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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Can the sulphur content of biological material be reliably calculated from fat, fibre and protein contents (Weender Analysis)?

An often-used analysis of feedstocks for lifestocks is the Weender analysis, which basically divides the volatile solid content into fats, fibre and protein, as well as N-free matter. I found no ...
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4answers
20k views

Death because of distilled water consumption

One of my friends said that I would die if I drank distilled water (we were using it in a chemistry experiment) I gave it a go and surprisingly did not die. I did a bit of Googling and found this ...
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71 views

What are the ways to test for protein in the canine urine?

I know that one way is to use the reagent sticks and the refractometer, but this is inaccurate. Is protein distinguishable when using a microscope? Is it time sensitive(i.e. have to test it right ...
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71 views

Where do the electrons and protons formed from biological reactions go?

In a reaction like disulphide bond formation protons and electrons are released. These particles are presumably damaging in high levels. What systems are in place to prevent a build up of electrons ...
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27 views

recombinant peptide MHC complex

What is recombinant peptide-MHC complex??? Recombinant DNA means "to bring together genetic material from multiple sources, creating sequences that would not otherwise be found in biological ...
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1answer
43 views

How can I determine the purity of cells isolated from rat brains if I cannot use FACS, Immunohistochemistry or SEM anaysis?

Please help. I know how to isolate the different cells (astrocytes, other glial cells, neurons and synaptosomes) from brain tissue using a Ficoll-based separation but how do I determine the purity of ...
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19 views

Immunomic Microarray

"One can measure two or more signals simultaneously determined by a single feature, i.e., epitope in immunomic microarray DNA microarrays measure one response value for each gene per sample; that ...
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56 views

What is the physiological difference between cortisone and cortisol?

There is only hydrogen bond different. Cortisol is synthesized by our body, while cortisone is given to the patient. Why you cannot give cortisol directly to the patient? I think the reason is ...
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46 views

What is hTAP?? Please help

Could not find a single article regarding this. What is hTAP? Tap is Transfer associated protein, that I know, but what is hTAP??(I have not studied biology since last 8 years and now I am going ...
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23 views

epitope prediction/ mapping

B-CELL EPITOPE PREDICTION Regarding this article: "Such a molecule can be synthesized or, in case of a protein, its gene can be cloned into an expression vector."----- is a particular line in ...
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25 views

How does Temperature influences the rate of protein turnover? [duplicate]

Question How (quantitatively speaking) does temperature influences rate of turnover of transcription factors? Which protein? As I am not looking for any accurate number I am talking about an ...
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48 views

Correlating beta-lactamase expression to absorbance

When penicillin-resistant bacteria are grown in liquid culture media, β-lactamase is secreted into the medium. The supernatant of such a medium can be assayed for β-lactamase activity. ...
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51 views

Can diseases be transmitted wirelessly? [closed]

According to the recent research about Electromagnetic Signals from Bacterial DNA (A. Widom, J. Swain, Y. N. Srivastava, S. Sivasubramanian) it seems there is a possibility of a "wireless" version of ...
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23 views

What is Colloidal biology and does it have any scientific background?

There is the following bulletin published for the History of Chemistry Vol. 32: 105-118 in 2007: “MOLECULAR” VERSUS “COLLOIDAL”: CONTROVERSIES IN BIOLOGY AND BIOCHEMISTRY, 1900–1940* written by PhD ...
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13 views

transfection of expression library made from cDNA into cells expressing the desired MHC haplotypes

http://www.sciencedirect.com/science/article/pii/S0167569997800205 If anybody has access to this paper, can you please explain me the process to find TAA based on transfection of expression library ...
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1answer
19 views

Meta-analysis of fruits in blocking Cytochrome family

My professor says that some drugs cannot be used with grapefruit. I am trying to search a list of cytochromes and their effect to block members in the cytochrome family. Some in Cyt P450. What is ...
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394 views

What is an irreversible reaction?

There are reactions with large Delta G negative values. Why these reactions are irreversible? As in: out of 10 steps of Glycolysis, 3 are irreversible steps. I need an explanation for why they are ...
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36 views

How to calculate when the velocity declines in an Enzyme Kinetics Problem [closed]

If you have an E,S pair that has KM and Vmax values of 2 mM and 1 mM/sec/μM enzyme and you start the reaction with 10 mM [S] and 1 μM [E], approximately how long will the E,S system stay in the ...
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37 views

Affinity isolated peptide

What is affinity isolated peptides??(I have not studied biology since last 8 years and now I am going through it because I need it for my research. So if someone can describe it in simple language it ...
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2answers
62 views

Manufacturing of Bio Molecules [closed]

Can we Manufacture bio molecules say e.g. the simplest Sugar, C12,H22,O11 the way we do with any other mechanical component. So, we know all about the Structure and arrangement of Atoms in Sugar - so ...
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24 views

MHC restricted peptide

What is an MHC restricted peptide? "MHC-restricted antigen recognition, or MHC restriction, refers to the fact that a given T cell will recognize a peptide antigen only when it is bound to a host ...
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2answers
21 views

Question about flavodiiron protein

I came across an article about flavodiiron proteins that are responsible for reducing ${\rm O}_2$ to ${\rm H}_2{\rm O}$ thereby protecting the anaerobic prokaryotes and some eukaryotes from oxidative ...
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153 views

Appropriate Buffer for electerophoresis of DNA & Protein TBE or TAE?

Which buffer is best for DNA Electrophoresis and which is best for Protein to be have a sharp bond? Considering a higher electrical conductivity compared to TAE & TBE and the generation of less ...
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107 views

Integration of several environmental signals

I am looking for examples of different functions that are good fit to how signals are computed in order to respond to the environment. Let's make my question more copmrehensible with an example... ...
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1answer
57 views

Influence of temperature on protein binding and decay rates

For computer modeling purposes, I am looking for some referenced quantitative measurements of the effect(s) of temperature on the dynamic of biochemical reactions. Question In particular, my ...
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44 views

Why is lead dangerous? [closed]

Lead is known to be bad for your health for a long time, but I can't find a explanation why is it so. In school they teach that heavy metals are poisonous, and they are trapped inside our bodies. I ...
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49 views

How is the rate of transcription influenced by temperature?

How is the rate of transcription influenced by temperature? More precisely, I am looking for an article who quantitatively measured the rate of transcription of an "average gene" and show how this ...
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984 views

Why are there no organisms with metal body parts, like weapons, bones, and armour? (Or are there?)

Reading this question, Why are there no wheeled animals?, I wondered why no organisms seem to make use of the tensile and other strengths of metal, as we do in metal tools and constructions. I am ...
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63 views

Influence of temperature on transcription, protein binding and decay rates

I am the kind of biologist who doesn't know much about molecular genetics and about the dynamic of biochemical reactions. Question My question concerns the influence of temperature on the dynamic of ...
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1answer
140 views

Why do we absorb vitamins better from whole foods than from pills?

We can't rely on pills to provide us our nutrients because we don't absorb the nutrients from the pills as effectively. Presumably this is because pills are lacking components that are required for ...
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122 views

What is most simple eukaryotic genome?

Expressed in number of Base Pairs or Bytes, about how large is the simplest eukaryotic genome? How much of this is 'junk-DNA' (non-coding)?
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79 views

What causes skewed ladder bands on an agarose gel?

I frequently ran into an issue where the bands of my ladder become skewed. What causes this? Here's an example: 0.7% agarose gel, 100V, 60 minutes. Same problem occurs with 1%. I loaded 10 ul of a 20 ...
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1answer
47 views

What is the expected effect of pH on the activity of a fungal pectinase?

I am working on an enzyme assay for a fungal pectinase.I assayed the enzyme in different buffers from pH 1-12.5 However,the enzyme has good activities starting from pH1-10.5. Is it possible to have ...
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279 views

Are there dangers to Teflon and aluminium cookware?

I've been reading some articles on the internet about dangers of Teflon and aluminium to the body. My family say I'm just exaggerating the situation, and maybe I am, though I'm not sure because not ...
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How to determine whether the energy of a stem-loop fold is significant or not?

If I have a predicted RNA stem-loop of energy -0.30 kcal/mol, and another of -4.9 kcal/mol, how do I tell whether such a structure is a significantly stable structure or not? Our two competing ...
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1answer
102 views

Enzyme Assay, absorbance change to concentration change

I have a few issues with this question. An enzyme assay is performed and the kinetic data graphed. The y-intercept of a Lineweaver-Burk plot is 0.6 min/ΔA. The substrate being assayed has a molar ...
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1answer
41 views

How do you express and detect GLP-1 receptors?

I am currently working with a peptide which is an analogue for glp-1, but during invitro studies am not able to detect for the presence of GLP1- receptors. The cell line used is Min-6. How do I detect ...
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37 views

Concentration dependent cellular processes

Are there any famous biological processes that depend strongly on a chemical concentration reaching a particular value, like some sort of switch? E.g. if concentration of chemical x reaches ...
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130 views

which signalling pathway is involved in cancer?

Columnar epithelial cells from the colonic mucosa are studied to identify abnormalities in cell signaling pathways. Abnormal epithelial cells from colonic adenocarcinoma are shown to have a mutation ...
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What is the biding site code recognized by the parts of the spliceosome

Another question about another Youtube video. At 0:50, the splicing process begins to remove the non-coding section of the DNA (intron), so the different parts of the spliceosome attach to the borders ...
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Why is oxygen needed for the electron transfer phosphorylation?

I understand that oxygen is the acceptor of electrons and hydrogen ions during the electron transfer phosphorylation, the last step off the ATP-producing aerobic respiration. But why? Aren't there ...
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What is an effective method for putting on blue rubber butyl stoppers?

They look like this. We have to do a lot of gas sampling and these are really difficult to assemble. I've been scouring the internet for advice but there are none. Do you have experience with ...
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4answers
172 views

Specificity of Protein Kinases in Signaling Pathways..?

In most of the signaling pathways the activated receptor when activates Protein Kinase through the action of secondary messenger, then these protein kinases almost always phosphorylate on the specific ...
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1answer
43 views

Why do oncogenes show genetic dominance?

As we know that tumor suppressor gene causes cancer only when both the alleles are recessive in nature.But in case of oncogenes if only one allele is dominant it can cause cancer.Why in case of ...
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174 views

Effect of steroid hormone on specific cells?

As steroid hormones can pass through the plasma membrane by simple diffusion because they are lipid derived hormones, it means that they are capable of passing through every cell of our body, BUT why ...
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261 views

What can cause the bloating in high protein diet of Whey proteins?

I am thinking what can cause the swelling of gastrointestinal system i.e. bloating after high protein diet of Whey proteins. Liver does breaks those proteins to branched chain amino acids (BCAA), ...
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39 views

Mechanism of DNA gyrase inhibitor

Why DNA gyrase inhibitor, such as Nalidixic acid and Norfloxacin, do not stop gyrase from cutting DNA helix but only prevent them from decatenation replicating DNA?
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54 views

In what forms do plants and animals excrete sulfur?

Sulfur is part of the amino acids cystein and methionin, plants take up sulfur in the form of $H_2S$. These organisms will also need a way to get rid of excess sulfur, how? In what compounds? Judging ...
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72 views

Bohr effect in respiration

Would I be correct in saying that the Bohr effect is ONLY related to the concentration of [H+] in the tissues. Obviously the concentration of carbon-dioxide can contribute to this concentration by ...
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229 views

Equation for accurate prediction of PCR yield

It is a cliche of freshman biology labs to point out that "every cycle of PCR doubles the DNA, so the yield will be $2^{cycles}$ times the template amount". However, if this were true, 1 ng of ...