33 votes

Would fewer cows mean less methane emission?

Couple of thoughts: (The OP's article is a low quality source of info with either an interview taken out of context or an inappropriately vague or under-informed interviewee. Reasons why will become ...
theforestecologist's user avatar
8 votes

Why is ammonia converted to urea rather than secreted in the urine?

The comment of the poster to my request for clarification cites “The formation of ammonia itself requires… large quantities of water to dilute it out of a biological system” I conclude that he assumes ...
David's user avatar
  • 25.7k
7 votes
Accepted

What is a lethal dose of THC?

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'...
MattDMo's user avatar
  • 15.3k
6 votes
Accepted

What is the minimum number of chemical elements required for life on earth? Does it vary between kingdoms?

If we change the question to "what is the minimum number of elements common to every form of life?", my lists would be as follows. (I am not considering either viruses or prions to be 'alive'...
user338907's user avatar
  • 4,723
6 votes

Why does the luminal test need hydrogen peroxide?

wouldn't there already be oxygen present within the blood itself or from the environment that would react with the luminol itself? I'd say that's the exact reason why peroxide is added. Without ...
X Zhang's user avatar
  • 354
6 votes
Accepted

1% water solution of deoxycholic acid. How is it prepared?

According to the sigma document you referenced (emphasis added by me): "The free acid is soluble at 0.24 g/L in water at 15ºC, while the sodium salt is soluble at >333 g/L in water at 15ºC. ...
MikeyC's user avatar
  • 4,714
6 votes
Accepted

Why do we need to amplify DNA sequences?

This is a question I also remember wondering about when I was younger in school. Now as a professional it's way too obvious to even explain. But i think it's an important and common question, which ...
S Pr's user avatar
  • 6,222
5 votes
Accepted

Is studying chemical and physical properties of chemical substances that make up organisms really a task of molecular biology?

If you look at the Google ngram for the term ‘Molecular Biology’ you will see that it first appears just before 1960, and it is relevant that the Journal of Molecular Biology was founded in 1959. It ...
David's user avatar
  • 25.7k
5 votes

Is the formula of cyclic adenosine monophosphate (cAMP) $\ce{C_{10}H_{11}N_{5}O_{6}P}$ or $\ce{C_{10}H_{12}N_{5}O_{6}P}$? Does it matter?

Without links to, or presentation of, examples of the two formulae it is not possible to be sure that the following explains the particular experience of the poster, but nevertheless I provide it as ...
David's user avatar
  • 25.7k
4 votes
Accepted

Why is there no wavelength change in the hyperchromic shift in DNA?

We are dealing here with the quantities differing by (at least) two orders of magnitude: energy corresponding to 260nm radiation is about 110 kcal/mol (here is a converter) stacking energies of DNA ...
Roger V.'s user avatar
  • 3,852
4 votes

Biochemistry - Plastic eating microbes at home

Although you should be able to find bacteria that can grow on plastic, I think your criteria of 'not difficult to find' might be a challenging one to meet. Poly(ethylene terephthalate) (PET) is a ...
Noah Sprent's user avatar
4 votes
Accepted

Text Book Recommendation: Cell & Molecular Biology + Organic Chemistry

Given your requirements I would go for the Alberts for molecular cell biology. For organic chemistry, in my opinion, there is no better book then the Clayden. It is targeted at OC students but I - as ...
AlexDeLarge's user avatar
  • 2,868
3 votes

Why does decomposing matter emit a bad smell?

Since this question has no answer, I thought of taking a stab at it. Why does decomposing matter emit a bad smell? Due to cadaverine and putrescine. More information here: What produces the strong ...
Nilay Ghosh's user avatar
  • 1,214
3 votes

Is DEET (as in the mosquito repellent), a substituted phenethylamine?

While I feel like this might be a better question for the chemistry SE, lets take a look at the molecular structures: The basic structure of a phenethylamine (left, modified from here) versus DEET (...
Nicolai's user avatar
  • 4,391
3 votes
Accepted

Glycogen vs cellulose-curvature of glycogen molecule?

Interesting question. Here, the question actually comes down to how the bond actually looks vs how we depict the bond. In detail, see this image of maltose from here: Pay attention to the geometry of ...
another 'Homo sapien''s user avatar
3 votes

Can the dietary fibres as chemical compounds be regarded as polymers?

Dietary fibers are the indigestible portion of food derived from plants. Most of these are indeed polymers of sugars (that is, a chain of repeated basic unit of carbohydrate), for example cellulose, ...
Eliane B.'s user avatar
  • 1,145
3 votes
Accepted

Does baking soda interfere with digestion when cooked into food?

The relationship between acid and bicarbonate is that 1 H+ neutralizes 1 bicarbonate (HCO3) molecule as represented in the following equation: HCl + NaHCO3 --> NaCl + H2CO3 So assuming that the ...
bob1's user avatar
  • 12.1k
3 votes
Accepted

Are DNA molecules negatively charged at low pH values?

You are right. At a ph<5 which is where the PI of DNA breaks down, the phosphate group will bind protons, while the nitrogenous bases will become positively charged owing to the acidic environment.
Shivansh Kanojia's user avatar
2 votes

Do right-handed helices bind to right-handed helices, and vice versa?

My understanding is that protein and DNA helices show the handedness that they do due largely to the intrinsic chirality of their components. Note that in natural biomolecules L-amino acids and D-...
Maximilian Press's user avatar
2 votes
Accepted

How is it known that there are only three macronutrients: proteins carbohydrates and lipids?

Summary The question is based on the misconception that the term “macronutrient” originated as a scientific definition, to which entities satisfying this definition were assigned. In fact it was a ...
David's user avatar
  • 25.7k
2 votes

Does mechanotransduction of cells play a role in the biocompatibility of titanium?

First off, AOZ has a wonderful page about titanium alloy uses in medical applications you should read and that most of my info is coming from: Suitability of Titanium for Implant Purposes I think ...
RyFa's user avatar
  • 56
2 votes
Accepted

Can emulsion test be used to detect phospholipids?

Yes, the test will still work. And you are correct about the phospholipid's process of forming 'circles' in water. The reason the test still works is because alcohol increases the permeability of the ...
Reece's user avatar
  • 213
2 votes

Tryptophan side-chain structure, how should it be orientated?

Good question, this regards rotamers! Basically, the side chain of amino acids can rotate as shown in the figure below for glutamate (Glu; E). The various option for side-chain rotation is called ...
CuriousTree's user avatar
1 vote
Accepted

Quantification of various amino acids from bacteria?

A good approach could be to use GC-MS to identify cytosolic metabolites. When focussing on cytosolic amino acids, it might be useful to precipitate the proteins in a purification step and continue ...
Lobostrous's user avatar
1 vote

Is there anyway from which we can measure the viscosity of honey using a refractometer?

Theoretically, if refractive index and viscosity are both simply functions of moisture content, you should be able to use one to approximate the other using an empirical standard curve. However, based ...
MikeyC's user avatar
  • 4,714
1 vote

Glycosidic bonds

In a cyclic molecule of glucose, C1 is the result of the aldehide group linked to C5. This makes C1 a reducing carbon that can share electrons. This is why C1 must always take part in a glycosidic ...
SoyBiotec's user avatar
1 vote

How do alcohols and aldehydes destroy the plasma membranes of bacteria?

Alcohols are dehydrating - they remove water from the cell. And since cells need water to survive, this is lethal to bacteria. However, in order to work effectively, an alcohol needs the proper amount ...
ndusek's user avatar
  • 76
1 vote

What are some uses of oxidative/reductive power inside cells?

This topic is quite broad, excluding energetic metabolism, there are still many reactions that use redox equivalents, whether NADH, NADPH, or FADH. Here are some paradigmatic illustrations. ...
Eliane B.'s user avatar
  • 1,145
1 vote

Wax layer destruction from seed coats

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 ...
March Ho's user avatar
  • 9,452

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