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Questions tagged [molecular-biology]

The study of the molecular processes underlying life.

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What is (roughly) the net charge of the DNA in an average human cell?

I was wondering about what general range for the net charge of DNA in human cells is in Coulombs. I imagine that kind of thing would be hard to measure but could be approximately calculated/estimated....
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What is the reason behind studying seroprevalence of a disease?

Scientific literature on viral disease, specifically ones like Zika and Dengue, contains seroprevalence data. What is the reason behind understanding seroprevalence?
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25 views

Thousands of Reporters Integrated in Parallel (TRIP) barcodes

Has anyone worked with constructing barcodes for TRIP? How does constructing of barcodes work in general? I don't seem to be able to grasp the basics of constructing these barcodes.
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Is there any liquid that can replace water?

I understand this is a little futuristic but water freezes and damages cell causing cryostasis yet a reality. Is there any liquid that can be added to the blood synthetic or not that either plants and ...
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Molecular Docking Enzyme Inhibitor Biosensor?

I had some task to study Molecular Docking relations with Biosensor and I am really new with this discipline (beginner). I am docking C60 with Glucose Oxidase and my question is: what would happen if ...
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1answer
37 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 1ul of my template last into the 96 well plates (on ...
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22 views

Why is CLL B-Cell leukemia t(12;21) more responsive to chemotherapy?

Chronic Lympoid Leukemia targeting B-Cell (with the particular translocation mutation on chromosome 12 and 21) is known to be more responsive to chemotherapy. Is there a known molecular mechanism for ...
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54 views

What is the source of the fat in adipose tissue?

I have heard the opinion that all of it comes from de novo lipogenesis of carbohydrates, but I'm skeptical. Is there evidence either way - either that dietary fat definitely gets stored in the adipose ...
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58 views

Apolipoprotein B48 and fat storage

Can chylomicrons formed in the intestine, with apolipoprotein B48, transport lipids to adipose cells for storage?
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35 views

What Does Transcription Factor E25 Activate When a Cell is Transitioning from G1 to S

Cyclin D/ CDK4 phosphorylates Rb allowing for the activation of transcription factor E25 during the G1 phase of the cell cycle. Supposedly, this transcription factor then activates as set of genes ...
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46 views

Consensus symbols in multiple sequence alignment [closed]

I was using multAlin for multiple aligning a set of sequences. The output I and came across included the following documentation (English corrected): Consensus symbols: ! is any of IV $ is any ...
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2answers
218 views

How does transcription end?

In rho-dependent termination in prokaryotes, how does RNA polymerase “know” that it has reached the end of a gene and that it has to stop so that the rho-factor can bind mRNA’s rut site? Is there a ...
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36 views

How do PrP mutations lead to prion disease?

My understanding is: The PrP gene in human cells is expressed as both PrP-c (normal protein) and PrP-sc (prion disease protein). This happens post transcriptionally, that is, the normal and the ...
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When in Ampicillin degraded (gone) in liquid TB-media? Concerns about selectivity

Question: Specifically regarding Ampicillin; When growing cells in TB (terrific broth) for protein expression - when should I expect the ampicillin to be gone due to degradation by b-lactamases? (and ...
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208 views

How to find the amino acid that is bound to a tRNA with the anticodon? [closed]

What amino acid is bound to a tRNA with the following anticodon: $5^{\prime}$ A U G $3^{\prime}$ The answer is Histidine. What amino acid is attached to the tRNA with the ...
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Mechanism Behind Viral Capsid Breakdown When In Cell

In the example of a retrovirus, after the lipid bilayer fuses with the membrane of the cell, the capsid dissolves releasing the viral content. What is the mechanism behind the capsid dissolving? I ...
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40 views

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

In this paper, 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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3answers
462 views

Can the central dogma work in reverse?

Theoretically, is it possible to obtain the original gene from the protein’s amino acid sequence as its “template”, as in, the reverse of how gene’s codons were “templates” for the amino acid sequence ...
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Why doesn't my rtPCR reaction work?

I am doing a rtPCR to detect the watermelon mosaic virus (WMV). My set of primers are: WMV primer forward: 5'-TNGARAATTTGGATGYAGG-3' WMV primer reverse: 5'-CTGCGGTGGACCCATACC -3' both of which at ...
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3answers
81 views

Biological validation of computationally determined gene-gene interaction

How can a computationally determined three-way gene interaction be biologically validated? What kind of assays or tests must be performed using cell/tissue-based and/or mouse models to prove that the ...
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1answer
80 views

About The Selfish Gene Book - How Replicators Molecules forms duplicates?

I was reading The Selfish Gene. In the 2nd chapter - "Replicators" I read: Think of the replicator as a mold or template. Imagine it as a large molecule consisting of a complex chain of various ...
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1answer
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HLA typing between siblings to identify a genetic disorder

If a patient suffering from a complex array of signs and symptoms for a disease and is having an 8/8 loci match with his sister who suffers no such symptoms can you conclude that the disease is an X-...
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which of these fields will cure aging? [closed]

life extension is expected to happen as a result of breakthroughs in tissue rejuvenation, stem cells, regenerative medicine, molecular repair, gene therapy, pharmaceuticals, and organ replacement. ...
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mRNA Sequencing Basepair from Polyadenylation Site?

I was wondering how many basepairs are usually sequenced with mRNA/cDNA illumina methods from upstream of the polyedenlation site? Thanks.
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How to calculate the Marker Index(MI) for a dominant marker such as RAPD and ISSR?

I am working in the genetic diversity analysis of a plant species and have used RAPD and ISSR markers. After scoring the data in a binary matrix, I am trying to find the marker index of the primers. I ...
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1answer
289 views

Pyruvate oxidation - where did the hydrogen come from?

As shown in the diagram above, NAD+ is reduced and becomes NADH by gaining two electrons Now, where did the hydrogen come from? In the diagram, pyruvate has 3 hydrogen, but it still has 3 hydrogen ...
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1answer
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What proportion of proteins require chaperone-assisted folding?

I am new to the field of biochemistry (I am a chemist, actually). I have long known the process of folding as the process that leads to the minimum energy conformation of a protein. Now, I am ...
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2answers
60 views

What dictates which protein to synthesize at a given time?

I understand how DNA is replicated and how it directs the synthesis of proteins from amino acids through RNA polymerase, RNA and ribosomes. Now I want to understand how it works in the big picture. ...
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Question Concerning Plasmid Transplant

Upon reading a report today, I discovered a interesting technic of plasmid transformation. Triparental Conjugation, a bacterial conjugation including three parts , a conjugative plasmid, a donor cell ,...
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26 views

Finding whether a DNA strand contains duplicate sequences

I know that using Hybridization Probes one can check if a nucleotide sequence complementary to the probe is present in a DNA strand by marking it and then verifying whether it attached the strand or ...
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2answers
249 views

number of chromatids seen in karyotype

The karyotype is performed on a cell whose cycle has been stopped in metaphase or pro metaphase, using colchicine or by other means. In the textbooks I read that during the S phase each of the 46 ...
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Structure of microscopic chromosomes

What is the characteristic of the microscopic structure of chromosomes? As an example, what are some types of chromosomes?
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2answers
170 views

Is it ok to keep primers at 4 degrees?

I reconstitute my primers in nuclease free water ( no sterilised) this morning and I forgot them at 4 degrees, acording to the instructions, they should be storage at -20 after the reconstitution. I ...
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Increasing my PCR efficiency to be able to better visualise my bands

I run an electrophoresis in agarose gel and my expected bands are extremely week, is even hard to see them. It looks I need to increase my PCR efficiency. I have read about a Hot start setp, which ...
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61 views

In centrioles, what type of fibers connect the triplet microtubules?

In a centriole, each "arm" (a triplet microtubule) is attached from its A-tubule to the C-tubule of the adjacent arm. What is the type of fiber that connects each arm ("connecting fibrils" in the ...
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Functional Difference between the Distal Promoter and Enhancer Region

According to the Wikipedia article on eukaryotic promoter regions, the distal promoter is: Anything further upstream (but not an enhancer or other regulatory region whose influence is positional/...
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314 views

Are microtubules in centrioles helical, like they are when in isolation?

Microtubules tend to be of a helical structure, do microtubules in centrioles also have a helical structure? The centriole is composed of nine circularly arranged triplet microtubules, one complete ...
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Experimental methods to demonstrate coupling of GPCRs [closed]

How would you experimentally demonstrate receptor coupling through each of the G proteins, Gs and/or Gi?
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31 views

how many spores are needed to “infect” a wall?

There's cardboard box in my room that used to be in another room that had mold all over the walls. and it still smells moldy ,it probably means the air in my room is polluted with mold spores.(right?) ...
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What is an acceptable qPCR efficiency when adjust using the Pfaffl equation?

I have efficiencies of 76% and 85%. THis is clearly below what is normally acceptable. But the pfaffl equation corrects this, doesnt it? However is it acceptable to publish this data?
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Is tyrosine hydrophobic or hydrophilic?

I’ve seen tyrosine classified as a hydrophobic amino acid due to its aromatic ring in some textbooks and as hydrophilic due to its hydroxyl group in other textbooks. How does tyrosine actually ...
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how can I decrease noise in my staining and increase the signal?

I am trying to stain LN sections (from mice), for Madcam-1 using Madcam purified ab as primary and anti-Rat Cy3 ab as secondary. I have tried many times, very few times worked Ok but most of the times ...
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39 views

Oxygen in the earth’s atmosphere

If CO2 only makes up about 0.04% of the earth’s atmosphere how do trees and organisms in the ocean produce oxygen to 10% of the earth’s atmosphere?
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Isolation of Intact Granules from Mast Cells

How to isolate intact granules from mast cells without using sucrose and percoll?
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2answers
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Protein - one polypeptide molecule or a collection of molecules?

I'm struggling a bit in Bio 111 with confusing terminology between the terms "chain" and "molecule". I understand the primary structure of a protein is a chain of amino acids connected by peptide (...
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48 views

What is meant by “a codon codes for an amino acid”? [closed]

What is meant by "a codon codes for an amino acid"? Does it mean in order to build that amino acid you must combine those three nucleotides? Does it mean anything more than provides the instructions ...
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86 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 can I get stronger staining for my lymph node sections

I am using the same protocol and same antibodies that the literature says but still I cannot get good staining for my lymph node sections, I tried to change the fixation method and I am using now ...
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315 views

Genotypes of gametes produced by an F1 individual?

I have an urgent question as I have an exam tomorrow. I was skimming some past exam papers and one question came up which has me completely confused. A cross was made between a pure breeding ...
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pcr troubleshoot for toxoplasma with GRA6

I did pcr for Toxoplasma genotyping with GRA6 gene. my primer sequences were forward 5-GTAGCGTGCTTGTTGGCGAC-3 reverse 5-TACAAGACATAGAGTGCCCC-3. PCR was done in a 25μl reaction mixture. I used 10pmol ...