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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What chemical form of vitamin A is in chicken's egg yolk?

After doing some existing background research I am confused as to exactly what, in an unfertilised chicken egg's yolk, offers what we intake as 'Vitamin A' upon eating it. Plants typically produce ...
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39 views

Does vinegar neutralize the strongly-basic compounds in cement? [migrated]

I have heard that washing one's hands with vinegar is effective in neutralizing the strong bases in cement and is more effective than water. I want to know how cement burns, and what bases are ...
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3answers
86 views

More entropy: Atom or Macromolecule? [on hold]

A question that appeared on my last exam was : Which of the following has greater entropy A) An atom B) A macromolecule The question doesn't specify anything else(i.e. type/size of atom or ...
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80 views

Why doesn't honey spoil quickly? [duplicate]

Why is it that honey can last for decades and not spoil like other foods? Is there any chemical in honey which gives rise to this amazing feat?
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1answer
59 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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1answer
36 views

Mesoporous silica particles as anti cancer drug delivery method

If this question is a little off topic for Biology, I'm sorry. I've recently read a lot about mesoporous silica nanoparticles as a promising drug delivery method. The huge range of customizability of ...
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1answer
78 views

Question about Monofunctional glycosylases

I am learning about Base excision repair mechanism. I understand the main idea how glycosylases are working, but I am trying to understand this with much more details. I found a paper where they are ...
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1answer
49 views

How to recognize a conserved motifs of the protein

I would like ensure that my reasoning is correct. Assuming that I know the aminoacids sequence of the protein of interest. I can't say anything about the structure looking only at the aminoacids ...
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1answer
30 views

Significance of synthesis of D-glucose in plants..?

why plants can only synthesize D-glucose why not L-glucose along with D glucose. I know it very well that plants have only enzymes which can synthesize D-glucose but Why not they have enzymes which ...
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19 views

Formation of peptide bond..?

Proteins peptide bond is made by condensation process in which a molecule of water is released and according to this process it is not favorable in water systems than how peptide bond is formed by ...
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2answers
47 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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95 views

Effect of testosterone hormone on cell signalling and behaviour?

A steroid, testosterone was injected in female body which led to development of secondary sexual characters but these characters were not developed over night (Response was very slow). What could be ...
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219 views

Why does Hunger lead to the aggressive behavior?

I have observed that frequently when people are hungry; they tend to get angry more easily on pointless issues. Does this mean that our fight or flight response is more active when a person is hungry? ...
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138 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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2answers
88 views

Essential amino acid codons

Essential amino acids also have codons.Still they are needed by humans through diet?Will those codons do synthesize amino acids for some other purposes in humans or not?If so, what is the purpose?e.g? ...
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21 views

Is it possible to synthetically replicate the results of cryptobiosis? If so, how?

Okay if my question seems ridiculous I apologize because I have next to no knowledge of synthetic biology and what the field is capable of doing and it's methods and methodology. Take a organism ...
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24 views

Basic chemistry of the Shinoda test for flavonoids? [migrated]

In this test, four pieces of magnesium fillings (ribbon) are added to the ethanolic extract followed by a few drops of concentrated hydrochloric acid. A reddish colour indicates the presence of ...
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1answer
21 views

Primers on Dystonia

Where can I get a good biochemical overview of dystonia? I will be working in a research lab that focuses on dystonia and I would like to not be clueless.
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1answer
26 views

Is the sense for salt depending on the electrolyte level in our body?

I often noticed, after (heavy) physical activity like cycling, running, swimming or working an isotonic drink (to recover the electrolyte level) tastes less "salty" compared to when drinking it before ...
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1answer
38 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 ...
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37 views

How does one quantify T7 RNA polymerase transcription efficiency?

I am looking for a method which can help me calculate how many sequences one will get after transcription of 100-mer random sequences by T7 RNAP. The sequence pool has a known complexity and will be ...
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0answers
29 views

What causes the odor when a container is sealed with moisture inside?

I'm not sure if this is a biology or chemistry question since I don't know the cause of it (though I think it is bacteria or fungal related). I'm just wondering what creates that awful odor when a ...
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2answers
76 views

alpha tubulin molecular weight problem

Is there any academic reference that shows α-tubulin is around 50-55 kDa? The only thing I found is some data sheets from companies. I need the real reference.
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2answers
56 views

How does guanidium denature DNA?

Guanidium salts like (G-isothiocyanate) disrupt the hydrophobic interactions inside a protein or nucleic acid and denature it. What happens when hydrophobic interactions in DNA are broken? (I don't ...
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1answer
63 views

How do a particular arrangement of atoms become self aware? [closed]

At the simplest level, we're all just atoms, animals, plants and humans alike. But what I don't understand, is how a particular arrangement of atoms such as us can become self aware, and be able to ...
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49 views

Anaerobic respiration choice in E. coli

Under anaerobic conditions E. coli has two options to generate ATP: fermentation (substrate-level phosphorylation), and respiration (proton gradient, chemisomotic phosphorylation). Which is favored? ...
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2answers
154 views

How much vanilla will kill a person?

I received a gift that is a jug of Pure Mexican Vanilla. Having never dealt with large quantities of vanilla, it made me curious as to what would happen if a person had too much vanilla. I understand ...
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1answer
70 views

Drinkable liquids that dont contain water [closed]

Are there any drinkable liquids that don't contain water? By drinkable I mean it would not harm me by just drinking it, like water.
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247 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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1answer
28 views

Feedback affecting myocyte metabolism in humans

I understand that there are several reserves available to muscle that can be tapped for ATP, and that each reserve is being used to some degree at all times. Are these reaction rates purely due to ...
2
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1answer
35 views

What is inside IDL (intermediate density lipoproteïn)?

I am studying about the endogene lipidcycle in the human body and I know that VLDL (very low density lipoproteïn) is made in the liver and that it contains triglycerides and cholesterol from your food ...
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1answer
49 views

Fatty Acid Synthesis

I have a problem in my reasoning on the fatty acid synthesis in the human body. In the synthesis proces you have this dimere or dimeer or I don't know how you call it in English, and it excists out ...
2
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1answer
30 views

Trimming of tRNA precursors

From Molecular Biology of the Cell (4th edition) by Bruce Alberts et al. (Chp 6, Pg 338) : Both bacterial and eucaryotic tRNAs are typically synthesized as larger precursor tRNAs, and these are ...
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1answer
107 views

Is fluoride toxic, and how worried should I be about it?

A recent flurry of "fluoride is bad!" posts are appearing on my social network news feeds. Usually I can simply ignore them after a brief look, but this one, stemming from a recent article in The ...
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Few innervations to blood sugar regulation

Assume you have a case of young female where the intake of 75 grams of pure sugar leads to a rapid peak of blood glucose level (within seconds) plateau phase with very steady blood glucose level ...
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Vitamin D oral intake, transportation and absorption

Several factors affecting vitamin D and its active form absorption and storage acidity of stomach (not significant effect) cytopathic effects of viruses cytopathic effects of bacteria where the ...
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1answer
35 views

H O N C alternatives for organic life?

Most organic structures built from hydrogen, oxygen, nitrogen and carbon. They are represent 1-,2-,3-,4- bond relations (chemical valence) which allow to build variety of chain structures. Are there ...
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1answer
85 views

Transverse diffusion of lipids in red blood cells

The membrane of a human erythrocyte has polarity: Phosphatidylethanolamine and phosphatidylserine are predominantly on the inner side. Phosphatidylcholine and sphingomyelin are predominantly on the ...
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2answers
266 views

Signaling through G protein Coupled Receptors?

There are two different cell lines but we do not know that these cell lines have Gs or Gi proteins, associated with their G-protein coupled receptors. If we wants to know about this. Can we design a ...
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34 views

Early versions of the biochemical pathways wall chart. Where have they gone?

A lot of them in the bin as new versions were released, I imagine. I have been looking for early versions of the wall chart, but I've largely come up empty handed. I did find that besides the ...
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Is life in a supercritical fluid possible?

Someone claimed that the dinosaurs could only live because back then athmospheric density was around 650 kg/m³, providing some buyoncy, this claim is checked on Skeptics SE. The claim itself is beside ...
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1answer
44 views

Why is brown fat brown?

I read in Tortora and Derrickson Anatomy and Physiology that : Another type, called brown adipose tissue obtains its darker color from a very rich blood supply , along with numerous pigmented ...
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2answers
124 views

What are the functions of disulphide bonds?

What are the functions of disulphide bonds between amino acids in proteins or peptides?
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1answer
34 views

Dimerization of Immunoglobulin G

I would like to know the specific determinants for formation of IgG dimers. My understanding is the stem of the antibody is a homodimer of two heavy chains, covalently bonded through two disulfide ...
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77 views

What is most simple eukaryotic genome?

Expressed in number of Base Pairs or Bytes, about how much large is the simplest eukaryotic genome? How much of this is 'junk-DNA' (non-coding)?
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1answer
98 views

What is the difference between vegetable and animal fats?

I often hear from many people saying to waiters - "Please, don't put oil to salad". They probably believe the fat from vegetables has the same impact on the weight as an "animal" fat (meat, eggs, ...
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1answer
102 views

Topology of closed circular DNA

Why are covalently closed circular plasmid DNAs naturally found in an underwound state ? Is it because this makes it easier for the DNA replication machinery to access and unwind DNA ? Or is it ...
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2answers
54 views

How are atoms created? [closed]

From small baby to the old age, we will be grown. We are composed of bunch of atoms, multitude of atoms. When you are grown from baby to the teen age, everyone will say "he has grown!" What do you ...
2
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1answer
60 views

What is optical density in Lowry's protein estimation method?

I have a few questions: What is an OD value? Why do we use blank solution in Lowry's protein estimation method? If The OD of a protein is 0.01, what does it mean? Thanks in advance.
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To increase the stretchability of the ascending aortic arch

The thread about To decrease the amount of proteins in the lymphatic drainage for short term here raised this question. This paper discusses the stretch and Cauchy-stress properties of the heart. So ...