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Questions tagged [biochemistry]

This tag is for questions concerning biochemical methods (e.g. electrophoresis) or those concerning biochemical mechanisms or research. Do not use this tag if your question is merely about compounds often used in areas related to biochemistry or associated with these. These may fall under organic chemistry or the appropriate compound’s functional groups’ tags.

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What is the difference between oxalacetate and oxaloacetate?

What is the difference, if any, between oxalacetate and oxaloacetate? Is the former archaic nomenclature? Thanks
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17 views

E. coli biochemistry ? question or organic chemistry question [on hold]

If there is E. Coli in manure. And heating up E coli will kill it off. Would boiling/heating fresh manure kill any E. Coli permanently making it safer for a fertilizer. Or would it return and thrive.
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19 views

As a chemistry major, do you end up memorizing a bunch of biochemical signalling pathways instead of verifying them? [on hold]

I am curious to know if biochemistry majors learn these signalling pathways from a book over doing an experiment to verify what is being taught.
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17 views

How to recreate bioluminescence in fireflies in a lab?

I have several mg/mL of D-luciferin, luciferase (firefly), ATP solution (25 mmol) and MgSO4 (for the mg2+ ions). The experiment has to be done in cuvettes of 2,5 mL (if I get any results, it will be ...
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Typical proportions of alpha and beta forms of D-glucose in powder? [on hold]

does anyone know, if you order D-glucose, CAS number 50-99-7, from a source such as Sigma, is this a mixture of the alpha and beta forms and in what sort of proportions that mixture is likely to be? ...
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1answer
13 views

Valence electrons in DNA nucleotide addition [closed]

Can anyone explain the movement of valence electrons during the nucleophilic attack that occurs during DNA synthesis? The 3' oxygen starts with two lone pairs of electrons but what happens during the ...
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2answers
35 views

Help required for the calculation of moles [closed]

If 4.5ml of yeast prep + 0.5ml of 0.25 M glucose is separated into 2ml in 2 similar flasks. How many micromoles of glucose are there in one flask? Using M1V1=M2V2 (0.5ml/1000)*0.25M = M2 * 2ml = 0....
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19 views

why do cone cells have broad responsivity spectra peaks?

My understanding of vision is that, although the cone cells in our eyes can detect three colors, there is enough overlap in the responsivity spectra (as shown here: https://en.wikipedia.org/wiki/...
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2answers
86 views

How to determine steady state of multi-step reaction with both reversible and irreversible steps?

I am trying to determine the relative concentrations of $\ce{U1}$, $\ce{U2}$, and $\ce{E}$ when the following reaction is at steady state. Note that $k_t$ is the zero order rate constant of new $\ce{...
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0answers
22 views

How can the ocean act as a buffer?

I was reading up on the buffering effect of the ocean and I was quite confused about how the buffer is able to do anything. The buffer I will refer to is below: $$\ce{CO3^{-2} +H2O <=> HCO3 + OH^...
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2answers
79 views

How does existence of alpha and beta form of glucose prove that it exists as a cyclic structure

My book says that Glucose is found to exist in two different crystalline forms which are named as $\alpha$ and $\beta$. Next it says that This behaviour could not be explained by the open ...
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1answer
54 views

Why is copper(II) sulfate added drop by drop during the Biuret test?

The Biuret test is a test for proteins. The procedure is to add a strong base, such as NaOH, to dissolve the protein. After that, copper(II) sulfate is added drop by drop into this until a (violet) ...
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2answers
53 views

Measuring a high Michaelis constant using fluorescence

We have the task of measuring kinetic parameters of an oxidase reaction that has a $K_M$ of about $2 \,\text{mM}$. For that, we want to use a fluorescence assay based on Amplex Red. The latter is a ...
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1answer
25 views

Can someone suggest me method to extract carotenoids? [closed]

I want to extract carotenoids, but want to use some inexpensive method. can you suggest me some method?
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1answer
43 views

Why would decreasing ionic strength of buffer disrupt hydrogen bonds

I'm reading about cDNA synthesis in my textbook and it mentions that: The captured mRNAs are subsequently released and collected, for example, by decreasing the ionic strength of the buffer so that ...
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2answers
39 views

What happens during Glycolysis? [closed]

Can I get brief explanation of the reactions that occur under Glycolysis? What do the curved lines represent?
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1answer
39 views

Complementary base pairing

In the molecular structure of a DNA it is seen that purines (adenine and guanine) bind with pyrimidines (cytosine, uracil and thymine) through hydrogen bonds, and this is always between a purine and a ...
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0answers
34 views

What's causing this dip in the FCS curve?

This is a fluorescence correlation spectroscopy measurement of light harvesting complexes. What could be causing the dip at 100 microseconds? Edit: The same thing was observed using fluorescence ...
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1answer
55 views

Make paper from hair? [closed]

Hair is fibrous... Is there a good reason, why we don't recycle our own hair (and clothing, what have you) into paper-products? (rather than cutting down trees)?
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1answer
44 views

What would happen if we had a different kind of metal in our bloodstream? [closed]

It is a common fact that we have iron in our blood. But what if we had something different in its place? Like instead of iron what if it was copper, or silver, or what if we had gold in our blood ...
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1answer
42 views

Opening the imidazoline ring in tolazoline

Hello. I was studying about the alkaline ring opening or purines. While doing research, i came across this compound. This got me thinking if we can use the same procedure to open the imidazoline ring ...
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2answers
89 views

Why does bond breaking in ATP release energy? [duplicate]

We always come across that formation of bonds releases energy, and bond breaking requires energy, but in the case where ATP converts into ADP or AMP (bond breaking), energy is released. Why? Further, ...
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1answer
28 views

Acid value of linseed oil

For this we weigh $\pu{1.015 g}$ of linseed oil which is dissolved in alcohol. 3 drops of phenolphthalein (pH indicator) are added and a solution of potassium hydroxide of concentration $C = \pu{9.5e-...
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0answers
24 views

How many natural products are there in existence? [closed]

Hi I'm doing a project on natural products and I'm wondering if somewhere there is at least an estimated number of how many exist? If this exists somewhere can you please provide a reference. ...
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1answer
109 views

What do the dots mean in HN.CO.CH3 connected to the second carbon of N- Acetylglucosamine? And what do the N and acetyl indicate?

What do the dots mean in HN.CO.CH3 connected to the second carbon of N- Acetylglucosamine? And what do the N and acetyl indicate?
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1answer
17 views

EtG formation outside the liver

Ethyl glucuronide (EtG) is formed by conjugation with glucuronic acid catalyzed by the enzyme UDP-glucuronosyltransferase. My question: Is it possible for EtG to form spontaneously in a urine sample ...
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1answer
34 views

Why does a lowered dielectric constant cause RNA/DNA precipitation in ethanol precipitation?

For ethanol precipitations, as mentioned in https://en.wikipedia.org/wiki/Ethanol_precipitation, given that the attraction of water molecules to charged ions like phosphates is based on Coulombic ...
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1answer
31 views

Are enzymes with superior catalytic properties more sensitive to temperature changes?

I am wondering whether enzymes with superior catalytic properties are more or less temperature sensitive than average enzymes. I know that enzymes lower the activation energy, Ea. So the more ...
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0answers
67 views

When the present state of knowledge concerning central noradrenergic transmission was established?

Some time ago I began to search for descriptions of the mechanisms responsible for the regulation of noradrenergic transmission in the central nervous system of man and to my great surprise the most ...
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0answers
13 views

Lipophilicity computational prediction

Is there a web based (or otherwise) computational chemistry tool which is able to calculate lipophilicity of a given compound?
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2answers
33 views

What's the use of adding 73 mM H2O2 to a supertanant? [closed]

Enzyme assays Determination of catalase specific activity The CAT (EC 1.11.1.6) enzyme activity was measured according to Gallego et al.38 Plant samples were grinded in $\pu{0.1M}\ \ce{...
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0answers
30 views

Mobility of Cations in the Environment

I have recently performed an experiment in which I tested the affects of phytotoxic cations on the rate of germination of the common navy bean. I did this out of curiosity, as I have recently been ...
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2answers
2k views

Why is arsenic toxic to humans?

I don't understand why arsenic is toxic and why it does damage to humans. Could it be that it is so similar to phosphorous? If so, would that make antimony toxic as well?
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0answers
61 views

What is the purpose of tetrazole in oligonucleotide synthesis?

The ATDBio book on nucleic acids describes tetrazole as an activator required to couple nucleotides. The diisopropylamino group of the nucleoside phosphoramidite is protonated by the activator, ...
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1answer
78 views

What does it mean to equilibrate a column in size exclusion chromatography and why is a buffer used?

I'm reading a procedure on size exclusion chromatography and it says that the first step is to equilibrate the column with buffer. What does this mean?
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Why absorption changes in schiff-base formation? Coenzyme PLP

Pyrodoxal-5-phosphate (PLP) in enzymes form schiff-base to lysine residue. This can be detected by the change in the absorption from 390 nm to 420 nm (free PLP to stiff-base bound PLP). I remember ...
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0answers
25 views

Does oxidation of fatty acids through the process of ketosis versus direct beta oxidation change ATP production?

When insulin levels are low, the liver begins to oxidize fat. The liver oxidizes fat by an incomplete process that yields ketone bodies. The incomplete oxidation of fatty acids by the liver yields ...
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1answer
41 views

What citrate is a common anticoagulant?

When I underwent plateletpheresis, something that the staff called "citrate" was added to my blood as an anticoagulant. Everything I can find about this product online refers to it as just "citrate". ...
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2answers
51 views

Are the stereoisomers of nucleosides actually anomers?

An anomer is an epimer at an (hemi)-acetal carbon like $\ce{R2C(OR')2}$. Why is the 1'-position of a nucleoside referred to as the anomeric center despite the lack of acetal functional groups?
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0answers
28 views

What would be the weight loss equation be for Ketosis? [closed]

This is the formula for how the body uses fat: $$\ce{C55H104O6 + 78O2 -> 55CO2 + 52H2O + energy}$$ From this video: What would be the equivalent formula for Ketosis?From my research ketones can ...
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1answer
39 views

Which is more soluble in water ammonia or Sodium dodecyl sulfate

I've tried looking this up and can't seem to find the solubility of SDS if any one knows the answer I would really appreciate it. Which is more soluble in water ammonia or Sodium dodecyl sulfate. ...
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0answers
33 views

What do cannabinioids have in common structurally?

I'm looking at the wikipedia page for cannabinioids, and trying to find structural similarities between them. For plant based ones it's hard enough, the only similarity I could find seemed to be 6 ...
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0answers
14 views

What is the life span of MLV (multilamella lipid vesicle) dry film?

This suits better as a biochemistry question. Use this method to to produce multilamellar lipid vesicles. Usual life span of extruded, suspended lipid vesicles are less than 36 hours. There's a ...
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2answers
88 views

How does the human body deal with free radicals it creates itself?

I know that free radicals are created all over your body all the time as a byproduct of its chemical processes, (or maybe I do not and that is false). However I am confused about the distinction ...
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1answer
35 views

Can Molisch test be used to separate monosaccharides from polysaccharides?

Do the results of Molisch test on monosaccharides have any differences with when it's done to disaccharides or polysaccharides?
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2answers
108 views

Why are some ions mutagenic and others are not?

It is my understanding that when ionic species (such as $\ce{He^2+}$, or alpha particles) enter the human body, they tend to react with biomolecules, causing damage by (for example) mutating DNA. If ...
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1answer
26 views

What is a protein interface account? [closed]

I'm not a specialist but I'd like to get into meaning of what is written in some articles. In the sentences: "The large numbers of salt bridges and hydrogen bonds in the protein interface account ...
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2answers
329 views

What's the effect of temperature on buffering capacity?

I did some research online but I still couldn't get any conclusion. Some said that the buffering capacity decreases when temperature increases because of the increase in ionisation of the weak acid ...
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0answers
134 views

redox signaling molecules and electrolysis

There is a product whose presentation screams of snake oil, allegedly consisting of nothing but electrically treated salt water. The product is claimed to be chock full of "redox signaling molecules" ...
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1answer
278 views

Is chitin actually protein?

Recently insects are featured as a protein rich source for human nutrition. That humans can really digest chitin through chitinase enzym has been only recently confirmed. But, does the chitin shell ...