Questions tagged [molecular-biology]

The study of the molecular processes underlying life.

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Book Recommendations: GRE Subject Test In Biochemistry, Cell And Molecular Biology

There are probably a lot of really good answers that may vary significantly in terms of content. I'm looking for a set of books that I can read in preparation for the GRE Subject Test In Biochemistry,...
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what is minimal promoter and what is basal promoter?

what is minimal and basal promoter and what are their elements and what is the difference between the two?I'm confused. searched a lot, but didn't found any satisfactory answer. please help
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Which one is better to use for water stress experiment GWAS or RNASeq?

This is my first time in this area of research. I am working on 95 varieties of bambara groundnut. I have done the agromorphological characterization of these varieties as well as the genetic ...
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Why is the Tm defined as the temperature at which 50% of dsDNA has changed into ssDNA?

In molecular biology, Tm is defined as the temperature at which 50% of dsDNA is converted to its single stranded form. Intuitively it would seem that the melting temperature should have been defined ...
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What causes the elongation of Genome down the evolutionary time line [closed]

Theory of natural evolution says that complex life forms arose from simpler ones e.g. starting from Eubacteria to modern day multicellular eukaryotes. {If we try to reduce these changes happening at ...
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Why do mutations not take place in mRNA of higher eukaryotes?

Is it because it is too short-lived to be mutated? Both DNA and RNA are nucleic acids so how is mRNA protected? RNA viruses undergo mutations to evolve so I guess it is not immune to mutations
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Viral RNA to DNA

I have a question concerning reverse transcriptase. Why is it that when the viral rna is converted to viral dna( as in the case for hiv), the virus develops resistance to medicine? Under what ...
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Why do specifically bananas go brown quicker in the fridge?

Perhaps the title should be: Why don't all fruits containing phenol residues go brown quickly when left in the fridge? Bananas go brown over time because of the oxidation of phenol residues. ...
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75 views

Which are more beneficial: lyophilized or hydrolized collagen peptides?

Looking at two different manufacturing methods for collagen peptides: hydrolyzed vs lyophilized (freeze dried), I read that hydrolyzed results in a hydrophobic biolayer molecule collagen peptide. Re:...
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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 FADH2 enter ...
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Why do we add salt when precipitating DNA?

All the DNA extraction protocols I have seen involve adding salts to the extraction buffer. What is the purpose of the salts? What happens if they aren't included?
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129 views

Why is it thought that protein folding is determined solely by amino acid sequence?

It seems that it is a generally accepted idea that protein folding is completely determined by the sequence of amino acids, but why do people believe that? Is it simply that no example of a protein ...
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Software to model and analyse protein–ligand interactions

I am currently trying to model a certain protein (Golgi Mannosidase II) and compare the induced fit of the inhibitor swainsonine. I would like to be able to analyse the distances between bonding ...
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92 views

Why replication collapse but not stall leads to DNA break?

I have been looking into the concept of replication dynamics and was wondering why collapsing but not stalling leads to a DNA break.
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E. coli & aspartate

I am familiar with the linkage between aspartate/ligand binding, receptor methylation, and flagellar behavior re. style of locamotion, but I do not know what the bacterium does with the aspartate it ...
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When did CRISPR/Cas9 evolve and what is the likelihood that a superior system for live cell genome editing has already evolved on earth since then?

I've read that CRISPR/Cas9 is currently being implemented and tested for its ability to edit genomes in live cells, and that it is supplanting other genome editing tools in labs, such as TALENs and ...
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What is ApoCas9 in the CRISPR-Cas9 system?

I am currently reading an article about a particular assay of Cas9 nucleases. In one of the experiments, they have used ApoCas9 (Apo variants of other CRISPR nucleases) as some sort of control. But ...
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plant uptake of large molecules

I have read several studies concluding that plants can indeed take up molecules with a molecular weight larger than 390 g/mol. Does this mean plants do also take up large molecules like hormones if ...
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1answer
44 views

Non-coding DNA as a protection to deleterious mutations

We know that most part of our genome (at least 75 percent) is non-coding DNA. Can it be a way to protect the organism from mutations in important genes, such as the ones which control cellular cycle, ...
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What Ultimately Controls DNA Transcription?

Transcription of DNA and further splicing of mRNA is regulated by various transcription factors, small nuclear RNAs and so on; similarly such related mechanisms as transposition of transposons. All ...
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Why isn't the human zygote considered a human life how is a living anatomically modern human defined biologically? [closed]

It has 46 chromosomes by default when healthy(Differences almost always are pathological) and has almost every biological functions, processes a Newborn or and Adult person has. It even invades ...
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How can I improve efficiency of Ecoli transformation?

I am an intern in biology institute. I have a 17.3kbp plasmid need to transform to Ecoli. But I have tried many time but have no or very few colony on LB plate. I know large plasmid have less ...
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1answer
53 views

Can denatured GFP show fluorescence?

GFP ( green fluorescent protein) can show green fluorescence. And its fluorescence is due to the tri peptide chromophore which is given in below I was wondering, can we observe fluorescence, if we ...
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How to troubleshoot in vitro formaldehyde fixation for nucleosomes?

For an experiment, I am trying to fix the mononucleosomes (100ng) using formaldehyde as crosslinking agent in HEPES buffer. I have been using 2% formaldehyde in a reaction buffer containing 1mM EDTA, ...
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Does anyone know a good pancreatic-cancer metastasis cell line?

Researching about pancreatic cancer. We have mostly "main-tumor" cell lines in our lab, and I´m currently looking for cell lines originating from metastases (liver, lung, etc.). Does anyone know a ...
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Which animals don't have pheromones?

Which animals are known to not have pheromones besides humans? I can't find any research on this. There are examples of every class that uses pheromones. However nobody seems to answer conclusively ...
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1answer
38 views

How to do desalt reaction by passage through a Micro Bio-spin 6 column?

I want to perform the bisulfite sequencing on rRNA to detect the 5-mC. I followed this protocol • DNA-free™ DNA Removal Kit (Invitrogen) • Purified RNA, Treat RNA according to manufacturer's ...
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Why is the DNA helix anti-parallel? [duplicate]

Why is it that DNA strands are running in anti-parallel fashion? Given the chemical base-pairing, they could have been parallel just as well.
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Difference Junk DNA and Pseudogenes [duplicate]

1-Are Pseudogenes and Junk DNA both Non-Coding DNA or they are different entity? How much Pseudogenes & Junk DNA do we have respectively? 2-I read that Non-Coding DNA has functions, my question ...
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Holder for 75 mm x 25 mm glass slides that can handle vibration

Hello Biology Stack Exchange, I have an application where I have cells on a glass slide (dimensions: standard 75 mm length x 25 mm width x 1 mm thick). I want to vibrate/shake the cells rapidly ...
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How to generate protein graphics for illustrating articles?

The structure of insulin shown below appears in a Wikipedia entry. What software was (or can be) used to create pictures of this type?
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Why are so few foods blue?

Although blue foods exist, they're rare enough compared to other foods for food preparers to use blue plasters as a convention. The natural colour of a given food is due to pigments that have some ...
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1answer
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Does this article call into question the theory of evolution?

https://www.quantamagazine.org/neutral-theory-of-evolution-challenged-by-evidence-for-dna-selection-20181108/ The article above challenges how mutations work in evolution. Does this disprove the ...
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37 views

Why do people use J2 viruses for macrophage immortalization?

I've been trying to figure out how to go about immortalizing some primary alveolar macrophages harvested from mice. What I am seeing in the literature is that it seems like people have been using a ...
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71 views

What is the subcellular location of synthesis of non-essential amino-acids?

What is location of non-essential amino acids synthesis in a cell? Is it some specific organelle? And what is the gene driver behind this? I thought the whole point of DNA is coding for how to ...
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1answer
62 views

What is the role of CRISPR-dCas9 in gRNA-dCas9 transcription regulator complexes?

In this paper1, I read that mutant versions of Cas proteins such as a deactivated Cas9 (dCas9) are used alongside a guide-RNA (gRNA) to form variants of CRISPR tool that can function as transcription ...
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Biochemistry of pleasure of/desire for physical exercise in mammalians and humans?

Are there some known biochemical mechanisms, that induces desire for/pleasure of physical exercise in mammalians and humans? I have heard, that horses can not live without physical exercise and they ...
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31k views

Catabolic and Anabolic Reactions

How do we differenciate between catabolic and anabolic reactions? According to my researches; Catabolic Reactions Catabolic reactions (also called “catabolism”) break down larger, more complex ...
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What buffer should I choose for IEX chromatography for purifying IgY

I will use ion exchange chromatography with an anion exchange column to purify chicken IgY. Prior to this I did dialysis to remove salts from previous purification steps, is it possible after this ...
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Chemical inhibition of fertilization in plants

Are there any chemical compounds that inhibit fertilization in plants after gametogenesis? Simply put, I am talking about spermicide or emergency contraception for plants. Specifically, I am ...
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1answer
45 views

Application of molecular dynamics simulation (or alternatives) for the full pathways of protein interactions?

If one would like to control the biological system (e.g. to treat disease or aging/senescence) then one should introduce the drugs in the system, that initiate complex protein interaction pathways ...
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ATP and Muscle Contraction

I have a question regarding how molecular interactions manifest in physical actions - such as hanging from a bar. To the best of my understanding, when it comes to the contraction of muscles, ATP is ...
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1answer
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Can I use a basic compound microscope to analyze the ploidy of plant chromosomes?

So, I'm not really any kind of trained botanist. But I do have two things: some dandelion seeds from France, and, collecting dust in my garage along with related accessories, this thing. Normally, ...
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263 views

What is the meaning of “Rb is in the active state”?

I am reading about cyclins, cdks and Rb (Retinoblastoma) and some of the terminology is not clear to me. I understand that when CDK phosphorylates Rb, it disconnects from E2F, and E2F can act as a ...
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How do receptors lose their sensitivity?

Recently, I learned that one of the causes of Type II diabetes is that insulin receptors on cell surfaces lose their sensitivity due to long-term high exposure to insulin (which occurs as a result of ...
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Does the lack of “mirror life” tell us anything about abiogenesis?

My (extremely rudimentary) understanding of Biology is that many of the building blocks of life are chiral and that life on earth is entirely made up molecules with the same chirality. Does this ...
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1answer
153 views

How are single-stranded binding proteins removed from the lagging strand during DNA replication?

The lagging strand, downstream of the Okazaki fragment, is covered in single-stranded binding proteins (SSBPs) during DNA replication. What is the mechanism which ensures that SSBPs are removed from ...
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What is the relationship between Ca- and Na-ions and mucins and why?

According to Wikipedia https://en.wikipedia.org/wiki/Mucin#Secretion mucins (Proteins that form mucus) obtain viscoelastic properties by the Exchange of sodium and Calcium Ions. What is Happening ...
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Are my plasmids single-stranded?

Hi, in this agarose gel photo (70 volts, 3.5uL Gel Red in 30ml of TBE, 1% Agarose, 1 hour run), I've checked the digestion of a large plasmid (15Kbp, one cut site). The theory says that the digested ...
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Is the lac operon repressed in the presence of both glucose and lactose?

In the presence of both sugars (glucose and lactose) will there be repression of the lac operon completely? I know that more glucose means less cAMP --> less CAP --> less positive regulation, and ...