The study of chemistry within the scope of biology: the compounds that occur and the reactions involving them in living organisms.

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150 views

Why do bananas go brown quicker in the fridge?

Perhaps the title should be: Why do specifically bananas go brown quickly when left in the fridge? Bananas go brown over time because of the oxidation of phenol residues. Bananas go brown quicker ...
4
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32 views

How do disulphide bonds in hair cause curling?

I understand that the asymmetrical distribution of disulphide bonds in hair cause curling, but do not completely understand why this causes an inherent curl on the macroscopic level, for several ...
4
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0answers
34 views

Is it possible to isolate and analyse intermediates of protein folding?

I would like to know if there is an assay which could allow us to analyse a protein before it has assumed its 3D functional form. While studying structural biology, I only came to know the forces that ...
4
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0answers
118 views

How do omega-3 fatty acids reduce cholesterol at the molecular level?

I have heard that omega-3 fatty acids found in fish are a good way to prevent/reduce cholesterol problems. My question is how do omega-3 fatty acids do that: what are they doing on a chemical level ...
4
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0answers
31 views

Does Doxylamine have any Influence on the Monoaminergic System?

Does doxylamine have any affects on the monoaminergic system? Specifically I am interested in adrenergic or serotonergic activity but additional information on its dopaminergic activity won't hurt ...
3
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0answers
45 views

How many protons are pumped out per pair of electrons from NADH in oxidative phosphorylation?

I have searched the web and found that 10 protons are suppose to get pumped out during the electron cycle, but i'm a bit confused. I'm trying to count, for every complex(1/3/4), the number of protons ...
3
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0answers
50 views

What Chemical Trigger Causes Ectomycorrhiza To Change From Asexual To Sexual?

I am searching for the catalyst behind the change of asexual to sexual ectomycorrhiza when symbiosis with a tree root is formed. As ectomycorrhiza attaches itself to a root, they form a relationship ...
3
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0answers
106 views

Can I leave BL21(DE3) cells in room temperature?

I am preparing competent cells, and I finished inoculating a single colony in SOB. It has been incubating at 37 degrees Celsius for almost 16 hours since, and it's getting very late where I live. I ...
3
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0answers
67 views

How does estrogen influence collagen synthesis?

Through what mechanisms does estrogen interact with collagen synthesis? Especially in the context of elevated estrogen levels and genesis of purpura simplex .
3
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51 views

How does beta branching stop alpha helices from forming?

I am told that beta branching interferes with alpha helix formation. Problem is that I don't see how beta branching has anything to do with alpha-helix formation. Beta-branches are on the outside of ...
3
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0answers
42 views

What are the biological mechanisms of candy causing nausea?

As I sit here after eating too much chocolate, I wonder: What are the biological mechanisms behind eating too much candy candy causing nausea in a healthy individual? Is it a spike in blood sugar, ...
3
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60 views

Synthesis of Fatty Acids Longer than 16 Carbons

I understand that the human body when performing Fatty Acid Synthesis can synthesize only until C16 (palmitate). However the ER has desaturases and elongases. I know that desaturases are used to add ...
3
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105 views

What is the biochemical pathway of fluoride?

Fluoride is a common active ingredient in tooth paste to prevent dental caries. It is also added or removed from the water supply in some communities for the same reason, but in children only. My ...
3
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247 views

Virucides - Herbal and otherwise, for HHV6 type virus or any inner-cell virus

Does anyone know where I can find a reliable list of virucides (not anti-virus) that can be used by humans? This virucide must be able to affect viruses that are already inside the cells. St John's ...
2
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0answers
51 views

What is the advantage of using plant-derived antibacterials rather than bacteria-derived antibacterials?

So obviously we have a big problem with antibiotic resistance. Most of our antibiotics originate from bacteria themselves (or are synthetic variations on scaffolds which originate from bacteria). I ...
2
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0answers
32 views

PCR that worked previously is now only showing primer dimers and a smear on gel

PCR amplification of a promoter sequence for gel extraction worked beautifully using Phusion HF enzyme with GC (higher error but less picky) buffer. However, DNA concentration from the gel extraction ...
2
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0answers
36 views

Nail polish toxicity studies?

Are there any well-founded studies that authoritatively demonstrate negative effects from the use of nail polish, particularly in children? I've been brought into the fray of a couple of folks who ...
2
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0answers
40 views

Lipid-soluble vs. water-soluble substances through the membrane

It’s said that water-soluble substances can enter the cell membrane with less ease than lipid-soluble substances because the former encounters impedance in the hydrophobic region of the phospholipid ...
2
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43 views

Proteases in the blood

I’m reading on hormones and the book talks about how peptide or amine hormones are easily broken down by proteases present in the blood plasma. This has led me to question the interactions between ...
2
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0answers
54 views

Textbook for quantitative biochemistry with thermodynamics, as an alternative to Voet, Voet & Pratt (Fundamentals of Biochemistry)?

I'm looking for a great textbook on biochemistry that covers core topics: relevant aspects of thermodynamics, reaction kinetics, metabolism (e.g. krebs cycle, respiration, etc.). Ideally it would also ...
2
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0answers
31 views

What are all of the currently known variations of the G zipper motif?

The G zipper motif is found in transmembrane proteins at an above random frequency and there are models explaining how it might help with multiple transmembrane intra-membrane helix bundle assembly. ...
2
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0answers
29 views

Does blood typing still provide a use for ancient tissue analysis?

Modern techniques. In recent years, DNA sequencing has become extremely cheap. This, compounded by the ability to PCR miniscule samples to viable samples for analysis, means that aDNA can be ...
2
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0answers
67 views

Which method would more accurately help to identify the unknown concentration of a protein sample between the A280 and the Bradford methods?

I quantified my protein using the standard Bradford method and the A280 methods and obtained values that were far off from the theoretical value of the protein of interest, and therefore was wondering ...
2
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0answers
56 views

Zinc and brewer's yeast

I'm hoping for some information relating to yeast nutrition (specifically Saccharomyces cerevisea) in beer fermentation. Zinc is well-known to be necessary for yeast cultures to perform successful ...
2
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0answers
21 views

Which biosynthetic pathways take place in the plastid and were are they located?

I know that the isoprenoid, jasmonate, glucosinolate, fatty acids, chlorophyll, starch, and aromatic amino acid syntheses are located in the plastid. But I don't know if they are located in the ...
2
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0answers
83 views

What are the ingredients of Pheromone Trap using for controlling Fruit flies of cucumber?

Pheromone Traps are used for fruit fly control. But I have no idea which ingredients or chemicals are used for preparing Pheromone trap
2
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0answers
58 views

Is an antivenom venomous?

What happens when someone takes an anti-venom for an animal they weren't bit by, either for incorrect identification of the animal they were bit by or if they weren't bit at all? I am looking for the ...
2
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0answers
83 views

Why is a nicotinamide-tryptophan combination used to treat affective episodes in a few older clinical trials?

At least one of the journal articles that reported on such clinical trials allured to the nicotinamide-tryptophan pathway that I assume must be related to the metabolism of tryptophan into serotonin ...
2
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0answers
208 views

What tests can be performed to test the purity and quality of the raw peptide HCG (Human Chorionic Gonadotropin)

What tests could be run to test the purity and type of HCG? We are looking to purchase HCG from China but the purity and quality varies between labs, we are able to receive samples of the raw peptide ...
2
votes
0answers
279 views

Can Pfx polymerase add only one 3' A overhang?

I am trying to clone a PCR product that was amplified using Pfx polymerase into pGemT vector. I had to A-tail the PCR product using Taq polymerase since Pfx only generates blunt end products. My ...
1
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0answers
6 views

Function of NEZHA gene

What is the function of NEZHA? What effect does it have on microtubules and PLEKHA7? What happens after it has been knocked down?
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0answers
17 views

Convert flux value in nmol/min/mg protein to nmol/min/cell?

This is a question about unit conversion. I found an experimental measurement of the saturation uptake of glucose in yeast: $$V_\textrm{max} \approx 650 \textrm{nmol}/\textrm{min}/\textrm{mg ...
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0answers
22 views

Is it possible to separate the binding and catalysis of an enzyme in two steps?

Is it possible to do the following: Enzyme E binds to its substrate S without catalysis; Add a controllable stimulus, such as light, adding or removing chemicals; The enzymatic reaction is triggered ...
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0answers
27 views

Assays to determine competitive binding versus non-competitive

I'm looking for both simple and complex assays or technologies than can be used to determine if two competing molecules are competitive or noncompetitive. I figure xray crystallography is a clear ...
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0answers
21 views

How do microbes develop resistance to anitmicrobial peptides?

I would like to better understand how bacteria use the "strategy" of alternations to lipid A and membrane proteins in order to resist antimicrobial peptides of the immune system? It is my ...
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0answers
17 views

Yew seed dormancy reduction

Yew seeds have very long dormancy when artificially planted. They are also adapted to passage through digestive systems of animals that eat/transport them. But could the dormancy be shorter (or the ...
1
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0answers
31 views

How much energy would it cost to synthesize all cholesterol requirements de novo?

Imagine a scenario in which some person is unable to absorb any dietary cholesterol because of some intestinal mutation (for example). Thus, they have no cholesterol available from their diet for ...
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0answers
23 views

Is pathlength correction vital to be included while quantifying protein

I am trying to quantify protein in serum/plasma samples. I have carried out biuret assay for my samples using microplate reader. While performing I encountered the doubt whether I should include ...
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0answers
20 views

How is the enzyme glycogen synthase regulated?

How is the enzyme glycogen synthase regulated in regards to glycogen synthesis? I think I understand that phosphorylation decreases its activity (through glycogen synthase kinase?), but what role do ...
1
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0answers
35 views

Which Lactobacillales (Lactic acid bacteria — LAB) strains are capable of degrading starch?

I've been researching bacteria strains but am having trouble finding amylolytic LAB strains with amylolytic and lactic acid producing character. The only species I've found, that are capable of ...
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0answers
35 views

Birth control hormones in the water? Or not?

This prior question talks about natural estrogen (TL;DR: Months to years): How quickly do estrogens break down in the environment? Ref: http://dx.doi.org/10.1038/485441a A lot of media has said, ...
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0answers
38 views

Can I explain the kinetics of a ligand looking at the ligand-protein co-structure?

Can I explain the kinetics of a ligand binding to a target protein (association and dissociation rates) by looking at the protein-ligand co-structure? Editing my question after a few comments: I ...
1
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0answers
20 views

Differences in structural target for LPS detection by LAL and MD-2/TLR4

I remember there being a significant difference in the pathogen-associated molecular patterns (PAMPs) used for detection of lipopolysaccharide (LPS) by mammalian cells and the Limulus amoebocyte ...
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0answers
19 views

Would it be possible to regulate proper phosphorylation so the UPR wouldn't initiate a reactionary cell death in important cells?

In studying the correlation of folded versus unfolded proteins and their impact on neuro-degeneration, it looks like improper phosphorylation in the chaperones (at least, in part) causes the ...
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0answers
47 views

aluminum sulfate vs (NH4)2SO4 in Colloidal Coomassie Staining Sol

I have been interested in Colloidal Coomassie Staining to detect proteins in PAGE gel. I found 2 different recipes: one of them uses aluminium sulfate, the other, (NH4)2SO4. I am wondering about ...
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0answers
21 views

Does the use of a Thiazide diuretic affect the ability of a hair follicle to absorb substances?

Thiazide diuretics are on the World Anti Doping Agency's, as well as the International Olympic Committee, list of banned substances due to it ability to mask illegal substances in urine. The rapid ...
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0answers
52 views

Cannot conjugate Biotin-labeled DNA to Streptavidin-labeled solid surface

I have been trying to immobilize DNA by the bioconjugation of biotin and streptavidin, but I cannot get this work. I added EDC and streptavidin to COOH ...
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0answers
24 views

Sequence based method for prediction of continuous B cell epitope

What is Sequence based method for prediction of continuous B cell epitope? What is the algorithm/procedure of this method? Can someone please explain this to me in simple language?
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54 views

Can non-carbonated energy drinks boost alcohol intoxication?

I just read news article about banning caffeine in alcohol drinks and about that energy drinks increase the urge to drink alcohol. Energy drinks cause sugar intoxication - answer about it here ...
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55 views

Vitamin D oral intake, transportation and absorption

Several factors affecting vitamin D and its active form absorption and storage acidity of stomach (not significant effect) cytopathic effects of viruses cytopathic effects of bacteria where the ...