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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 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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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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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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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 ...


2

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 ...


2

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 ...


2

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 ...


2

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 ...


2

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 ...


2

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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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 ...


1

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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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 ...


1

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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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 ...


1

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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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 ...


1

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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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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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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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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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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