6
votes
2answers
238 views

Ni-NTA purification, problem with the chaperone protein

I'm trying to purify the protein by Ni-NTA affinity chromatography. It seems that my protein (size about 54 kDa) is co-purified with chaperone protein (probably GroEL - as the band is around 57kDa). ...
2
votes
2answers
215 views

What are the naming conventions for mutations of proteins?

I have been reading about Maltose Binding Proteins. Mutant forms of the molecule seem to be named MalE_ where the _ represents a number, for example MalE36 or MalE50. Please can someone explain the ...
0
votes
1answer
41 views

Can TGF beta family induce all somatic stem cells?

I think this is not possible. Conclusion about this preview article TGF-$\beta$ family signaling in stem cells: While TGF-$\beta$ family signaling regulates stemness of normal and cancer stem ...
2
votes
1answer
78 views

Why some neurons are tetraploid

Why are some neurons tetraploid, and how does this result from it's ancestor cell ?
2
votes
2answers
872 views

How many recombination events are there per generation in humans?

I'm looking for a reference that tells me how many recombenation events occur in humans from one generation to the next. Assuming that the human genome is a 3.3 GigaBases long DNA sequence, how many ...
0
votes
2answers
124 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.
8
votes
1answer
177 views

A question about the intersection of evolution and thermodynamics

From this 2014 article in Quanta magazine by Natalie Wolchover there is a quote from a physicist with an intriguing idea about evolution: “You start with a random clump of atoms, and if you shine ...
0
votes
1answer
55 views

Does melatonin change the appearance of humans?

Melatonin (not to be confused with melanin) was sold as a wonder drug during the 90s. I remember images of mice, which supposedly got a more beautiful fur. I would like to know whether the effect is ...
1
vote
1answer
29 views

Silene virginica Endangered in FL

Why is Silene virginica, colloquially known as Fire Pink, endangered in Florida? What factors besides human industrialization are affecting its survival there?
0
votes
1answer
36 views

Breaking a gene during recombination

I just started reading about recombination frequencies of genes and related stuff, and can't find an answer to this (possibly naive) question. Can recombination possibly "kill off" a gene ? To be ...
3
votes
2answers
300 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 ...
3
votes
1answer
695 views

What are hot spots on human body?

Recently I have just discovered that a certain amount of the mobile phone frequency can be absorbed by human tissues. For example, this is the SAR info of iPhone 4s: Head: 1.180 W/kg 1 g Body: ...
2
votes
1answer
76 views

What is the focus distance of a 3D screen?

I've thought long and hard about wheter this is the appropriate section for this question, because I guess it's kind of an interdisciplinary subject. My understanding of stereopsis (please, correct ...
1
vote
1answer
73 views

Can tubular secretion regarded as local hormone?

Tubular secretion is : The process in which ions and other waste products are transported into the distal tubules of the nephron. can it be regarded as local hormone??
1
vote
1answer
238 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 ...
6
votes
2answers
1k views

Do women have testosterone?

In a documentary on fitness I saw it was stated that women can't get big like men because of their low concentration of testosterone. If it is true that women have testosterone, where is it made? Why ...
7
votes
1answer
299 views

Can HIV be transmitted via breastfeeding?

If a pregnant women is HIV positive and she is treated with medicines to deliver a normal child,can she transfer the HIV virus back to her normal HIV free child by colostrum?
1
vote
0answers
63 views

Solunar theory of animal activity

Solunar theory, which states that animal activity in wild (fishes, deer) depends on position of sun and moon in sky. Based on the solunar calender, hunters seek for optimal time for hunting fishes. ...
2
votes
2answers
671 views

Single stranded DNA in gel electrophoresis

From http://www.nfstc.org/pdi/Subject05/pdi_s05_m01_01.htm : ... The separation medium contains a denaturant in order that the electrophoresis is conducted on single-stranded DNA fragments. ...
7
votes
1answer
2k views

How tolerant are ants to cold?

There was a trail of what are commonly known as sugar ants (small, brown, hyperactive) in my kitchen. Three of them walked onto an ice tray placed in their path. They only walked a short distance on ...
6
votes
1answer
106 views

Can we really 'discover' 85% of mammalian viruses?

This virology [blog] discusses estimates of the number of mammalian viruses and the costs of 'discovering' 85% of them. My question is whether this is not a forlorn hope. The ".632 rule" in ...
8
votes
2answers
60 views

What are the ecological effects of moderately high and prolonged concentrations of nitrogen deposition on an ecosystem?

There are many sources of nitrogen which eventually get deposited out of the atmosphere and onto the land/surface. Typically higher levels of nitrogen compounds are emitted near urban and roadway ...
2
votes
1answer
98 views

On which part of the DNA will the new DNA nucleotide connect? [closed]

My question is: Where will the new DNA nucleotide connect on the (part of the) DNA shown on the picture? Will it connect to the phosphate group? What does the 5' --> 3' mean? Thank you in ...
1
vote
0answers
196 views

Why does low temperature make RuBP, GP and TP concentrations fall in Calvin cycle?

In my A level revision guide and places on the internet it states that at low temperatures levels of RuBP, GP and TP all fall. However I don't quite understand how this is the case, because as far as ...
3
votes
1answer
103 views

Regarding the NCBI FTP site

I am trying to extract information about SNP data from the FTP server of NCBI. Could someone please explain to me how the directory is organised? There are many many files and folders and I can't ...
6
votes
3answers
8k views

Why does the oxygen produced in the photosynthesis come from water and not CO$_2$?

In the photosynthesis equation $$6*CO_2+6*H_2O+sunlight\rightarrow C_6H_{12}O_6+6*O_2$$ the only place where we have 6 molecules of $O_2$ is in the $6*CO_2$. Then it reacts with $H_2O$ to form ...
2
votes
1answer
504 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? ...
1
vote
1answer
109 views

Anatomy suffixes?

Here are some suffixes I want to know their meaning: -ium: trapezium (carpal bone) -ius: trapezius (column muscle) -ous: Talous and calcanous (tarsal bone) -alis: Acromialis, Ulnaris (shoulder ...
1
vote
2answers
3k 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 ...
1
vote
2answers
89 views

Cancer cure statistics questions

I have a question about cancer cure statistics. Many of the cancer literature or databases I have come across speak about 5 year or 10 year survival rates. In this case survival means that the patient ...
4
votes
1answer
367 views

What happens to fecal matter if it's continually re-eaten?

After class today, the topic of eating one's one fecal matter came up. There was a sharp divide as to how people thought the defecations would change. I realize this is a bit of an odd question but ...
1
vote
1answer
96 views

Why are hens so different from other birds? [closed]

Hens lay many eggs during their lifetime (at least, I don't know of one which can lay more eggs) and they can't fly. Compared to other domestic animals it seems to me they are the least capable of ...
0
votes
1answer
71 views

Why are some chemical dangerous to aquatic environment only?

Recently I was changing the thermal grease on my PC. I have noticed on the back of box, that the grease is not dangerous when ingested or when touched. But there was specifically stated, that is ...
3
votes
1answer
2k views

What is the biological function of nose hair?

What is the biological function of nose hair? In general, can we consider underarm hair and pubic hair to be vestigial structures?
9
votes
3answers
15k views

What's the worst that can happen from eating too many spicy peppers? Can you die?

Some peppers, such as the habanero or Carolina reaper are extremely spicy, and when eaten in larger amounts than one is accustomed to, can cause some discomfort. I've also heard anecdotes claiming ...
5
votes
2answers
483 views

Is there an antagonistic association between Penicillium and Aspergillus?

Some Aspergillus species appear to like walnuts. My question concerns the association of Penicillium and Aspergillus. No sooner does Aspergillus colonize a walnut (or some other challenging carbon ...
2
votes
2answers
70 views

Valid comparison of gene expression between several genes in several cell lines

We have gene expression data (Affimetrix mRNA gene expression results) for several cell lines, over a set of genes. Our goal would be to be able to compare relative gene expression for genes over the ...
0
votes
0answers
30 views

What exactly are “floaters”? [duplicate]

i was reading this artical after hearing about it on the news, while reading i saw the term "floaters" which made me remember of a recent Family Guy Episode in which there is a joke about them in ...
4
votes
1answer
216 views

Epistasis Involving Multiple Loci

The following problem is from Schaum's Outlines on Genetics, 5th edition, by Elrod and Stansfield. I'm having some trouble solving it. It is found under a section entitled "Interactions with Three ...
2
votes
1answer
673 views

Difference between flexion and contraction?

i asked this to my anatomy teacher and he said there is no difference but when it comes to specialy in body building when you say to flex their bicep they freeze their upper limb in order to do that ...
2
votes
2answers
161 views

Is the tomato a very very close relative of the pepper?

I ask because if you look at a tomato, the way it grows on a vine, its color, the texture, and make up of its skin and internal structure it seems very much like a pepper. The only thing I can think ...
5
votes
3answers
535 views

Why are there no tree-like plants that grow in lakes?

Looking at aerial photos of boreal forests, with dense woods clear-cut by quiet lakes, I wondered why exactly are the woods so clear-cut at the edge of water? Why won't trees develop adaptations that ...
3
votes
1answer
110 views

What is the fastest but not venomous snake?

Is it known which non-venomous snake can attack most quickly? I guess it is a snake that attacks its opponent by bites, and not some kind of constrictor.
5
votes
1answer
87 views

Are Lambic beers the product of quorum sensing?

Lambic beers are a Belgian specialty which is still made by open-air "inoculation" by airborne microbiota first, followed by additional yeasts, LAB bacteria and more joining in at the time of ...
6
votes
2answers
202 views

Tap vs. mineral water for drinking

I was told a human should drink a small glass (0,3 liter) of mineral water per day to get the minerals. What is the rationale behind this? What is the difference between tap water and mineral water in ...
2
votes
0answers
130 views

Transportation of bacteria

I would like to take an apparatus containing bacteria to another country (Bolivia) from the U.S.. How do I determine whether I am allowed to do this? The bacteria are: ...
1
vote
1answer
78 views

Religion and Genetics

Are there studies that investigate the heritability of believing in supernatural things (or related concepts)? Or stated differently. Are there studies that ...
2
votes
1answer
114 views

What does “thermodynamic equilibrium” mean for an enzyme-substrate complex?

From Fersht, Enzyme Structure and Mechanism p. 87: The Michaelis-Menten mechanism assumes that the enzyme-substrate complex is in thermodynamic equilibrium with free enzyme and substrate. In ...
1
vote
0answers
185 views

Is the default kmer 25 value in Trinity still ok for assembly of 150bp reads from Illumina HiSeq 2500?

I will soon be receiving Illumina HiSeq 2500 data (150bp PE stranded reads). In the past we have been using Trinity as our assembler of choice, but it uses a default kmer value of 25. I believe this ...
5
votes
3answers
252 views

Protein structures given in PDB and SNP's

There are millions of proteins given in PDB, the sequence for which we can download in FASTA format. There are also hundreds of SNP's given in NCBI dbSNP. My question is whether the proteins in PDB ...

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