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

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What is the role of Glycine in SDS-PAGE [duplicate]

We are using glycine in SDS-PAGE running buffer. What does it actually do? I found out that it maintains the pH and prevents sample damage. Does it play any other role and can it have any alternative? ...
5
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1answer
146 views

enzymes that stabilize DNA loops

As a follow-up of a previous question, I would like to know what enzymes or protein complexes have been used to manipulate DNA samples into stabilizing DNA loops. I have read that cohesin is one of ...
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3answers
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What's the difference between shotgun sequencing and clone based sequencing?

In a lecture during my undergraduate degree we were introduced to the race to complete the human genome. Celera were competing with Sanger and collaborators to sequence the human genome. Celera ...
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Plant symbiosis, alternative regulation pathways to AON and miRNA399?

I am currently studying systemic repression of both arbuscular mycorrhizae and nitrogen fixing bacteria in legumes. I know of the AON pathway (which works through CLE and NARK). I also know of ...
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1answer
81 views

Why is an A-U bond less stable than an A-T bond?

I have encountered the following fact many times, but have not yet encountered a possible explanation for it. Will you please help me understand the molecular mechanism by which the bond between ...
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4answers
804 views

Why are amino acids in biology homochiral?

Why are nearly all amino acids in organisms left-handed (exception is glycine which has no isomer) when abiotic samples typical have an even mix of left- and right-handed molecules?
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1answer
76 views

Can difference in the expression potential of alleles lead to dominance?

Several hour ago I was in thoughts what allele dominance really means on molecular level. As we know from basic genetics, if the organism had Aa type of some gene ...
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1answer
37 views

Yeast Strain with squalene synthase / farnesyltransferase (ERG9) gene deleted

I was interested in obtaining a yeast strain without the enzyme farnesyltransferase (Which catalyses conversion of FPP to Squalene). The Euroscraf database has thousands of yeast strains with ...
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1answer
45 views

Genomic DNA resuspension after ethanol precipitation

I am having trouble resuspending purified human genomic DNA. The genomic DNA is purified using phenol:chlorofom from ~ 1 mL of blood. After ethanol precipitation, I normally see a large pellet which ...
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2answers
83 views

How to safely conserve my current DNA methylation marks?

I read the Wikipedia article on DNA methylation Let's say I want to extract and then stock my current DNA methylation marks somewhere so that I can use it safely 20 years in the future for a medical ...
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2answers
43 views

difference between transcriptional activator and general transcription factors?

What is the difference between transcriptional activator and general transcription factors? Are they same or different, and do the transcriptional activators first attract general transcription ...
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0answers
52 views

Genomic DNA extraction protocol by salting out with NaCl, how to improve yield

In these papers A rapid non-enzymatic method for the preparation of HMW DNA from blood for RFLP studies A simple salting out procedure for extracting DNA from human nucleated cells Modified ...
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1answer
35 views

How much time do the different mechanisms of gene regulation need to take effect?

I am thinking of the major regulatory mechanisms, like general transcription factors, activators, repressors, and RNA interference. If non-active regulator genes using each of the different ...
7
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1answer
54 views

Does copper exacerbate wounds?

There is a three edged stiletto (weapon, not shoe) with a triangular cross-section that is often touted as being "extra dangerous" because of the triangular puncture it makes, and its copper ...
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2answers
2k views

Why is there more variation in proteins than genes?

The Genome of a cell or organism is the same as that of the entire organism. However, the proteome of an organism is much greater than that of each cell (unless the organism is unicellular). How do ...
4
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1answer
47 views

A good software for agent based modelling?

Hello i'm gonna start my master degree in systems biology and i'm thinking of working with agent based modelling, but i really don´t know which platform can be the best to simulate interactions ...
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2answers
92 views

Why mutations in genes involved in general processes like DNA repair increase the risk of developing specific types of cancer?

For example, mutation in MHS2, which encodes a protein involved in the repair of mismatches that occur during DNA replication, dramatically increases the risk of developing colon cancer. (There are ...
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1answer
19 views

When should you use a stringent plasmid

I was wondering if anyone had good examples of when you would want to use a stringent plasmid vs a relaxed plasmid in a research setting. Thanks
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0answers
27 views

Do any gaps in DNA during cell division (meiosis in particular) lead to crossover?

I have some gaps in the knowledge abour crossover. I know, that crossover is connected with reparation process. I'd like to know if all gaps in chromosomes lead to crossover (reparation based on 2d ...
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1answer
77 views

Goodwin oscillator explained

Hello I have been reading papers about the Goodwin oscillator and I found that the equations are kind of tricky. Specially the part of the hill coefficient. In his paper "An entrainment model for ...
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1answer
33 views

Why do RNAi pathway proteins exist in the nematode when they can cause them harm?

When dsRNA is injected in plant, Dicer cuts it and prevents disease. Why would the plant parasite, M. incognita - a nematode, die when dsRNA was injected in it? It should have saved it. Again, to be ...
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0answers
26 views

Artificial Synthesis of Animal Cells

If we know the elements with which a certain type of cell is composed of (I am particularly talking about Animals, and Humans more importantly), why aren't we able to make cells on our own then, in a ...
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0answers
25 views

UV light-induced mutagenesis during gel extraction

this is a very short question I did not find the answer for online, neither on this nor other fora. At the beginning of my cloning protocol, I extracted the band with the sequence of interest directly ...
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0answers
17 views

de novo gene synthesis vs cDNA library creation from plant RNA: Pros & Cons

What are the relative pros & cons of the following two approaches when one wants to insert a known, sequenced plant gene into a target host organism: de novo gene synthesis vs plant matter ...
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1answer
15k views

Why is ATP the preferred choice for energy carriers?

Why is ATP the most prevalent form of chemical energy storage and utilization in most cells?
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1answer
89 views

How the chaotropic agents help in purification of DNA molecule?

Those plants which are rich in secondary metabolites and polysaccharides DNA isolation can be done using certain chaotropic agents? can any one explain how it works?
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1answer
58 views

Why does Taq polymerase add 3' adenine overhangs?

Is there a mechanism for the preference of Taq polymerase to add a non-templated 3' adenine (overhang) instead of other bases?
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1answer
50 views

What are the problems in using an ssDNA or an mRNA for expression instead of using a plasmid?

Let's say you want to do a gene cloning experiment. You have an empty expression vector (mRNA or DNA) and are looking to clone some gene X into it. Why is it you can only buy X already inside a vector ...
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1answer
27 views

Synthesis of an additional DNA in Pachytene and Zygotene [closed]

I've read, that in Pachytene and Zygotene additional DNA material is synthesized, about 0,3, 0,1% respectively. Why is it so?
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1answer
39 views

How RNA primer on leading strand is removed during DNA replication and how the gap is filled? [closed]

Please can you explain me how the gap created by the removal of primer on 5'-3' leading strand is filled.
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3answers
287 views

How does the body switch between aerobic and anaerobic respiration?

Lets take the case of a person doing heavy exercise. Aerobic respiration is taking place, but oxygen is about to be finished up. Glycolysis occurs, Krebs cycle finishes. Now NADH and FADH enter ...
3
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0answers
32 views

Are all genes transcribed in differentiated cells?

My textbook tells me that it’s specific transcription factors that allow for a different set of genes to be expressed in different cells (differential gene expression). My book gives the example of ...
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1answer
35 views

does life make or break?

Ok, this question seems like it may be impossible to answer, but would be interesting to see if anyone has an idea. Throughout the course of a human life, do we make more molecular bonds than we ...
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1answer
114 views

The mechanism of mechanoreception?

I am interested in knowing the molecular mechanism behind mechanoreception/mechanotransduction (i.e. mechanism behind receptor potential generation on mechanical stimulation). I know that most ...
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1answer
95 views

An experiment to test if a bacterial resistance gene is on the plasmid or chromosome?

So I have an E.coli strain phenotypicall resistant to the antibiotics ampicillin and rifampicin. How do I test if the AmpR gene is carried on a plasmid and not on the chromosome? In summary, I ...
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1answer
19 views

Molecules, Targets and Isoforms

I have a question. Given a molecule A and two isoforms of a gene X, Y, and the knowledge that A targets X. Can I infere from this anything about whether A targets Y? As a motivation think about ...
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Are there in biololy specific QM-phenomena which are necessary for their processes?

Of course QM should be every where, because that is how nature is. But for example if you take the fusionprocess of our sun it appears that the sun wouldn't give any heat and light without making use ...
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0answers
34 views

Artificial reduction of NADP into NADPH by means of an electrical current

I've recently been attempting to artificially drive the formation of NADPH via the NADP reduction mechanism utilized by Ferredoxin-NADP Reductase in the Light-Dependent Reactions of Photosynthesis in ...
2
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1answer
50 views

Why does protein kinase C activated by different means have different effects?

I could be way off base but I think I remember learning that Protein Kinase C has some effects when activated by one pathway and other effects when activated by another. How does this happen? Is it ...
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1answer
72 views

Is a bone marrow transplant limited by sex?

Can a female patient get transplanted with bone marrow of a male donor and vice versa?
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1answer
348 views

Restriction enzymes, how are the recognition sequences determined?

How were the recognition sequences (e.g. GAATTC of EcoRI, GGATCC of BamHI) characterised? Text books only list the recognition ...
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2answers
73 views

Is there a metabolic pathway that generates methanol?

I've been looking for help topics about methanol in metabolism. Specifically, I wish to know what is a common dietary component that generates methanol following metabolism and comment on its ...
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1answer
75 views

What is two-start or zigzag model of 30 nm chromatin fibre?

I read some webpages describing the two-start model but could not get it. I'll be obliged if someone helped me understand the topic. The websites I have been through are: ...
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2answers
110 views

Is it possible to create a restriction map using python? [closed]

I have some fragments of DNA from single and double digests using three different restriction enzymes. I'm trying to construct a restriction map of a linear fragment of DNA. The map needs indicate the ...
3
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0answers
45 views

How can a mutator gene can cause a mutation when it is shut off? [closed]

defination of "Mutator" - a gene that increases the rate of mutation of one or more other genes. However, in the book "Molecular Biology of the Cell" (bruce alberts) it states that when a mutator is ...
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0answers
175 views

Construct a restriction map of a linear fragment of DNA using the following data?

I've attempted to do the single digests, and the double digests, but cannot complete the map.... I've attached what I've done so far DNA Sizes of Fragments (bp) uncut DNA 900 DNA cut with EcoRI ...
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0answers
19 views

Enzyme immobilization: Factors that help or hurt success

Are there any factors to consider that can help / hurt the chance to get a successful immobilized enzyme catalyst? i.e. The relative attractiveness of a live host synthesis vs an immobilized enzyme. ...
1
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1answer
44 views

Lookup for transporter locations in humans

I am interested in several transporters and cotransporters (eg SLC12A1/2 and many others), more precicely, in (human) organism that are made of cells containing those transporters. So does anyone know ...
8
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2answers
249 views

How does LCR compare to Assembly PCR

The question pretty much explains itself. How do the two methods compare? I've always used Assembly PCR but the method is prone to mistakes and I'm curious how it compares to Ligase Chain Reaction ...
2
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2answers
39 views

What separates gene loci?

Introns are sections of noncoding DNA that separate exons within a gene locus. However, between different gene loci, I also would assume there to be noncoding regions of DNA. What are these regions ...