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Questions tagged [molecular-biology]

The study of the molecular processes underlying life.

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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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1answer
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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 ...
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0answers
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Fruiting of trees — environmental stimuli and biochemical cascades

My question concerns fruiting of trees in general. However, I live in a tropical country (Philippines) where mango trees are ubiquitous, so I'll use it in stating my question. The question is about >...
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21 views

How the albumin regulates osmotic pressure

Do I understand correctly that: When albumin binds non-water molecules to itself, the concentration of non-water molecules decreases, thus the osmotic pressure decreases; When albumin carries water, ...
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0answers
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Why does M1 RNA together with C5 protein in 100mM Mg(II) fail to cleave tRNA?

Sidney Altman discovered that RNA moeity of RNAse P (M1 RNA) alone is able to perform enzymatic cleavage of ptRNA, which won him the Nobel Prize of Chemistry in 1989. However, when I read the Nobel ...
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2answers
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Chemistry of phosphodiester bond formation by DNA polymerase

As I'm teaching General Biology to my college students, I realized that I don't fully understand how a 3-P nucleotide like ATP is broken down to be incorporated into DNA during replication. How does ...
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1answer
108 views

Is one Short Tandem Repeat (STR) enough for a reliable identification?

The lab simulates the analysis of just one STR in the genome. Would this analysis be sufficient for a reliable identification in real life? If not, explain what could be done using DNA to identify ...
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1answer
26 views

Biology and dna samples to determine parental lineage [closed]

How could you use nuclear and mitochondrial DNA samples run through electrophoresis to determine parental lineage.
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1answer
37 views

How is the timing of gene expression controlled in developing embryo? [closed]

I understand how cell differentiation works in general (gradients of homeobox proteins etc), but how is timing controlled? Why do some genes switch on at a very specific moment of development and then ...
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1answer
23 views

Insertion Confirmation Cloning Strategy

So I am in a bit of a time constraint. Essentially, I inserted a DNA fragment via molecular cloning which contains a unique RE site. I need to confirm whether my colony has or does not have the ...
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What conclusions can I draw about the size, charge, and shape of messenger molecules?

Molecules such as cAMP or Inositol trisphosphate are used in organisms as messenger molecules that make things happen when they are supposed to happen. These molecules are usually big, but not too big,...
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558 views

Why did scientists think humans had 100,000 genes (before the Human Genome Project)?

One of the major results of the Human Genome Project (HGP) was that humans have far fewer separate genes than previously thought. From a 2004 article about the HGP: Francis S. Collins, director of ...
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Is there a good source for detailed molecular/atomic information about plant cells?

Can anyone point me to a good source for understanding the molecular/atomic details for the structure of a plant cell? For each element of the plant cell, I want to know what kinds of molecules/atoms ...
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1answer
30 views

identification of differentially expressed genes in RNA-seq analysis

I am using four different packages (viz. EBSeq, DESeq2, edgeR, LPEseq) for identification of differential genes. Now I am confused whose fold change value should I take for further downstream ...
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2answers
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How do I calulcate the amount of concentrated stock solution to add to get the correct dilution?

For example, how much loading buffer (6X) do I need for my PCR reaction with a volume of 25 μl? What is the general way to calculate it?
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1answer
58 views

How can two biological sequences be anything but homologous?

If we consider homology between two nucleotide sequences as a yes/no answer to whether they have shared a common ancestral sequence, then given that all life share common ancestry and sequences are ...
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1answer
31 views

What does “novel, predicted deleterious, within autozygome” mean in genetics?

I am a medical student and just got involved with a genetic lab and research. I read a lot phrases like: "Although no mutations have been reported in this gene, we think this variant is interesting ...
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1answer
75 views

Is there a reliable source for storage and stability of reducing agents like DTT?

Reading the literature on DTT, one is confronted with a confusing mass of papers; some claim that a 1M solution in water is stable, other papers say it is not. I use the reaction with DTNB to show ...
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2answers
50 views

There are small parts between Genes in an Operon that does not encode for any amino acids. What is the purpose of these parts?

What is the purpose of these parts in the translation process ? Picture to demonstrate below :
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2answers
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How different can the Tm be between 2 primers?

I have a forward primer with Tm 85 degree Celcius. I cannot change this primer. But I have two options for the reverse primer. One with Tm 65 degree Celcius (Annealing at 65 degree Celcius) and ...
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0answers
50 views

How do molecular biologists determine biochemical pathways?

I'm new to this community, so hopefully this is the right place to ask this question. I know my question is really general, but in all of my biology courses we are merely taught the chemical pathways ...
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1answer
43 views

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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1answer
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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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1answer
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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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0answers
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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 ...
2
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1answer
35 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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Why are okazaki fragments of eukaryotes smaller? [duplicate]

Prokaryotes have bigger fragments as compared to eukaryotes. Why so ?
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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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1answer
39 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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1answer
44 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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0answers
25 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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1answer
43 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 ...
4
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2answers
161 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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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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1answer
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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
57 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
131 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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1answer
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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
333 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
32 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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3answers
76 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
73 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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1answer
68 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
20 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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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
183 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 ...