For older stars which are collapsing at the center, the temperature can exceed one hundred million Kelvin and initiate the helium fusion process called the triple-alpha process. For brief periods near the end of the luminous lifetime of stars, heavier elements up to iron may fuse, but since the iron group is at the peak of the binding energy curve, the fusion of elements more massive than iron would soak up energy rather than deliver it
Chloroplast: Structure and Function
The role of chloroplasts in photosynthesis has been illustrated below followed by a description of the roles of different components of chloroplasts The envelope of the chloroplasts is semi-permeable, and it regulates the entry and exit of molecules from the chloroplast. The internal portion of the thylakoid is called the thylakoid lumen, and contains plastocyanins and other molecules required for the transport of electrons
Photosynthesis--Light Dependent Reactions
As you might expect, the light dependent reactions depend on light; this is where the plant converts light energy to chemical energy in the form of ATP and electrons. A photosystem has a similar collection of pigment molecules that focus the energy to a reaction center where the electrons are ejected from the molecule
Chemical of the Week -- The Chemistry of Autumn Colors
The sugars produced by photosynthesis flow from the leaves to other parts of the tree, where some of the chemical energy is used for growth and some is stored. (The leaves of some trees, such as birches and cottonwoods, also contain carotene; these leaves appear brighter green, because carotene absorbs blue-green light.) Water and nutrients flow from the roots, through the branches, and into the leaves
After phosphorylation and reduction, what more needs to happen in the Calvin cycle? A) addition of a pair of electrons from NADPH B) inactivation of RuBP carboxylase enzyme C) regeneration of ATP from ADP D) regeneration of rubisco E) a gain of NADPH D) regeneration of rubisco feldman2009 Answered in Biology Chapter 10 In metabolic processes of cell respiration and photosynthesis, prosthetic groups such as heme and iron-sulfur complexes are encountered. Which of the following is a consequence of this? A) Formation of a moleculeof glucose would require 9 "turns." B) G3P more readily forms sucrose and other disaccharides than it does monosaccharides
Light Dependent Reactions - Biology Video by Brightstorm
So what basically happens is that energy in the form of light is absorbed by special pigments like I mentioned before called chlorophyll they pass that energy on to one of the central ones called the reaction center and that reaction center molecule can actually lose a couple of electrons and those electrons carry the energy away. So it flings away these high energy electrons and you can use the energy of those high energy electrons to do things, just like you use high energy electrons to make a fan move, your iPod to work or your TV to work
The Petition: A Global Warming Case - National Center for Case Study Teaching in Science
They typically include a summary of the case, teaching objectives, information about the intended audience, details about how the case may be taught, and a list of references and resources
The second photosystem that takes place is what is referred to as the NADPH Photosystem, in which electrons are moved from the chlorophyll to NADP-producing NADPH. Plants are also used in manufacturing products such as paper, lighting, adhesives, medicine, clothing, cosmetics, fuel, charcoal as well as many other products
Photosynthetic Stages and Light-Absorbing Pigments - Molecular Cell Biology - NCBI Bookshelf
The inner membrane, conversely, is the permeability barrier of the chloroplast; it contains transporters that regulate the movement of metabolites into and out of the organelle. The enzymes that incorporate CO2 into chemical intermediates and then convert it to starch are soluble constituents of the chloroplast stroma (see Figure 16-34)
Photosynthesis
These high-energy electrons will be used in the Calvin Cycle to reduce CO2 to make sugars The H+ is pumped into the thylakoid membrane to generate an H+ gradient (i.e. Each arrow in the diagram above actually represents a reaction like this one: Each element in the pathway is reduced by the electrons, and turns right around to reduce its neighbor in the pathway by giving it the electrons, thus becoming reoxidized and ready for the next electrons to pass through the photosystem H+ Pumping
BBC - Higher Bitesize Biology - Photosynthesis : Revision
Accessory pigments such as chlorophyll b, xanthophyll and carotene absorb light from other regions of the spectrum and pass the energy onto chlorophyll a. Page12345 Back Next More from Cell biology Audio Plants (mp3, 3.6 MB) Learn how plants harness the sun's energy using photosynthesis, and the factors which affect this process
Photosynthesis: The Role of Light
It is a homotrimer with each subunit in the trimer containing: 12 different protein molecules bound to 96 molecules of chlorophyll a 2 molecules of the reaction center chlorophyll P700 4 accessory molecules closely associated with them 90 molecules that serve as antenna pigments 22 carotenoid molecules 4 lipid molecules 3 clusters of Fe4S4 2 phylloquinones View structures of chlorophyll a, chlorophyll b, and beta-carotene, a carotenoid. The LHC-II of spinach is a homotrimer, with each monomer containing a single polypeptide 8 molecules of chlorophyll a 6 molecules of chlorophyll b 4 carotenoid molecules 5
The Light-Dependent and Light-Independent Reactions - Shmoop Biology
With so much positivity around, the protons get a little upset and try to equalize their distribution in the chloroplast by moving from the lumen to the stroma to reach equilibrium (read: equal numbers of protons in both places). When protons move down the gradient, with down referring to the direction of the area containing fewer protons, the protons are grabbed by enzymes that bring the protons together with the electrons from the electron transport chain
Photosynthesis
In the daytime, when the light reaction is occurring and ATP is available (but the stomates must remain closed), they take the CO2 from these organic compounds and put it into the Calvin cycle. Chlorophyll and several other pigments such as beta-carotene are organized in clusters in the thylakoid membrane and are involved in the light reaction
Though unicellular, amoebas have a nucleolus but not a nucleus and all the cell organelles except mitochondria, therefore fulfilling the characteristics of eukaryotes. Questions asked by the same visitorWhich of the following statements is true for a cell placed in beaker containing an isotonic solution? Weegy: Please provide the options
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