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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1answer
66 views

Membrane potential in gram negative bacteria

Does the membrane potential usually quoted for gram negative bacteria (e.g. E. coli) refer to the potential across both membranes? - If yes, then does the potential fall more over the inner or outer ...
1
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1answer
60 views

Background correction when reading ELISA with TMB substrate

I'm doing some ELISA development, and I'd like some justification/best practices for background correction. I'm using a horseradish-peroxidase (HRP) detection system along with a TMB substrate and an ...
7
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0answers
66 views

What is the transmembrane 'Positive-Inside Rule' nowadays? Has the definition changed over time?

First definition. Two publications by von Heijne in 1989 and 1992 coined the 'Positive-Inside rule' and showed it's practical value in topology prediction of transmembrane helices. It was clearly ...
4
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0answers
27 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
37 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
26 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 ...
3
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0answers
34 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
votes
0answers
31 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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0answers
101 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 ...
3
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0answers
212 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
24 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
24 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
68 views

What biological processes can affect the temperature of the shadow a tree casts?

Assuming two trees have similar shape and leaf coverage, could differences in the biological processes among them lead to differences in the temperature of the shadow they cast? What biological ...
2
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0answers
25 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
46 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
votes
0answers
48 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
62 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 .
2
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0answers
19 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
45 views

Fatty Acid Synthesis of Fats Longs than 16 C

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 ...
2
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0answers
76 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 ...
2
votes
0answers
69 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
votes
0answers
56 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
votes
0answers
70 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
174 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
224 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
vote
0answers
32 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 ...
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0answers
17 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
18 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
20 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 ...
1
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0answers
18 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 ...
1
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0answers
33 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
23 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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0answers
48 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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0answers
49 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 ...
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0answers
27 views

Is life in a supercritical fluid possible?

Someone claimed that the dinosaurs could only live because back then athmospheric density was around 650 kg/m³, providing some buyoncy, this claim is checked on Skeptics SE. The claim itself is beside ...
1
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0answers
62 views

Ferredoxin synthesis pathways

I have been thinking about some alternative CO₂ fixation pathways. As almost all of them include ferredoxin reduction I started to wonder where does the ferredoxin comes from. I could not find any of ...
1
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0answers
62 views

Why does the ovum prefers to be arrested at metaphase 2 of meosis before fertilization? What is the possible advantage of this process?

Why does the human ovum prefers to be arrested at metaphase 2 of meosis before fertilization? What is the possible advantage of this process??Please help me with it.
1
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0answers
62 views

When a Lysosome's bonding sites all get bonded to, what is the most resource and energy efficient way to handle the used Lysosome?

Let's say a Lysosome that bonds to a hazardous material to neutralize it has all bonding sites used up. would it be more safe / efficient to excrete the entire Lysosome / hazardous material molecule ...
1
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0answers
151 views

How do cells slowly degrade 5,5'-dibromo-4,4'-dichloro-indigo?

5,5'-dibromo-4,4'-dichloro-indigo is the product of X-gal cleavage, often used as a reporter with B-galactosidase. I've made the (unreferenced) observation that it seems as though the blue product ...
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0answers
15 views

Is it possible to measure Secondary Bile Acid Kinetics?

Is it possible to measure secondary bile acid kinetic and flux measurements in vivo? Anyone have any experience with this sort of technique?
0
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0answers
18 views

Help with STRING database

How can I generate a graph on the STRING web server for physical interacting proteins only? I know we could extract the data and use Cytoscape to create a graph, but I would prefer to have a graph ...
0
votes
0answers
8 views

What is isomeric threshold and isomeric count?

Found the terms isomeric point and isomeric threshold in the following paper: http://lib.gen.in/ocean/9064caa3202a71977f338ecb430280a7/10.1007%40s12539-012-0119-8.pdf It siad that the isomeric point ...
0
votes
0answers
38 views

Why doesn't the body optimize how many fatty acids it burns?

Ketone bodies are produced due to an excess of fatty acids being burned (accumulation of acetyl-CoA) so my question is: Why doesn't the body simply regulate how many fats it burns so it doesn't have ...
0
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0answers
21 views

Where does the oxygen and water produced from the decomposition of hydrogen peroxide by catalase enzyme go?

How are they disposed of by the body, or are they disposed of at all? Since our body needs water and oxygen anyway, I'm speculating that these "waste product" will be reused/recycled by the body in ...
0
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0answers
46 views

What is the probe that absorbs at 450nm in the presence of NADH in this assay?

The colorimetric assays by Biovision and Sigma Aldrich seem to utilise a probe that binds to or reacts with NADH in order to cause absorbance at 450nm which can then be quantified by a ...
0
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0answers
47 views

How to measure concentrations of different metals from the environment?

Suppose that different kind of metals and chemicals (e.g. magnesium, sodium, copper) got transmitted to environment e.g. as a cause of an accident. How would measure the levels of those metals and ...
0
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0answers
18 views

To Study Interactions of two molecules in PubChem

Assume you have two substances Diosminum / Hesperidinum. The former strengthens vascular walls. The latter has role in some glycoside biosynthesis. From Biochemistry, I recall that glycodises have ...
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0answers
52 views

Substrate specificities of GPPS, FPPS and GGPPS (isoprenoid biosynthesis enzymes)

I have some questions related to isoprenoid synthesis enzymes. Does Geranylgeranyl pyrophosphate synthase (GGPPS) contribute in Geranyl-Pyrophosphate (GPP), Farnesyl pyrophosphate (FPP) and ...
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0answers
37 views

Importance of Biodegradation pathway over other pathways

What is the importance of biodegradation pathway over other pathways? This question occured when I saw this paper: Fenner K, Gao J, Kramer S, Ellis L, Wackett L. Data-driven extraction of relative ...