Questions tagged [molecular-biology]

The study of the molecular processes underlying life.

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53 views

Is there a chemical reaction that blocks two cysteines by reacting with a third molecule?

The idea is to block the two cysteines so they can't react in the future. We need the reaction to remove the -SH groups of the two cysteines, or modify them. Also important, the reaction should not ...
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39 views

Pet 28a plasmid is obtained from which type of bacterial strain

I want to ask some question which is very confusing Pet28a is a vector.I want to know which strain of bacteria have pet28a plasmid? E.coli DH5 alpha strain have pet28a plasmid? Please help me .......
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49 views

What would happen if we place denatured DNA in acidic medium?

DNA can be denatured at high temperatures or in alkaline solutions. But DNA can be annealed at low temperatures. I want to ask, could it be annealed in acidic medium?
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Do proteins generally contain phosphorus and sulfur?

I've heard that proteins generally contain six main elements - carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulfur. I know that proteins are made from amino acids. Amino acids are composed of ...
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DNA denaturation and Renaturation

If we denature dsDNA by heating it and then rapidly cooling it then what would happen? I read this question, where it was written that if we were given dsDNA sample which was completely denatured and ...
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34 views

What is a subgenomic promotor? [closed]

I am looking for a good definition of the term "subgenomic promotor". Can someone help me out?
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77 views

Why are the other bases not used for RNA capping and tailing?

Why does the addition of a 5' cap and that of a 3' tail involve guanine and adenine respectively? Why aren't any of the other two bases added to an mRNA to protect its ends or act as a signal to ...
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1answer
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Truncated ORF3a protein of SARS-CoV2! Why? How does it formed?

Across the world so far, we have three truncated ORF3a proteins in SARS-CoV2 in India only. Can you illuminate me how does a protein (here accessory protein of SARS-COV2) generally get such nonsense ...
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1answer
105 views

RNA polymerase Sigma subunit: transcription factor, coenzyme, or what?

Studying prokaryotic transcription, it seems that the α2ββ′ω core enzyme + the sigma (σ) subunit comprise the ‘holoenzyme’ required for prokaryotic transcription. In traditional enzyme nomenclature, ...
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Different Mutations Leading to Same Allele?

Can different mutations lead to the same allele? In my genetics books, I always see alleles referenced as, eg. Aa where A = dominant and a = recessive, but are these strictly binary phenotypes? Since ...
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Are Flippase Recognition Target sites read through during transcription?

I believe it is quite straight forward, but if i have a FRT site following the last exon of a gene (with the stop codon removed), would the transcription factors read through the FRT site and ...
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1answer
31 views

Absence of cytoplasmic Intermediate Filaments in Arthropods

Cytoplasmic intermediate filaments such as vimentins support the architecture of the cell and have been known to aid signaling processes. However, as in this article, it is stated that out of all ...
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Why is the 5′ end of DNA a monophosphate?

According to my textbook: While the 5′ end of a DNA strand is typically a monophosphate, the 5′ end of an RNA molecule is typically a triphosphate. Source: Biology: How Life Works, 3rd Edition How ...
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TMB vs ECL for ELISA: which detection method is more sensitive?

I failed to find a comparison, does anyone know which ELISA detection method is more sensitive of these two: ECL, TMB? Many thanks!
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Walk me through microsatellite markers and PCR

Three polymorph microsatellite markers are used to try and narrow down the location of a disease locus, with the use of PCR with 2 flanks on each side of the actual polymorphic area. The PCR product ...
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1answer
39 views

Why are some parts of an rRNA structure diagram not labelled?

I've been looking at this structure diagram of the 16S rRNA and have been wondering why some parts of the diagrams have labelled base pairs while other parts are just lines and dots. I'm new to this ...
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Why do doctors reccommend vegetable oils in high cholesterol and cardiovascular disease?

As there is high cholesterol in body why the patient need more fats and why the doctors are recommending it Transcribed: Vegetable oils are rich in polyunsaturated fatty acids (PUFA). The fatty acids ...
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409 views

What is the half-life of dNTPs at 95⁰C?

I'm looking for the half-life of dNTPs, either as a whole or broken into individual bases, at 95 degrees C (or similar). A titration would be great if that exists. I can provide more specifics if need ...
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1answer
55 views

Study case of the inheritance system of Oenothera

I've been told some interesting facts about oenothera. Apparently in this species some lineages have been through some translocations and in results to these translocations and in consequence, some ...
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Meaning of “standard reactions” in a DNA extraction procedure description

From a DNA extraction procedure description (an in-house pharma document I'm translating into Russian): Preparation of Standards All the standard reactions should be prepared at least in duplicates. ...
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1answer
50 views

What is the role of pyrophosphatase in RNA polymerization?

In Molecular Cell Biology (8th edition) there's a fragment in chapter 5.2 that says: The energetics of the polymerization reaction strongly favor the addition of ribonucleotides to the growing RNA ...
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Are there any companies that sell Totalseq antibodies that can bind fluorophores conjugated on another antibody?

Are does anyone know of any company which sells Totalseq antibodies that are capable of binding to fluorophores conjugated to another antibody? In this context, I plan to use the Totalseq antibody as ...
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How do the CFTR alleles interact within an individual with Cystic Fibrosis when mutations of different classes are present?

So mutations in CF are classified by the severity of the impact on the production of the CFTR. But an individual may have two different CFTR mutations. I assume that the least severe mutation of the ...
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Delta G and Temperature

I'm now designing primers for PCR. I use Oligo analyzer to check the primer secondary structures. Ex: Delta G: -4.16 kcal/mole Base Pairs: 4 ...
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1answer
29 views

Cellulose structure

In cellulose structure, some beta glucose are inverted. I’ve read that therefore the hydroxyl groups stick on both sides, but aren’t there hydroxyl groups on both sides anyways whether it was inverted ...
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Reverse oxidative phosphorylation?

I noticed that all of the cellular energy production methods that I covered have a fixed ratio of ATP to NAD(P)H out. For example, in the combined process of glycolysis, pyruvate oxidization, and the ...
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Can Stem-loop RT primer bind to the position inside mRNA?

I knew that Stem-loop RT primers bind to the 3' portion of miRNA molecules and then reverse transcriptase to cDNA. But what about mRNA, can it: bind to the 3' portion of mRNA and then reverse? bind ...
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What is the meaning of the word “Ligandable” in “ligandable proteome”?

I see "ligandable proteome", "ligandable proteins" and "ligandable targets" an awful lot. But really I don't know what exactly the word "ligandable" means? Is that it means, for example, "ligandable ...
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Why does the high consumption of saturated fats lead to more risk of cardiovascular diseases and increased cholestrol levels? [duplicate]

People with higher consumption of saturated fats are more at risk of developing cardiovascular diseases as compared to people who mostly consume unsaturated fat. The only structural difference is a ...
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1answer
68 views

qPCR : Cross-contamination while sealing plate

I'm trying to do realtime PCR on a plasmid and I have my positive and negative controls close to each other along with a no-template control. I add 1 ul of my template last into the 96 well plates (on ...
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2answers
36 views

Histone Deacetylase Inhibition

So I am trying to brush up on my knowledge of HATs and HDACs. I am reading the just the 1st paragraph of the background of this study I remember learning that HATs turn things on on, and HDACs turn ...
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2answers
79 views

What exactly happens to hydrogen atoms in step 4 of citric acid cycle?

It seems that there are four hydrogen atoms in alpha-ketoglutarate and one in HS-CoA (not counting the ones in CoA), five in total. Two of them go to NADH and H+, so there should be three atoms in ...
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1answer
34 views

If a cell has two different GPCRs, how does the cell differentiate between the phosphorylation cascade caused by each?

In my biochem course, we learned that GPCR receptors trigger a phosphorylation cascade, with the end result being a large amplification of the signal in the form of cAMP. We never studied any ...
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Doubt related to nerve impulse transmission

Naturally, the extracellular fluid has more sodium ions and the axoplasm has more potassium ions. Since there are more potassium leakage channels than sodium leakage channels on axoplasm, it is more ...
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Why does insertion of transmembrane domains occur in the rough ER?

To elaborate on that question, why in the secretory pathway does the insertion of transmembrane domains into the membrane occur in the rough ER as the protein is translated and threaded across the ER ...
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How is energy stored in the cotransport of molecules down to its electrochemical gradient?

I am talking about symporters and antiporters, that transport usually an amino acid against its concentration gradient while at the same time transport another molecule down its electrochemical or ...
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When purifying plasmid DNA after cloning, do you get endogenous plasmid in addition to your vector of interest?

Since bacteria naturally contain plasmids, when you do a cloning experiment and purify the plasmids at the end, do you get plasmid naturally present in that bacteria in addition to your vector? The ...
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Can DNA rings, i.e. plasmids, form as Möbius strips?

I know that plasmids can be present in a coiled form, which keeps the DNA strands together when they degenerate, by forming catenases. I was wondering, however, whether it has been documented to ...
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Do we consume DNA and proteins of other organisms?

When we eat raw meat, e.g. chicken or fish, we are actually consuming the DNA, proteins etc. which are present in their cells. Wouldn't this affect our cell functions as this DNA might enter our ...
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What causes the overactivity of keratin production and expression in the cells of the nail bed/ nail matrix after some traumata?

What is the cellular mechanism of traumatic(sterile) onychodystrophy(hypertrophy)? I.e one hits his toenail and has it removed twice( once after the first trauma and then again 3 years after the first ...
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Localization of B and T cell

What does localization of B-Cell mean?? "Localization of B and T cell in allergens may not coincide". What does this statement mean? (I have not studied biology since last 8 years and now I am going ...
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Cloning using pET28a and Protein Expression in DH5alpha and BL21

Can someone please direct me to an e-resource or a book that will help a newbie like me learn in depth about Cloning using pET28a and Protein Expression in DH5alpha and BL21. Though I have done ...
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4answers
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Can the activity of a specific gene in a cell artficially be increased?

While there are many gene regulation mechanisms from the cell itself, I was wondering whether it is possible to increase the gene activity in a living cell permanently (so that the protein that it ...
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A little help understanding DNA supercoiling

I am studying molecular biology from Lewin's Genes XII and got confused in the supercoiling topic. Since then I read from several other sources and so far understood the following. However, I can't ...
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43 views

Humic Acid and PCR

Quite a few papers claim humic acid is an inhibitor of PCR reactions. I understand this is true when working with soil microbes, but how does it qualify to be a PCR inhibitor in general (i.e when not ...
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Are there any known consequences of the right-handedness of the DNA double helix?

In this article it is suggested (without evidence) that the right-handedness of DNA may be the cause that "kick[s] off asymmetry in the early embryo [of snails]". On the one hand we know that ...
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Does the brain absorb heme and non-heme iron differently?

I know that for the brain to absorb iron, the iron must first pass through the blood brain barrier. Is this absorption different for heme and nonheme iron?
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Protein half-life regulating gene expression

Are there any instances in real life of protein half-life regulating gene expression? For example, in a cell, Gene A produces a starting population of protein P, after which the expression of the gene ...
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Do proteins contain phosphorous? If its true then how alfred hershey and martha chase used the statement that proteins do not contain phosphorous?

I hv heard about phosphorus that it is a constituent of certain protein, although we know that no amino acids have phosphorus... and if its true then how Alfred hershey and Martha chase experiment got ...
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Eukaryotic DNA polymerase in Leading and Lagging Strand

Different books say a different specifications on which eukaryotic DNA polymerase work in leading strand and which DNA polymerase work in lagging strand. TL,DR: Which one is reality? and if there ...

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