Questions tagged [chemical-biology]

Questions about the application of chemistry to interrogate and modify biological systems and processes.

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1answer
21 views

What exactly is peptone (tryptone?) and why does it not get precipitated?

According to Wikipedia Peptone (also called Tryptone) is a form of amino acid that has been treated by stomach acids. According to Google it also stays in solution when treated with acids or heat. Why ...
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1answer
41 views

Why is PLGA so expensive in comparison to PLA?

A Google search has lead me to believe that PLGA goes for anywhere between 8 USD and 100 USD per gram. Meanwhile, for PLA (3d printer grade), prices float around 50-100 USD per kilogram. I understand ...
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29 views

What specific toxins are formed during deep frying? And how (chemically) do they attack the body cells? [closed]

From what I understand, deep frying causes the oxidation of lipids into advanced lipid oxidation products. When these are consumed and metabolized by the body, they release ROS or free radicals which ...
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1answer
26 views

How does sodium rosinate enhances lathering property? [closed]

Why don't we use sodium carbonate or sodium stearate? What does sodium rosinate contain that the other two don't?
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1answer
76 views

Prostaglandin Nomenclature

Prostaglandins are lipid substances derived from fatty acids, which act as powerful biochemical regulators. In Wade's Organic Chemistry, they indicate that there are several families of ...
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1answer
25 views

carbon dioxide and its behaviour in acid base balance [closed]

In human body acid base balance, why and how does the dissolved carbon dioxide increases the hydrogen ion concentration with increasing in its partial pressure..? At the same time bicarbonate ion is ...
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1answer
29 views

Preferred IUPAC name of Protoporphyrin IX

I was looking up protoporphyrin IX and was surprised to find that no two websites gave the same IUPAC name for the compound. Here are some examples: 3,3'-(7,12-Diethenyl-3,8,13,17-...
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3answers
468 views

Net production of CO2 in plants

I am trying to understand in a qualitative way photosynthesis. I am not a chemist so please have some patience. I read on the Wikipedia page for photosynthesis that the way plants use $\ce{CO2}$ is ...
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1answer
36 views

Indirectly Measuring Diffusion of NO2 into Water

I am working on a data science project with the central hypothesis is that air-born pollutants can become water-born through diffusion. The example I am using as a proof of concept is $\ce{NO2}$. The ...
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0answers
48 views

Protein concentration in the cell from concentration in nucleus and cytoplasm [closed]

I have two quantities obtained by simulation. One represents a protein concentration in the nucleus, say $X_N$ and the other the same protein concentration in the cytoplasm , say $X_C$. I have real ...
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1answer
14 views

Effect of pH on sulphur isotope variation on a landscape

I recently ran a forest regression model, this model showed me that increasing soil pH increases sulphur isotope variation across the landscape. I am not how this is possible and if it makes sense
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1answer
40 views

Is hydroxychloroquine an anti-psychotic drug? [closed]

Is hydroxychloroquine an anti-psychotic drug or psychotic drug?
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2answers
54 views

What is meant by position 5' or 3' [closed]

I'm a self-learner that likes to keep up with current research. However, I can't find what is meant by expressions such as 5' or 3' positions on chemical structures. But , in particular, what is meant ...
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1answer
51 views

Chemical Formation Of A Virus [closed]

Many articles and books classify virus as a non living thing which only replicate itself inside a living host, yet some describe virus as a living organism. Virus was first discovered on the year 1892 ...
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3answers
304 views

How can an Organic chemist know the chemical formula of a natural product she isolated from an organism? [closed]

As a non scientist I several times wondered how can an Organic chemist successfully isolate a single molecule which a natural product of an organism; Whether a plant-part/mushroom-part/algae-part or a ...
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15 views

Oxidative phosphorylation analogue

Does the salt bridge in galvanic cells resemble the ATP pump in the inner mitochondrial membrane? And if yes than did someone use this pH difference in harvesting this energy?
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2answers
29 views

Why is it important to remove the used up electrons in oxidative phosphorylation?

I get that oxygen is the terminal electron acceptor in oxidative phosphorylation. But why is it essential to accept these electrons and remove them as $\ce{H2O}?$ Oxygen is essential for cellular ...
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43 views

Is there a software that can predict the shape of a custom protein, given its amino acid sequence?

I know that the internet is full of enzyme and protein simulators which can show active site and 3D structure (like bioblender), but the problem with these programs is that they use predefined ...
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1answer
61 views

A question about thiamine [closed]

How does the the nitrogen of thiazole in thiamine acquire a positive charge without being stabilized by another negative charge or by being a salt of an anion?
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22 views

A question about nicotinamide adenine dinucleotide

In the structure of NAD+, why does the nitrogen of pyridine bind covalently to the the first carbon of glucose while the anion stabilizing the nicotine amide ion is the phosphate group? In other words,...
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0answers
23 views

Pyridinium ion in inositol nicotinate

I have read about inositol nicotinate which is used as a medication for deficiency in vitamin B-3. I think that if acetic acid was applied to this medication it would form pyridinium ion and acetate ...
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2answers
393 views

How does one tell (or conclude) if a substance is carcinogenic?

It's common to read statements like: Tetrachloroethene ($\ce{CCl2=CCl2}$) was earlier used as a solvent for dry cleaning, but since it contaminated ground water and is a suspected carcinogen, ...
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0answers
58 views

Stable physiological buffer to make NAD+ solution

I was wondering what would be the most stable physiological buffer for nicotinamide adenine dinucleotide (NAD+), for potential storage as frozen aliquots - 6 months stability or around there would be ...
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1answer
307 views

Antiseptic role of kerosene

When I was kid and got a huge cut on my finger, I remember my grandmother putting lots of kerosene on my wound, as there was no health facility around. I want to confirm. Do chemists agree on the ...
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1answer
47 views

what wavelength should I use to measure the transmittance of iodine colouring? [closed]

I am doing an experiment on how pH buffers may affect amylase's break down of starch into glucose in a starch solution. I am using iodine reagent to identify how much starch is left after amylase is ...
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3answers
2k views

Why does radiocarbon dating only work in nonliving creatures? [duplicate]

I understand how carbon dating works, though I do not understand why it doesn't happen while a creature is living. Because while we are alive we still have carbon 14 in us, so shouldn't it work?
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17 views

Epoxy-silane-coated glass applications or the preparation or quality control for the silanized glass

The task is to make myself (3-Glycidyloxypropyl)trimethoxysilane (GMPTS for short) covered microscope slides to immobilize antibodies. Each time I cover the freshly prepared slide with Ab, I get ...
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2answers
49 views

transpiration of trees and the cooling of the air

The change from the liquid state of water to the water vapor requires a large latent heat to loosen the hydrogen bonds. The process of transpiration in the plant involves exactly this change of state. ...
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0answers
27 views

Fat polymerization vs hydrolysis and temperature change

I have an experiment on fats that I have to do in a few hours and I am very lost between fat/oil (lipid) polymerization due to high temperatures and hydrolysis. It appears that both result in the ...
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1answer
34 views

How to compute the number of ATP molecules that can be produced from breaking down an unsaturated free fatty acid?

From studying $\beta$-oxidation of free fatty acids, I've learned how to compute for the ATP equivalence of even-chain and odd-chain free fatty acids. What really bothers me now is how to compute for ...
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1answer
1k views

DNA pairs (adenine-thymine, guanine-cytosine) [closed]

Well I was wondering why adenine pairs with thymine and cytosine pairs with guanine. From those pictures: Thymine has the lowest acidity and adenine has the biggest acidity. So it is logical that ...
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1answer
108 views

Is sugar in mead different from “regular sugar”?

My understanding of the process of making mead is that you combine honey, yeast and water in an anaerobic environment. The yeast-bacteria ferments the sugar in the honey and produces ethanol (among ...
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1answer
586 views

what is the structure of bamboo kun?

There are claims that the bamboo fiber has inherent antibacterial properties due to "bamboo kun". However I could not find anywhere what is the chemical composition of this "bamboo kun" and also no ...
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52 views

Increasing concentration of acetylcholine via SPE

I am trying to increase the final yield of acetylcholine (ACh) in my biofluid samples. I need to get the yield high enough for high confidence annotation of ACh (currently all I can really say is that ...
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100 views

What does the formula (CH2O)106(NH3)16H3PO4 represent?

The molecular formula $\ce{(CH2O)106(NH3)16H3PO4}$ appears in the wikipedia entry for "anoxic bodies of water". A quick search suggests that it represents the product of photosynthesis, or the ...
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0answers
18 views

Modification of Janus nanoparticles [closed]

I would like to synthesis gold/polyacrylic acid (PAA) Janus nanoparticles in solution. Any ideas how I can functionalize gold with a photosensitizer and PAA with an antibody so that there would be no ...
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2answers
167 views

Why do chiral biological molecules only exist as one enantiomer? Does it have any advantage?

Why is it that chiral biological molecules are enantiomerically pure? The other enantiomer would have the same reactivity, and the only difference is their angle of rotation of plane polarized light. ...
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1answer
208 views

What are glues/adhesives for cardboard boxes/crates made of?

Open cardboard boxes/crates, often for foodstuffs, are often glued to hold their shape. What is the glue/adhesive made of? I ask to know if it is biodegradable, such that it is suitable for ...
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1answer
63 views

Can air conditioning cause urine smell?

On rainy days there is a strong urin smell on trains in Tokyo. I suspect this smell comes from ammonia. On Wikipedia I read: Ammonia and ammonium salts are also found in small quantities in ...
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1answer
59 views

How to determine toxicity of a substance? [closed]

I often read description of various compounds or elements as being poisonous. Now I know that through experience we have discovered the toxicity of various substances like lead, chlorine or phosgene ...
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29 views

Why do foraminifera use less magnesium in their shells when the water is cold?

When scientists study ancient seabed cores, they say they can judge the temperature of the water in the past by analyzing the magnesium to calcium ratio in foraminifera shells (both in the form of ...
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1answer
938 views

How are glycosidic linkages formed?

Consider glycosidic linkages in disaccharides. I know a condensation reaction occurs, with the loss of water. But which OH is lost? The O in the linkage belongs to which monosaccharide? Example: ...
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23 views

Purifying cysteine containing peptides

I would like to purify my peptide having cysteine residue by using HPLC. It is known that thiol containing peptides undergo oxidation and form disulfide linkages. In order to prevent it I used proper ...
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1answer
241 views

Why is molybdenum that important in inorganic synthesis as well as biosynthesis of ammonia?

We know that Mo (Molybdenum ) is used as a catalyst for Haber's process, during synthesis of Ammonia from Nitrogen. Again, in biological systems, Nitrogen fixation (ALSO forming Ammonia from Nitrogen)...
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2answers
52 views

What provides the energy allowing membrane proteins to facilitate diffusion across the membrane?

We know that facilitated diffusion requires no energy. But the transport proteins, when bind to a molecule from ECF (extra-cellular face) , the proteins rotate and deliver the molecule into ICF (...
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3answers
520 views

How can I prepare a PBS (Phosphate Buffer Solution)? pH=7.4 [closed]

Phosphate-buffered saline (abbreviated PBS) is a buffer solution commonly used in biological research. It is a water-based salt solution containing disodium hydrogen phosphate, sodium chloride and, in ...
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0answers
59 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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2answers
715 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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64 views

Oil + UV radiation = cholecalciferol?

According to a web site about health (Antranik): The oil that naturally comes from our skin is a type of cholesterol. Whenever we stand under direct sunlight, the ultraviolet rays react with ...
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1answer
5k views

Is there any difference between isotonic and isosmotic solution?

Is there any difference between isotonic and isosmotic solution? Can we say isotonic solution do not show osmosis because they have same osmotic pressure?