The study of the molecular processes of the nucleus and cell function.

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397 views

How does non-homologous end joining (NHEJ) work?

I was reading about non-homologous end joining (NHEJ) in my molecular biology of the gene textbook but the explanation provided in the text was rather vague to me, and I was not able to understand it ...
2
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3answers
174 views

Why doesn't the cytosol dissolve the polar structures?

we know that cytoplasm of cells are filled with water molecules and other hydrophilic molecules so my question is why the water of cytosol doesn't dissolve the ionic part of the lipid bilayer or why ...
2
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1answer
82 views

Is the protein in teardrops still attached to cells, or is it released and free-flowing?

A ScienceDaily article says that the protein in teardrops can kill bacteria. But how does it reach the bacteria?
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2answers
58 views

What is meant by nucleated in this context?

Hi I am little confused in one of my classes; because the teacher will say that " the actin is nucleated by the ARP 2/3 complex" or "microtubles are nucleated by the centrosome". Unless I am ...
2
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1answer
89 views

How small does a nanobot have to be to “swim through the brain” and access any neuron it wants to?

I read on this question What is in the space between neurons in a brain? that there is actually not much empty space in a brain. But my question is slightly different. Is there a visual demonstration ...
2
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1answer
118 views

Substitute 25mM dNTPs mix with 10mM dNTPs

I need to make a solution of multiple compounds, one of them is dNTPs. The recipe calls for 20 μl 25 mM dNTPs in a 1250 μL master mix. Unfortunately I do not have it available at that concentration, ...
2
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1answer
118 views

Cloning of a sheep.. Dolly?

Dolly the sheep was a clone. When she was born she was eight years old on her 1st day of birth, her mother (from which she was cloned) was also eight years old. What is a molecular reason behind this ...
2
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2answers
124 views

Prenatal Marketing

This is for a short story idea. Is it possible to modify the DNA of a child to make their metabolism more susceptible (physical response, addiction, etc) to a certain type of chemical i.e. a chemical ...
2
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3answers
87 views

Is DNA mutation locally energetically stabilizing the DNA molecule

I am no biologist, but as a physicist, a spontaneous mutation (seen as a chemical transformation) should lower the energy of the system, at least locally. So I wonder if any research has been done ...
2
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1answer
52 views

DNA polymerase in PCR (polymerase chain reaction)

Can the DNA polymerase in PCR (polymerase chain reaction) recognize both DNA and RNA for use them as template? I want to know is it possible if my primers bind to an contaminant RNA and then any DNA ...
2
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1answer
32 views

Electroporation of one-cell embryo?

Would electroporation be successful on a one/two-celled mouse embryo? If it would, what buffer could be used and what percentage of cells would be viable? Thank you.
2
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1answer
56 views

Why do oncogenes show genetic dominance?

As we know that tumor suppressor gene causes cancer only when both the alleles are recessive in nature.But in case of oncogenes if only one allele is dominant it can cause cancer.Why in case of ...
2
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1answer
341 views

Why does the pET- expression vector contain a LacI gene additionally to the one in the genome?

The pET plasmid is used for protein expression with T7 promotor in expression strains, such as E.coli BL21(DE3) It contains a lacI gene which codes for the lac repressor protein, a protein of ...
2
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1answer
60 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 ...
2
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1answer
1k views

What's the physical meaning of Svedberg unit?

Sedimentation coefficients, using a centrifuge, are expressed using Svedberg unit (symbol S, sometimes Sv). Wikipedia states that $S = 10^{-13}$ sec but I also saw in a book that actually $S = ...
2
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6answers
235 views

Sequence analysis software suites

I have used DNAStar laser gene and VectorNTI in the past for cloning, primer design, sequence alignments, etc but no longer have access to these. Are there any comparable replacement suites or what ...
2
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1answer
383 views

Elution of biotinylated RNA

I am using Neutravidin Agarose beads to isolate biotinylated RNA. The thing is, in the manual it says to use 8M Guanidine-HCl, pH 1.5 for elution biotinylated molecules. As far as I know it is a very ...
2
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2answers
88 views

How does promoter sequence affect initiation?

I don't know if this might have been highlighted in recent research, but a textbook I have states that "the exact way in which promoter sequence affects [transcription] initiation is unclear" I'm ...
2
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1answer
97 views

What will happen if we expose the brain to an intermittent light?

If a brain is exposed to an intermittent light are specific areas going to fire? If yes, which of them? Is there any experiment about this?
2
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2answers
91 views

Termination of translation

What dissociates first - the last tRNA, mRNA and release factors or the subunits of ribosomes? I tried searching this from Lehninger but couldn't get a clean answer.
2
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2answers
527 views

Beginning with centrifuge experiment

This is the first time I do a centrifuge experiment with my own centrifuge machine, it's just simple made by a rotor that can rotate the tube at high speed. As I know a centrifuge machine can be using ...
2
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2answers
187 views

Do the simplest bacteria have ribosomes and helicase?

I find it interesting that all life on earth use DNA. I've seen video on how helicase and ribosomes work together to copy DNA sequences (to RNA) with helicase then recreate them using ribosomes. Does ...
2
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1answer
41 views

Is nuclear DNA immuno-privileged?

It is well known that if DNA occurs in the cytoplasm of eukaryotic cells, an immune response may be triggered through a myriad of DNA receptors and pathways as part of the immuno response. Yet, ...
2
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1answer
27 views

Does mung bean nuclease cleave a phosphate group when it's chewing off 5' or 3' ssDNA ends?

I'm looking to create blunt ends from sticky ends with mung bean nuclease for subsequent ligation. Does anyone know full mechanism by which mung bean nuclease will do this? In particular after the ...
2
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1answer
32 views

What are host cellular factors?

With respect to this paper: Global Analysis of Host-Pathogen Interactions that Regulate Early-Stage HIV-1 Replication What does the term "host cellular factors" mean??
2
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1answer
1k views

What are some of the general characteristics of the DH5 alpha strain?

I can not find some useful sources unfortunately. Please tell me about some important characteristics of DH5 alpha. What makes DH5 alpha suitable for the gene cloning?
2
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1answer
26 views

epitope prediction/ mapping

B-CELL EPITOPE PREDICTION Regarding this article: "Such a molecule can be synthesized or, in case of a protein, its gene can be cloned into an expression vector."----- is a particular line in ...
2
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1answer
57 views

Immunodominant Peptide

Can someone please explain me the concept of Immunodominant peptide in simple language?? I did read the wiki article but did not understand it clearly. Please help! (I have not studied biology since ...
2
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2answers
368 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. ...
2
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1answer
60 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 ...
2
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1answer
103 views

What are the Gateway clonase enzymes?

The Gateway cloning system utilizes what Life Technologies refers to as "Clonase enzyme mix" to catalyze the BP and LR reactions. What is in this enzyme mix? Is there a sequence for them?
2
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1answer
67 views

Do you have experience with PacBio?

I prepare a experiment and I found $PacBio SMRT$ as the great way to sequence my PCR products. I find the cost: library preparation 655 dollars + sequencing 435 dollars. It seems very low. Do you have ...
2
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1answer
63 views

Would expression of GroEL and GroES in erythrocytes be a potentially effective therapy for sickle cell disease?

Would expression of GroEL and GroES in erythrocytes be a potentially effective therapeutic strategy for sickle cell disease? Why or why not?
2
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2answers
2k views

Explanation of the terms “downstream signaling” and “upstream signaling”

In molecular biology, what's the meaning of the terms "downstream signaling" and "upstream signaling"? What's the difference between them?
2
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1answer
127 views

DNA ligase mechanism

I am unable to understand what happens to the phosphates from ATP. What are they used for ?Charging 3' end or 5'end ?
2
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2answers
267 views

Why did Fair Meiosis evolve?

How and why did Fair Meiosis evolve? I can hardly think that it provided a fitness advantage to the individual carrying the mutation. Why would it? Or did it evolve through lineage selection? Or was ...
2
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1answer
62 views

How do cells figure out the big-picture shape?

I'm wondering what makes cells to divide (and stop) in such a way that they make our hands the shape that our hands are...
2
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1answer
1k views

Why is Sanger sequencing inferior for detecting SNPs in cancer cells?

I am familiar with Sanger sequencing, but at the level of an undergraduate. A lecturer of mine tried to describe Sanger sequencing as losing the sequence information in noise when used to detect ...
2
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1answer
30 views

What happens to IP3 molecules after release from IP3 receptors?

IP3 molecules bind to IP3 receptors and open up the calcium channels on the endoplasmic reticulum. I am wondering what happens to IP3 molecules after they have been released from the IP3 receptor? Do ...
2
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1answer
63 views

Is the amount of dNTPs rate limiting for very long PCR products?

I'm using the Q5 system and I'm PCRing a product that will have a final length of around 9500 bases. I have noticed that the product is there but very faint. The primer seems to be used up. So my ...
2
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1answer
21 views

What is the protein sequence taken as input in the Path-A prediction system

Considering the Path-A based metabolic pathway prediction (http://nar.oxfordjournals.org/content/34/suppl_2/W714.short). It uses machine learning for pathway prediction. Suppose that the input was a ...
2
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1answer
39 views

Retrovirus Production

I have been having difficulties with low transduction efficiencies of my retrovirus production. I expand my plasmid of interest (on MiG-GFP plasmid) in DH5α E Coli for ~24 hours, purify with Qiagen ...
2
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1answer
111 views

Why does gaining a hydrogen in biology considered reducing a molecule? [closed]

I've learnt in chemistry that gaining electrons means reduction, while losing electrons means oxidation. But why is it in Biology textbooks I sometimes come across the term gaining hydrogen??
2
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2answers
256 views

Why people fear GMOs? Can't we map a plant composition?

My main question is can we map what a fruit is made of? For instance apples are made of 0.0002% of protein X, 0.00001 of protein Y, 0.001% of amino acid Z... etc... If we can, then my next question ...
2
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1answer
41 views

Concentration of degenerate primers should you dilute to?

I'm a little embarrassed to ask but when you have for example four degenerate primers and the end protocol says that the final primer concentration should be 10 µM working stock, should you make the ...
2
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1answer
44 views

How are lesions in the RNA corrected?

I quite understand why thymine is present in DNA. So we can mark it out where cytosine undergoes a reaction and is converted to uracil. Then we can repair the DNA. But how can we make that out in RNA ...
2
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1answer
57 views

How do C. elegans manage nutrition?

If there is ample amount of food, do C. elegans worms know when to stop eating or do they store extra energy? Could they put this extra energy to use by moving faster or putting more eggs?
2
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1answer
341 views

Difference between sequential and conformational epitope

Is the difference only in its structure? Like conformational epitope has 3D structure while sequential has a linear structure?(I have not studied biology since last 8 years and now I am going through ...
2
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1answer
30 views

Transcription rate expressed in microarray per hour

This article gives measurement of transcription rate and the unit they're using is microarray per hour. For example, at 27°C the average expression of their genes is 236.1 microarray per hour (page ...
2
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1answer
38 views

Why can't NMR be used on large RNA molecules?

While reading my Molecular Bio textbook, I came across a sentence that stated that NMR cannot be used on large RNA molecules to determine their structure. Why is this? Is it because RNA is single ...