New answers tagged

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I am putting here the main points from the link given by @WYSIWYG (i.e. this): High glucose levels reduce the levels of the powerful vasodilator nitric oxide in blood vessels, a shortfall that increases the risk of high blood pressure and eventually narrows down the vessels...increased modification of proteins by a glucose-derived molecule is a player in ...


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These terms are completely unrelated. Alpha-subunit is an arbitrary name for a protein subunit in a multi-subunit protein complex (one having a quaternary structure like haemoglobin or G-protein etc). Alpha-helix is a type of secondary structure. Addition by David: For those who may be unfamiliar with this, alpha, beta, gamma etc. are Greek letters of ...


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I answered this implicitly in a comment to my answer to: Light and Dark Reaction of photosynthesis?. Anyway: There is no such thing as NADPH2. There is only NADP+ and NADPH. Consult Wikipedia or a reputable text such as Berg. The nicotinamide portion of NADP that undergoes oxidation and reduction is exactly the same as in NAD. The changes undergone are: ...


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It is a misconception that cats cannot synthesize taurine. Cats can synthesize taurine, just like other mammals, but not enough of it to make up for an entirely taurine-deficient diet. Cats (and other mammalian carnivores) would have consumed a taurine-rich diet in the ancestral environment. It is only when they are fed vegetable/fruit/grain-derived foods ...


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Plants use both water and air as food using photosynthesis where water is split and recombined with carbon dioxide from air to make glucose. Overall, the chemical reaction of photosynthesis is as follows: Light energy + plant enzymes 6CO2 + 12H2O ------------------------------------------------> C6H12O6 + 6O2 + 6H2O ...which means that it takes six ...


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You don't get energy from breaking chemical bonds, you only get energy from making chemical bonds, while breaking chemical bonds requires the input of energy. However, in practice chemical bonds are always broken as others are formed, and the net number of bonds is generally constant. Otherwise you would end up with free radicals, which are highly reactive ...


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Since this phenomenon has not been studied much, so it is difficult to give a definite answer. But still, I will post a possible explanation for this. I use the equation $S_2O_3^{2-} +2H^+ + 2e^- \to HS^- + HSO_3^{-}$ as you give in your question. From this wikipedia article, I can say that SRB need to convert $S_2O_3^{2-}$ to $SO_4^{2-}$ before using it ...


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Simply put. Plant growing from sugar (both energy and material). So if they could store sugar (or even find sugar from anywhere). They could grow even there are no sunlight And photosynthesis never make plant grow immediately. It just make sugar. And plant store it. Actually many plants grow at night while eating sugar it stored on daytime Some plant store ...


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E.coli use DNA polymerase for DNA replication too. Primase creates a short oligonucleotid (primer) in the start of string and DNA polymerase continues in work. RNA polymerase is using in synthesis of RNA molecules.


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I always used the book "Enzyme Structure and Mechanism" by Alan Fersht. (Structure and Mechanism in Protein Science: A Guide to Enzyme Catalysis and Protein Folding is the latest version, published in 1998.) Both in some courses I did and when working on (complex) enzymatic mechanisms. It's a classic (so a bit old maybe), but it covers all the basics and ...


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Before answering the question, I assume that the plant is somehow getting enough O2 to survive. There can be a number of variations in the answer depending upon the more particular situation you give. You can have a look here to see a list of factors affecting rate of photosynthesis in plants. I put graphs of factors important for this question: If we ...


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Biochemically, it appears it can, as some Algae can. The question is then whether there are any real plants who do it.


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According to the information you have provided isn't the starting equation: 1 x 10EE-8 = (0.9 x [R]) / 0.1 So you can solve for [R]? [R] = (1 x 10EE-8 x 0.1) / 0.9 I am not saying this is correct, but by substituting the values you provided isn't this how one would algebraically solve for an unknown? Maybe I am missing something(?) You state you wish to ...


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I can see your frustration if you meet errors such as NADPH2 but that is the price you pay for approaching as complex a subject as photosynthesis without a good biochemistry textbook. Even the on-line versions (e.g. Berg et al.) are unsatisfactory because of their layout. You will have to sit down and spend a couple of hours on the topic — all you can expect ...


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The flat arrows are a cartoon representation of β-strands (one type of regular hydrogen-bonded secondary structure). The direction of the arrow is the direction of the amino acid sequence (arrow head pointing towards the C-terminus). The thin wires are regions with no regular structure. There are also two small green spiral ribbons in the foreground left ...


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Light Reaction (also known as light dependent reaction) The light reaction uses chlorophyll (which is the main photosynthetic pigment) to capture light, and then uses the light energy to make ATP and NADPH. Water is also broken apart in this process so the electrons can be extracted, yielding hydrogen ions and oxygen gas. The stimulation of chlorophyll ...


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This is a homework question but I will answer it (forgive me moderators ;). You will get your answer from this answer: Sucrose and starch are more efficient in energy storage when compared to glucose and fructose, but starch is insoluble in water. So it can't be transported via phloem and the next choice is sucrose, being water soluble and energy ...


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The data you provide (in 1st paragraph) is about E.coli (correct me if I'm wrong) as I found similar data on Wikipedia: Much like β-oxidation, straight-chain fatty acid synthesis occurs via the six recurring reactions shown below, until the 16-carbon palmitic acid is produced. For the answer (emphasis mine): The diagrams presented show how fatty ...


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The reason that chlorophyll is green is because it absorbs other colors of light such as red and blue, so in a way the green light is reflected out since the pigment does not absorb it. Because life might have been purple: It is possible that the very first life form to process light may have been purple colored. This would mean it was reflecting red ...


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The authors obviously meant to write that the histones associated with the promoter become deacetylated. They cannot mean the promoter itself as that is DNA. What they wrote is not shorthand or acceptable alternative usage, but just a mistake — published papers often contain typos and mistakes of this sort. Probably the authors meant to write the ...


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See this paragraph and image from The Cell: A Molecular Approach. 2nd edition.: During passive diffusion, a molecule simply dissolves in the phospholipid bilayer, diffuses across it, and then dissolves in the aqueous solution at the other side of the membrane...Passive diffusion is thus a nonselective process by which any molecule able to dissolve in the ...


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Wikipedia tends to answer your question by this (emphasis mine): In F-ATPases, there are three copies each of the alpha and beta subunits that form the catalytic core of the F1 complex, while the remaining F1 subunits (gamma, delta, epsilon) form part of the stalks. There is a substrate-binding site on each of the alpha and beta subunits, those on the ...


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From: Uniprot Mitochondrial membrane ATP synthase (F1F0 ATP synthase or Complex V) produces ATP from ADP in the presence of a proton gradient across the membrane which is generated by electron transport complexes of the respiratory chain. F-type ATPases consist of two structural domains, F1 - containing the extramembranous catalytic core, and F0 - ...


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The α- and β-subunits have a similar fold, as would be expected from their sequence similarity. All of the α- subunits are bound to the ATP analogue AMP–PNP, and the three subunits adopt very similar conformations. The three β-subunits, however, are in three nucleotide-bound states: the first, termed βTP, has AMP–PNP in the catalytic site (FIG. ...


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As far as I know you can either adjust the ampere or the voltage as both is dependent of the resistance from the buffer. Which means that I would suggest you to let the voltage as it is. As the ampere = voltage / resistance and voltage = resistance * ampere and as you can see that the voltage has to get higher if the ampere is increased and the ampere has ...


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So, what is causing the higher degradation than usual? Is it the lack of the materials required to produce the receptor? Lack of materials is almost never the reason. Receptor turnover is actively controlled by different mechanisms. Ubiquitylation is one of the common mechanisms. Ubiquitylated receptors are internalized; these internalized receptors can ...


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Similarities Despite major overall differences, there are some basic similarities in the two processes: Light energy excites an electron to a higher energy level. A covalent bond is broken as the electron moves elsewhere. This process is called ‘photolysis’ and is purely chemical. Differences The difference is in what happens to the excited electron ...


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Nice question. I must say it took me many hours to get satisfactory answer. Hairs are made of keratin molecules, which contain cysteine. Cysteine has thiol (-SH) group, by which it can form disulfide (-S-S-) bond with another cysteine of another keratin, causing bending of hair. See this image from here: Curling of hair can be justified on both molecular ...


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What's interesting with this one is we don't really know very well the mechanism behind what's called chilling injury. It happens to a range of fruits, like bananas, peaches, avocado, or apples. The belief is that the chilling alters membrane permeability to storage vacuoles inside the plant cells. Try On Food and Cooking, pp.269, and Puig et al. (2015) for ...


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The answer to this, as said by @canadianer in comment, is that beta branched amino acids are bulky and can sterically clash with neighbouring atoms, forcing the backbone to adopt torsion angles which don't favour helix formation. I couldn't find reference for these exact words, but similar one here: amino acids such as Valine, Isoleucine, and Threonine ...


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It seems like the mistake is in complex III. Look at this image from here: It clearly shows the number of protons reduced in (and taken from) matrix and number of protons pumped into inter-membrane space. So the data becomes: Complex I: matrix: 2H+ reduced (from NADH + H+) + 2H+ pumped out IMS: 4H+ pumped in Complex II: matrix: 2H+ reduced (from ...


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I found this research paper (pdf) by D. Roger Illingworth, William S. Harris, and William E. Connor (Journal of the American Heart Association, 1984) that offers some help. Its abstract says: Diets rich in omega-3 fatty acids derived from fish oils lower the plasma concentrations of low density lipoproteins (LDL) and very low density lipoproteins in ...


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Althugh water vapor contributes to greenhouse warming of the atmosphere, changes in atmospheric water vapor tend to follow rather than drive changes in temperature. Also, in the form of clouds, atmospheric water can have a cooling effect on earth temperature. Clouds illustrate why water vapor, unlike carbon dioxide and methane, is not thought of as a driver ...


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We don't get it from the sun, it's synthesized. Humans can get it... via nutrition. via synthesis in the skin, which depends on UV radiation. Sun is the major source of it (the radiation, not the vitamin), and synthesis in the skin the major source of the vitamin. However, it needs further modification in the liver or kidney to become bioactive. UV ...


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Are there any proteins in the body whose surface is hydrophobic? Sure. Although you are right in thinking that most proteins have hydrophilic surfaces, some are very hydrophobic. My favorite example is Elastin, it is the main component of the skin which grants it elasticity. In fact, the hydrophobic nature of elastin is what confers it its function. ...



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