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Questions tagged [molecular-biology]

The study of the molecular processes underlying life.

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How does hydrophilic and/or hydrophobic components of polysaccharides influence their 3 dimensional conformation?

It is my understanding that polysaccharides are insoluble in water. Does this mean they are hydrophobic? Beyond being insoluble in water how does this affect their 3D structure? Thanks!
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How does CRISPR/Cas9 compare to plasmid injection for editing new genes into cells?

I've heard that both of these techniques can be used to add new genes to cells, so I'm curious as to how they compare, e.g.: can plasmids be used in eukaryotes like CRISPR? are plasmids kept after ...
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do platelets cytoplasm contains DNA?

I'm a 12th-grade student and I have an entrance exam this year. I have a question in biology. I would appreciate you if you help me <3 as we thoroughly know platelets are multiple pieces of a big ...
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How is Saccharomyces cerevisiae grown on acetate and ammonium able to produce TCA intermediates?

I am working with a metabolic model of Saccharomyces cerevisiae and I am studying its growth on acetate and ammonia. I am performing Flux Balance Analysis to compute the growth rate and then I am ...
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How to rid MRSA on my lower calves that have been getting worse for over a year now [closed]

MRSA in lower right extremity and partial MRSA in lower left extremity/calves/Edema related from lung cancer operation 4 years prior.
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3answers
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How can I set micropipette volume with decimal separators, for example 109.5 in p200?

And how can I set: 150.1 in p200 871.3 in p1000 840.5 in p1000?
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RNA Molecule folding

For a Single Stranded RNA Molecule : A) Adenine Content Always Equals to Thymine Content B) Cytosine content Equals to Guanine content C) Adenine content Always Equal to Uracil D) Guanine content ...
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1answer
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Size constraints on CRISPR guide RNA

I had a quick questions on the size limitations of a CRISPR guide. More specifically on the shorter end. Can I make a guide that is say 7-10bp and still have an active complex? I transfect using an ...
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1answer
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Improving DNA quality and yield from stool samples

I prepared genomic DNA from pig stools but the concentration was very low — about 3~4 ng/µl, when I measured it using nanodrop. The A260/A280 and ...
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1answer
25 views

Why pellet and resuspend E. coli for plasmid prep

For maxipreps, cant you just add all the stuff that would be in P1 (RNase A, EDTA) then just add P2? Because if we pellet cells then resuspend theres got to be a reason, right? Is it slats and other ...
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1answer
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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 ...
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1answer
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Could deutrium oxide be used to make organic compounds with Deutrium instead of hydrogen? [closed]

I am wondering for prokaryotes if Deutrium Oxide could be made into Deutrium Glucose or other biological compounds with Deutrium.
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1answer
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How to identify whether something is in linkage disequilibrium?

If the following loci indicated the presence of an SNP in flu strains, is Locus 2 and Locus 3, which are located 10 bp apart in linkage disequilibrium? "When alleles and molecular markers are ...
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Why are higher doses of atropine required to produce central effects?

Reason given in my book is restricted entry into the brain..is it something to do with the chemisty?
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1answer
27 views

Ligation without purifying insert

I am planning to insert a 45 bp sequence in a vector. After restricting my insert to create compatible sticky ends, I am finding no way to clean it up. Is there any way for cleaning this fragment ...
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1answer
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Gene vs Protein homology

I am trying to find homologs for some proteins and I am wondering if it is better to find it by comparing the proteins or the coding genes or either is fine.
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1answer
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Why do we use different micropipette tips for different volumes? [closed]

Isn’t it easier to use a 1000 µl micropipette tip for all volumes? I don’t understand why there are different tips for smaller volumes. Does it affect the accuracy of the pipette for very small (<...
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1answer
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Melting point of animal fat and plant fat

I notice in daily life that animal fat typically has a higher melting point than plant fat does. I wonder the reason why this happens. What exactly contributes to this difference? Is it because of the ...
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Formation of annular structures in carbohydrates

In Lehninger's Principles of Biochemistry, David L. Nelson and Michael M. Cox state that monosoccharides with more than four carbon atoms often have cyclic structures (pyrannoses and furans) and ...
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1answer
37 views

When muscles contract is the process similar to how non-newtonian fluids react?

I'm trying to understand how muscles contraction/tension works but getting loss in on the cellular level. From my understanding, when muscle tissue need to contract, the cells are flooded with calcium?...
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How to take precise/low number of cells from cell lysate? [closed]

I would like to know that how can we take low or precise number of cells from a cell lysate? (without using any protein quantification assay). Let say, If I have a cell line having cell density 5x10^...
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1answer
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Does *E. coli Dh5 Alpha* strain has the ability to degrade polyethylene?

Does E. coli Dh5 Alpha strain has the ability to degrade polyethylene? What are the bacteria that can be used as a control in the research of polyethylene degradation?
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Multiplex real-time PCR on different sized amplicons

I'm planning to do multiplexing on my qPCRs for 3 different amplicons with widely varying sizes (180 bp, 200 bp and 370 bp) Is there going to be a significant bias in the quantification due to the ...
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What M9 stands for

Can anyone tell me what M9 stands for in M9 medium? I have tried googling but I still cannot find it.
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1answer
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Antigen molecular mimicry

Let us consider a situation in which the body is attacked by a microbe, and the microbe is captured by the immune system for recognition of surface antigens. The surface antigen recognized mimics one ...
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1answer
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Is studying chemical and physical properties of chemical substances that make up organisms really a task of molecular biology?

I have read in a high school textbook that (translated into English by myself): "Branch of science that concerns itself with studying chemical and physical properties of substances that make up ...
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1answer
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What is the difference between a signal peptide and a transit peptide?

From what I know, the two names are used interchangeably and I haven't found any resource which says otherwise either. Is there at all any difference, is there a transit peptide that is not a signal ...
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Can we spike with a different enzyme to a SYBR Green Master Mix?

I followed the standard SYBR Green Protocol for doing a qPCR. For which I used 10 uL of 1X SYBR Green Master Mix Forward Primer and Reverse Primer (each at a final conc. = 8.5 uM) Template (unknown ...
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1answer
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Barr body. How does it work? [duplicate]

Barr's body is a spiral X chromosome. If I'm not mistaken, one random chromosome (a healthy woman) is inactivated in each cell. Which X chromosome is inactivated in a given cell is random. I've heard ...
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1answer
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Why is Turner's syndrome a problem?

So Turner's syndrome is a chromosomal defect where one of the X chromosomes is missing. For more details visit the [Wikipedia page] (https://en.m.wikipedia.org/wiki/Turner_syndrome). But I don't ...
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1answer
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Design rules for DNA linkers

I want to use double stranded DNA linkers to physically bind two "things" together, by grafting ssDNA on each one of them and using DNA hybridization as the locking mechanism. I do not expect the ...
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1answer
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Why don't the heads of phospholipid bilayers repel hydrophobic molecules?

What I Think I Know: Hydrophilic and hydrophobic things repel each other. Since the cell membrane contains hydrophobic tails, it is difficult for hydrophilic molecules to pass through the cell ...
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1answer
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What would “N” and “V” stand for in DNA barcoding?

I'm currently looking protocol for PAT-seq, and when it talks about the barcoding that's utilized, the documentation mentions there being an "N" and "NN" in the sequence, as well as a "V". For example:...
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2answers
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Are redundant codons used in translation?

I am learning about redundancy in genetics and I came across this statement in my textbook: more than one codon for an amino acid means that some codons are redundant - the process of protein ...
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1answer
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Will DNA nanostructures be useful for medical applications?

There is a lot of work being done on developing small nanomechanical structures and even small nanomechanical actuators built with DNA. I have heard researchers motivate this research with claims ...
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How does Ran GDP get from the cytoplasm back to the nucleus following nuclear import and export?

I understand that in Ran-dependent nuclear import Ran GTP binds importin in the nucleus, and after diffusing through the nuclear pore complex Ran GTP is hydrolyzed to Ran GDP and releases importin. ...
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1answer
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What is trans-complementation?

Is trans-complementation a complementation of transgenes? The crystal structure reveals a trans-complementation mechanism whereby an incomplete immunoglobulin-like domain assimilates an isoform-...
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4answers
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What is the longest-lasting protein in a human body?

Protein life times are, on average, not particularly long, on a human life timescale. I was wondering, how old is the oldest protein in a human body? Just to clarify, I mean in terms of seconds/...
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1answer
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Why are there inverted repeats in response elements?

The following picture shows an inverted repeat sequence in a response element. Response element sequences for glucocorticoids, estrogen, and thyroid hormone show that they all contain inverse repeats. ...
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1answer
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Hydrophobic interactions in the helix-turn-helix

This slide states that the second helix works to stablize the configuration of the two helixes via hydrophobic interactions. What exactly is this hydrophobic interaction? In other words, what ...
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1answer
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Protein electrophoresis

Three proteins A, B and C of equal molecular weight are being investigated in a study. They contain six, four and four cysteine residues respectively. Only Proteins A and B were treated with β-...
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2answers
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Name of dsRNA (or dsDNA) where all strands are identical

What is the name of dsRNA (or DNA) where all component strands are identical (i.e. where the complex consists of multiple copies of the same ssRNA)? Example: 2 identical ssRNAs forming a dsRNA ...
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Does every protein encoding gene necessarily have a transcription factor?

For instance, transcription factor gene A is responsible for activating gene B that encodes protein 1. However, it is possible for genes like gene B to encode proteins without having transcription ...
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2answers
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What makes/breaks the hydrogen bonds between DNA and RNA during transcription?

So I know that RNA polymerase catalyzes the phosphodiester bonds that hold the sugar backbones of a growing mRNA molecule together during transcription. However, I'm less sure about the hydrogen bonds ...
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What's the difference between beta thalassemia minor and beta thalassemia intermediate?

I mean beta thalassemia minor is caused by inserting one abnormal allele while beta thalassemia intermediate is when the person has at least one B+ allele. Is beta thalassemia intermedia a type of ...
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Questions to protein folding

I have some questions regarding the process of Protein folding. These are the following: Are there existing Protein folding processes, where only a few seconds after completed folding a Protein ...
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1answer
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Does the deletion of Chromosome 20 cause immunity against prion disease?

I was reading recently about prion disease and it caught my attention that a normal prion protein is coded n chromosome 20, therefore, in order for an infectious prion protein to attack, there must be ...
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1answer
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What does it mean to use DMSO as a dissolvant in biology experiemnts?

In many biology publications, I saw that dimethyl sulfoxide (DMSO) is used to dissolve drugs. However, the cell-based assays are still performed in water-based medium such as RPMI or PBS. My ...
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3answers
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You need DNA to make RNA, and RNA to make DNA, so they had to come into existence at the same time?

A statement I recently read: 'Evolution is debunked and gives no basis for morality. Natural Selection throws away info, it does not add. You need DNA to make RNA, and RNA to make DNA, so they had to ...
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How to find idea for essay [closed]

I'm studying microbiology in Iran The university that I'm studying in doesn't provide that much help in research areas and we don't get to research or write essays that much ,while I'm trying to write ...