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7

This question really belongs at Chemistry.SE, but I'll give you a quick answer. A substance is soluble in water when its solid form (such as a sugar cube) completely dissolves in water to become a sugar solution. The sugar molecules themselves are unaffected, essentially - instead of all being bound to one another in a crystal, they are now floating around ...


7

It's the same stuff that makes up most sea shells, calcium carbonate, $CaCO_3$. Incidentally, this explains why egg shells dissolve in vinegar (acetic acid which, since it is an acid, provides the Hydrogen ions in the reaction below): $CaCO_3+ 2H^+ -> Ca^{2+} + H_2O +CO_2$ This simple reaction (which is what would happen in your stomach as well) ...


6

According to the abstract from this paper, the intragastric LD50 of $\Delta^9THC$ (tetrahydrocannabinol) in sesame oil using Fischer rats was 1270 mg/kg. Assuming rats and humans are identical (they're not), for an average-sized adult human weighing 70 kg (~155 lb.), the median lethal dose would be 88.9 grams, or about 3.1 oz. Keep in mind that's 3.1 oz. of ...


6

If they perform the exact same function, they can be considered the same functionally. Hemoglobin in most humans is the same, down to the amino acid sequence; the hemoglobin in sickle cell anemia, Hemoglobin C, Hemoglobin SC, thalassemia, and others are all different by at least one amino acid, yet they are all hemoglobins, and all do the same job: they ...


6

Human and mouse titin are orthologs, and can be confirmed through an NCBI query for TTN. Orthologous proteins are not the same, per se. They retain the same function, and basically result from speciation: the common ancestral gene got divided between two species. However, the sequence may potentially differ because obviously the species have diverged. ...


6

The smell of dry erase markers come from the chemicals ethanol, butanol and isopropyl alcohol. Like all chemicals inhaled through the nose, they bind to the Receptor neurons in the located in the back of the nose. The neurons interpret the chemicals using a 'lock-and-key' model but the specific way its coded and perceived in humans is still being researched ...


5

(1) Chain Length Will definitely affect melting point, as this website explains pretty well: "Melting point principle: as the molecular weight increases, the melting point increases." (2) Number of Methylene groups. This is another way of describing unsaturated from saturated fats. The more saturated a fat is, the straighter it is. Methylene ...


5

Short answer Assuming you wish to have a common name for both of these (widely differing!) pathways I basically agree with @Chris, and I would go for general terminology, namely metabolic pathways. Background The pentose-phosphate pathway is neither anabolic nor catabolic so those terms won't do. The pentose-phosphate pathway is, however, closely linked to ...


4

chemicalize.org is a good utility for predicting many molecular properties such as pKa, pI and charge. The Human Metabolome Database uses the same underlying software but tabulates some of the data (eg charge is explicitly stated). Acetyl-CoA, for example, has a pI of 1.32 and charge of -4 at pH=7.4. Your second link is to a portion of an enzyme (a ...


4

The first compound you mention is acetyl-co-enzyme A (acetyl-CoA) (first picture, left panel). The acetyl group is uncharged, but the co-enzyme A (CoA) group (Fig. 1, right panel) does carry charge through its phosphate groups. In normal physiologic environments these phosphate groups will donate one or more protons, leaving the molecule negatively charged, ...


4

Welcome to Biology.SE! Your question has nothing to do with evolutionary biology Evolutionary Theory does not explain the origin of life just like the Theory of Gravity does not explain the diffraction of light! In other words, explaining the origin of life is not within the scope of evolutionary biology. You should edit your title. But still, your ...


4

Okay, he's not wrong, technically speaking. Practically speaking never ever fertilize your plants with ammonia. The ammonia you spilled will be converted into nitrates eventually, so it's not like you spilled lead into your garden. On the other hand the populations of nitrifying bacteria take a fairly long time to adapt to a bounty like "a bunch" of ...


3

The Jaccard index is a measure of similarity between two sets. Take a look at the Wikipedia article here. It is very easy to compute: The Jaccard similarity coefficient for sets X and Y is defined as: J(X,Y) = |intersection(X,Y)| / |union(X,Y)| Where | | indicates the size (number of elements) of the set. Imagine you have two sets X and Y defined as ...


3

The minus sign in parentheses here indicates the optical rotation, (+) means the molecule rotates linear polarized light clockwise, (-) means it rotates counterclockwise. Typically you would also write exactly which stereoisomer is meant (R or S), which is generally the more useful information. The following are all valid names for the natural stereoisomer ...


3

The constitution of the biogas depends greatly on its source and the fermenting microbe. But in general, it does contain hydrogen about 0-1%. Even if it did contain large amounts, the mixture would be inflammable, but it would not burst into flames without any external igniter, which could be any small fluctuation of heat if the mixture is too unstable. But ...


2

I am not so familiar with enzymatic kits for quantifying glutamine, but most enzyme-based analysis kits come with a number of fairly strong assumptions on the enzymology involved, and in my experience they are difficult to use reliably. Commercial kits are hopeless to troubleshoot since their components are not disclosed --- you don't know what you're ...


2

As the concentration of sugars in the sap increases, so does viscosity. At high viscosity, the sap will not flow at a sufficient rate to provide nourishment to the different plant tissues. In addition, there are limitations to concentrating the solutes in the sap. As the sap becomes more concentrated, the plant would be working against a osmotic gradient to ...


2

If your looking at transcription then your talking about RNA POLYMERASE. And there are many variants. Here's a good Nature paper that discusses temperature and RNA Pol http://www.nature.com/ncomms/journal/v1/n6/full/ncomms1076.html And another: http://www.ncbi.nlm.nih.gov/m/pubmed/12729734/ I couldn't get full access to this JBC paper but I think the ...


1

This paper describes dewaxing of sunflower seeds using various solvents. As you have already shown for yourself, using hydrophilic substances such as bleach and acids do not work well in removing the waxes. Waxes are highly hydrophobic substances, and must be removed with either hydrophobic solvents (much like washing away acids with water at the emergency ...


1

The tautomers are rare but they can form and it is suggested that tautomerization can lead to mutations because of non-cognate base pairing. Khuu & Ho (2009), have inferred the presence of adenine and thymine tautomers from the crystal structure of an in-vitro assembled holliday junction. They infer that imino-Adenine base pairs with amino-cytosine ...


1

The synthesis of N-acetylglutamate is mediated by the enzyme N-acetylglutamate synthase. This enzyme has L-glutamate as its substrate and uses acetyl-coenzyme A as a co-enzyme acetyl donor. Acetylcoenzyme A (Acetyl-CoA) is generally abbreviated in structural formulas, because it is a relatively complex molecule. The only thing of relevance is the acetyl ...


1

As far as I can tell, enterochelin esterase (Fes) utilizes an Alpha/Beta hydrolase fold to catalyze it's reactions, which means there's a triad of catalytic amino acid side chains. Where Fes differs from other proteins in the pathway is an amino terminal lid domain which confers specificity to the substrates of Fes ((1) dictates this forms a deep pocket in ...


1

Considering the three basic biomolecules used by the body are carbohydrates, lipids, and proteins, you would need to consume these three molecules only. Now we can choose three substances. Glucose, one of the most basic carbohydrates, is needed for ATP production, so that would be a food choice there. Any oil or butter will provide lipids. Protein comes ...


1

Sigma gives a solubility of 200 microMole in water containing 2% ethanol. They state: Forskolin is soluble in water (with 2% ethanol) up to 0.2 mM by first dissolving in ethanol at 5 mg/mL and doing subsequent dilutions with water. The datasheet can be found here.


1

This is only an partial answer, as I do not have the time now to look for other references. In the chapter about milk, Harold McGee's beautiful book "On Food & Cooking" says (pg. 21 of the 2004 edition, bold is mine): Flavors from cooking Low-temperature pasteurization slightly modifies milk flavor by driving off some of the more delicate aromas, ...


1

The auto ignition temperature of a combustible mixture of hydrogen in air is 500 degrees C source - Wikipedia. It will not spontaneously ignite, some part of it must first reach that temperature through a spark, flame, or other heat source. Once it ignites, the methane of course will burn too.


1

Doxycyline inhibits iNOS and TNF-alpha expression. It also influences secretion of IL-1beta, IL-8, and TNF-alpha, as well as other inflammatory cytokines. [These are results collected from multiple systems.] For appropriate references, see: Leite et al (2011). Anti-inflammatory properties of Doxycycline and Minocycline in experimental models: an in vivo ...



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