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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To which negatively charged components of the cell envelopes do the CV+ 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 ...
6
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1answer
44 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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1answer
40 views

Why high pH favours denaturation of DNA?

In the southern blot method, for example, a solution of NaOH is used to denaturate the DNA on the sample. I find this counterintuitive since I expected that Na$^+$ cations would neutralize the ...
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4answers
72 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 ...
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0answers
12 views

What's the exactly definition of a cooperative process?

I know, for exemple, that the binding of oxygen to hemoglobin exibits a cooperative pattern, which reflects in a sigmoid curve, since the binding of one molecule increases the probability of new ...
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1answer
31 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
11 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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29 views

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

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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2answers
23 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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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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0answers
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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0answers
36 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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1answer
30 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
643 views

Can siRNA induce DNA methylation in mammalian cells?

Some years ago Hiroaki Kawasaki and Kazunari Taira published an article called "Induction of DNA methylation and gene silencing by short interfering RNAs in human cells" in Nature: In plants, ...
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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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0answers
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
2k views

What are the units of Q10 (temperature sensitivity)?

$Q_{10}$ is the increase in a rate (e.g. activity of an enzyme) observed with a 10° temperature increase. According to Wikipedia: ...
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1answer
914 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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2answers
433 views

Why do living organisms replicate itself or procreate

Why do living organisms spontaneously replicate itself or "procreate" (my understanding is that it does). From a uni-cellular and micro-organism point of view. Is there some sort of stimulant in the ...
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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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2answers
255 views

During famine, does the human body do anything to prioritize which organs receive nutrients?

When food is scarce, the body slows its metabolism. Are there any other systems or processes that encourage prioritization of organs?
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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
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 ...
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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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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
24 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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0answers
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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0answers
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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1answer
58 views

Enzyme Assay - pectinase

During assaying an enzyme at high temperature, the substrate (Pectin) is degraded by the high temperature rather than by enzyme, so, how can I minimize degradation of the substrate by the temperature? ...
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2answers
1k views

Diffusion of Hypotonic solution into solution with glucose and starch

Cell walls are selectively permeable to ions and organic molecules. Sometimes the selectivity is passive and a reflection of the physical laws governing diffusion. We can do simple experiments that ...
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0answers
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 ...
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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 ...
3
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1answer
62 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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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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0answers
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
66 views

Statistics on energy consumption breakdown per biological functions across organisms?

Are there any statistics available on how much energy organisms use for each biological functions (i.e. something similar to the line of "Bacteria spend X% of energy on information processing, Y% for ...
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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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3answers
92 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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0answers
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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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
70 views

Is there a known glucosepane cross-link breaker?

I read the following on wikipedia: There is, however, no agent known that can break down the most common AGE, glucosepane, which appears 10 to 1,000 times more common in human tissue than any ...
2
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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?
3
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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?
2
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0answers
34 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
37 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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1answer
211 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 ...