelles called chloroplasts. A typical plant cell contains about 10 to 100 chloroplasts. The chloroplast is enclosed by a membrane. This membrane is composed of a phospholipid inner membrane, a phospholipid outer membrane, and an intermembrane space between them. Within the membrane is an aqueous fluid called the stroma. The stroma contains stacks (grana) of thylakoids, which are the site of photosynthesis. The thylakoids are flattened disks, bounded by a membrane with a lumen or thylakoid space within it. The site of photosynthesis is the thylakoid membrane, which contains integral and peripheral membrane protein complexes, including the pigments that absorb light energy, which form the photosystems.
In plants, algae and cyanobacteria, sugars are produced by a subsequent sequence of light-independent reactions called the Calvin cycle, but some bacteria use different mechanisms, such as the reverse Krebs cycle. In the Calvin cycle, atmospheric carbon dioxide is incorporated into already existing organic carbon compounds, such as ribulose bisphosphate (RuBP). Using the ATP and NADPH produced by the light-dependent reactions, the resulting compounds are then reduced and removed to form further carbohydrates such as glucose.
Although photosynthesis is performed differently by different species, the process always begins when energy from light is absorbed by proteins called reaction centres that contain green chlorophyll pigments. In plants, these proteins are held inside organelles called chloroplasts, which are most abundant in leaf cells, while in bacteria they are embedded in the plasma membrane. In these light-dependent reactions, some energy is used to stripelectrons from suitable substances such as water, producing oxygen gas.
Light energy is absorbed by the green chemical chlorophyll. This energy allows the production of glucose by the reaction between carbon dioxide and water. Oxygen is also produced as a waste product.
A second idea common to science and religion is energy. In both cases energy is the prime mover or First Cause of the Universe, physical or spiritual. No prior explanation for the existence of energy can be given in either science or religion; energy cannot be derived from any preexisting or more primitive source. What we can say about the essence of energy is very limited: 1) it is the principle of action, expressed through change, especially entropy; 2) it is the cause of all reality, taking various forms (including information and life); 3) it is absolutely conserved; 4) its source is unknown. Are these terms religious or scientific? The case could be made for either view.
Is energy created in the "Big Bang"? It is thought that the negative energy/entropy of gravitation exactly balances the positive energy of the "Creation Event", so that the Cosmos originates from a state of no net energy (and, due to an equal measure of antimatter, from a state of no net charge). There is a familiar resonance here with the mythological division of the cosmos into light vs dark domains, the Heavens ruled by the God of light, the Earth/darkness/matter ruled by an evil god (the "devil").
Photosynthesis is a process used by plants in which energy from sunlight is used to convert carbon dioxide and water into molecules needed for growth. These molecules include sugars, enzymes and chlorophyll.
Karma and Information
A third link between science and religion is the notion of causality or "karma", and the sequential linkage of cause and effect. The notion extends to the proscription of action-at-a-distance; in physics there must be an intervening field of particles, virtual if necessary, to transmit a force - causality requires time, connection, and information. In the case of light, gravitation, and inertia, spacetime itself supplies the connecting field. The connectivity of all life is demonstrated by the DNA "field"; the "particle" field extends this principle to all matter; spacetime and gravitation are examples of metric fields which bind together all forms of energy at the cosmic scale. Matter-antimatter annihilation reactions demonstrate the universal character of electromagnetic energy. In the temporal domain, at astronomical scale, our "yesterday" is part of some other observer's "today", and vice versa. Today is real only because yesterday remains real: historic spacetime is the conservation domain of matter's causal information field, network, or "matrix". Light is connected by space, matter is connected by history; gravity connects all, The connectivity of the Cosmos is complete in a physical sense. But this very connectivity is the essence of spirit and causality, in both its religious and scientific sense. ("Chaos" and quantum theory do not describe a lack of connection, but only the lack of certain kinds of predictability concerning these phenomena.) Information is a necessary adjunct of Causality, and in its most primordial and biologically significant form, it corresponds to the charges of matter. Information in the form of charge (including gravitational charge) controls the fate of the Cosmos, providing on the one hand a roadmap for the lawful return of the material Cosmos to its symmetric origins in light, and on the other, a pathway to life, consciousness, and the self-awareness of the Universe.