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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Standard solution for alkaloid separation in HPLC [on hold]

In the middle of my college project, I am in need of performing alkaloids separation from Aloe-vera using HPLC. Can anyone help me by mentioning the standard solution to be used for this separation?
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1answer
34 views

Why sigmoid curves appear in quantitative analysis of many biological phenomena? [on hold]

I know two examples: 1-The binding of hemoglobin to oxygen (binding of oxygen to one site of hemoglobin induces conformational changes which increase the affinity of the other sites for oxygen - the ...
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2answers
26 views

Biochemical coupling between two enzymatic reactions - Enzymes physically associated?

I am wondering what the exact definition of biochemical coupling between two enzymatic reactions is. I know that these two enzymatic reactions have to share the same intermediate(s) one is ...
3
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1answer
19 views

To which negatively charged components of the cell envelopes do the crystal violet complexes bind in gram staining?

The gram positive have negative components in the peptidoglycan layer in the form of teichoic acid phosphodiester bonds, and the gram negative have negative components in their outer membrane in the ...
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1answer
57 views

Why does high pH result in the denaturation of DNA?

In the Southern blot method, for example, a solution of NaOH is used to denature the DNA in the sample. I find this counterintuitive since I expected that $\text{Na}^+$ cations would neutralize the ...
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1answer
33 views

Examples of how the presence or absence 2'-hydroxyl groups influence physicochemical properties of DNA and RNA

I know, for instance, that RNA is much more succetible to alkaline hydrolysis than DNA and this difference is determined by the presence of 2'-hydroxyl group in ribose. I have also heard that "DNA is ...
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0answers
12 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 ...
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30 views

Do chemical differences in the male and female body influence differences in brain development? [closed]

I asked the question Have different mental strengths evolved in men and women?, being curious about differences in the mental strengths of men and women, but after reading that men and women have very ...
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33 views

If you are God, how would you create an efficient priming reaction? [closed]

Imagine that you are “natural selection” (or God if you prefer) and you can reconstitute replication changing the concentrations or the properties (higher/lower activity; reactivity; etc.) of the ...
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4answers
73 views

Does the necessary Carbon Dioxide need to be in the atmosphere for mammals?

In the answers to this question, we've learnt that carbon dioxide is necessary for mammalian life. But, is it necessary in the atmosphere/to breathe it in? Or does the act of respiration give a ...
4
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0answers
38 views

What is the difference between organelle membranes?

Cells and organelles are contained in lipid bilayers. I'm particularly interested in eukaryotic organelle bilayers and the biophysicochemical differences between them. Many papers assume a ...
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2answers
30 views

Determination of a chemical compound in a non-homogeneous sample

This is a more generalized question of my other question here. I want to know if it is possible to determine a chemical compound in a non-homogeneous sample. I am asking this because we are aiming ...
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2answers
37 views

what does Pro→Glu substitution mean?

Considering the paper: A single amino acid in E-cadherin responsible for host specificity towards the human pathogen Listeria monocytogenes in the abstract portion, what does Pro→Glu mean? Does it ...
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4answers
33 views

Enzymatic error rate

I am aware that each enzyme generate a certain amount of misproducts. This is well documented, for example, for the DNA polymerase. I am interested in enzyme involved in biochemical processes, so for ...
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1answer
48 views

Which will produce more oxygen? Less number of (larger) trees or more number of (smaller) plants?

In a given area A, we have two choices - (i) we can plant maximum number of trees (which are larger in size) possible in A, say m OR (ii) we can plant maximum number of plants (which are smaller in ...
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27 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 ...
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1answer
917 views

What is the most condensed form of (stored) energy used in biology?

When considering how organisms store energy for later use, I was wondering what substance known in Biology is best for compacting the most energy in the smallest space(volume-wise). With my (limited) ...
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0answers
32 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 ...
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0answers
50 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 .
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2answers
64 views

What is a triglyceride?

I'm confused on what a triglyceride is, from what my text book it says its a type of gylercide, then from a website it said Glycerides can be subdivided into two categories. The first group, the ...
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0answers
27 views

Is there a biological environment that we can we assume glutamate exists as glutamic acid?

In the body we almost always assume that glutamate exists as glutamate rather than glutamic acid. It is so commonly glutamate yet glutamic acid and glutamate share the abbreviations of Glu and E. From ...
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2answers
43 views

How to preserve leaves between sampling (collection) and analysis?

Suppose I spend a day in a forest, collecting different kinds of leaves, which I would like to analyze under a compound microscope. Now, obviously, measures should be taken to preserve the leaves some ...
3
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1answer
31 views

Is using Hidden Markov Models to find homologues sensible in abstract, short sequences?

HMM alignment tools like hhpred excel at finding subtle homologues of folded proteins that simpler scoring techniques (such those used in BLAST algorithms) would miss. I am only looking at a small ...
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1answer
29 views

Why is the resting potential of a neuron so close to the equilibrium potential of K⁺?

I know this has something to do with the K+ leak channel. I just don't understand how. I know that 3 Na+ are pumped out for every 2 K+ pumped in. This makes the cell interior net negative. I know ...
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1answer
29 views

Are there U-rich transcriptional pause sites?

I've heard a statement in a talk that U-rich sequences cause transcriptional pausing. The intuitive explanation for this was that the UTP concentration is lower in the cell than the ATP concentration. ...
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23 views

Explanation of sequence motif diagram given in wikipedia [duplicate]

can someone please explain me this graph?? I did not get what information content is in this graph means. Does the size of the letter indicate that higher chance of that letter to be present in that ...
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22 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 ...
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17 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
15 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 ...
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1answer
24 views

Dehydration from caffeine, alcohol and other

Tea, Coffee, Beer, Coke etc… I wonder if the benefit from amount of fluid we get from them is bigger or smaller then the handicap of dehydration. In other words it is worth to drink them if we want ...
2
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1answer
45 views

Dehydration by a tea, coffee, beer etc

For the long time I am trying to find out if the following is truth: They say that some beverages dehydrates. I heard that about tea (sometimes green, sometimes black, sometimes both), coffee, beer ...
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2answers
40 views

Conversion of glucose to glycogen

Why is excess glucose, as a glycogen, stored in only a limited amount as compared to the lipid in our body? Why is mature glycogen arranged (polymerized) in 12 tiers polymer?
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17 views

What would happen to a body in an astronaut suit over time if floating free? [duplicate]

I'm not sure if this is best in Biology or Physics, but on Earth we decay to skeletons and then eventually to dust. What would happen in space in a space suit?
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1answer
64 views

How long does it take to form a peptide bond?

What is the time taken to form a peptide bond in vivo or in vitro? It isn't mentioned in my course on protein structures. I was just curious to find out if any time scale is known? Given that ...
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1answer
34 views

How much mass does a person lose in a day through breathing and perspiration?

Water and carbon are lost through perspiration and breathing. How much mass is lost in this way in a single day for a typical person?
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20 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, ...
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3answers
93 views

True or false & fill in the blanks

A ribosome is where amino acids are linked together by peptide bonds. A virus is NOT considered prokaryotic because it does not have a membrane. The nucleotide ATP is one of the most used energy ...
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1answer
48 views

Could we engineer humans to behave like insects? [closed]

First off, though complex, I'm assuming insects are at an earlier evolutionary stage than humans. That being said, could humans be genetically engineered to behave like insects? I'm not talking about ...
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1answer
33 views

Glycerol 3-phosphate nomenclature

Why is Glycerol 3-phosphate named in such way? Shouldn't it be named as Glycerol 1-phosphate by proper IUPAC- nomenclature?
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0answers
40 views

Why is ATP the main nucleoside triphosphate used to exchange energy? [duplicate]

Out of all of the nucleoside triphosphates what makes ATP the most used? Is it its structure? The amount of energy it contains? Why is GTP not used as much? What is the deal with the other nucleoside ...
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2answers
59 views

Why is water a polar molecule? [closed]

Also, what is the definition of polar in this case? (9th Grade) Does it have to do with the bonds it makes?
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1answer
43 views

Is it possible that a set of functionally related proteins in a pathway fulfill different functions?

Could it be that a given pathway of enzymes (or proteins in general) may fulfill different purposes in a cell by for shifting partners? Say protein A activates B, B activates C and C has a specific ...
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1answer
53 views

Why is leucine amino acid used the most in proteins and tryptophan the least?

The amino acid leucine, is used in proteins more than others. Leucine with 9.1 percent (its average in more than 1.150 different proteins) is used most and tryptophan with 1.4 percent is used less ...
5
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1answer
40 views

Are there ways to speed up the growth of plants?

I'm interested in what humans can do to speed up the rate of growth in a plant. I'm interested in both the context of home gardening and large-scale, institution-backed projects. Obviously, optimal ...
9
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1answer
214 views

Why doesn't HDL cause diseases like LDL?

LDL particles pose a risk for cardiovascular disease when they invade the endothelium and become oxidized, since the oxidized forms are more easily retained by the proteoglycans. A complex set of ...
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1answer
30 views

How is oxygen and carbon dioxide exchange mediated by hemoglobin? [closed]

Oxygen is transferred by hemoglobin from the lungs to tissues, while carbon dioxide is transferred by hemoglobin from tissues to lungs. How is this regulated bidirectional transfer mediated?
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1answer
34 views

What is the importance of urea in mass spectrometry?

What is the importance of urea in mass spectrometry? We use 8M urea to FASP our proteins prior to mass spectrometry. What is the significance of using 8M urea? and how does it affect the proteins?
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3answers
168 views

Formation of Life

Originally, life evolved from non-living matter. Why is life only generated from other life nowadays, and why doesn't it evolve from inanimate matter, like it did originally billions of years ago, ...
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1answer
19 views

What controls Fructose regulation in plants?

Sugars are found ubiquitously in plants and are regulated. For sucrose it's pretty straightforward - it's basically kept at a low ish level, and put into storage or other intermediate compounds. ...
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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 ...