Tagged Questions
The study of the molecular processes underlying life.
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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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29 views
Why dont retroviruses rapidly kill everything
A retrovirus infects a cell and it explodes with thousands of copies in hours. A human has 100 trillion cells. Assuming that these parameters are correct then every human infected with a retrovirus ...
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1answer
20 views
Consensus symbols in multiple sequence alignment
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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1answer
66 views
+50
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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16 views
What is the purpose of chloride ions in the stomach
Why are chloride ions secreted into the gastric pits in addition with hydrogen ions? Why can't the parietal cells simply secrete hydrogen ions for an acidic effect?
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0answers
6 views
microbiology hypo-dermis apparent congestion
Empirical evidence, blisters permeate front of calves, apparent congestion on the hypo dermis, could malnutrition be direct cause, examples of other patients having it?
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12 views
Molecular biology dermis, what is the name given to the border for the hypodermis? [on hold]
Molecular biology dermis, what is the name given to the border for the hypodermis, and what causes it to congest?
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8 views
Why is serum ferritin elevated in Chronic disease anemia?
I've been searching the reason of this but I've been not able to find it.
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1answer
22 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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1answer
34 views
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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1answer
40 views
How to find the amino acid that is bound to a tRNA with the anticodon?
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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10 views
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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1answer
18 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
126 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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1answer
27 views
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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0answers
26 views
I have performed gel electrophoresis without perfoming pcr first. The problem is that no bands have formed not even on the dna ladder
I did my dna extraction and run my gel @ 95volts for 60 minutes. I stained with EtBr but I can't view any bands even though lanes form during the run. Not even ladder bands! Is it because I haven't ...
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1answer
33 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
58 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
17 views
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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1answer
54 views
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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1answer
19 views
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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0answers
17 views
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
28 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
53 views
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
44 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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0answers
8 views
IgE ELISA mouse
i am currently looking for a good method to measure IgE titers in Notch2-KO and Notch2-KI mice after NP-CGG (T-cell dependent antigen) immunization. Can anyone recommend a good ELISA to do this?
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12 views
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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22 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
52 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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0answers
10 views
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
35 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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0answers
17 views
how Eukaryotic cell protect itself from RNAi , silencing mechanism?
RNAi- rna interference
the siRNA can potentially bind to a part of coding rna strand having the complementary bases w.r.t siRNA. So how does cell protect essential coding rna from the RNAi mechanism
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0answers
10 views
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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1answer
24 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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19 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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6 views
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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1answer
26 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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4 views
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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24 views
Is Rh factor an evidence for human evolution from primates?
The Rhesus Factor is an important blood antigen that is found on Rhesus macaque and human being. So is this an evidence for human evolution from monkeys. ???
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2answers
583 views
Is Tyrosine considered hydrophobic or hydrophilic?
I’ve seen Tyrosine classified as a hydrophobic amino acid due to its benzene ring in some textbooks and as hydrophilic due to its hydroxyl group in other textbooks.
How does Tyrosine actually ...
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25 views
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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1answer
21 views
Oxygen in earths atmosphere
If co2 only makes up about 0.04% of the earths atmosphere how do trees and the ocean critters produce oxygen to 10% of the earth's atmosphere?
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0answers
31 views
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
78 views
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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1answer
40 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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1answer
27 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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0answers
31 views
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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1answer
44 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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23 views
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 ...
