Questions tagged [molecular-biology]

The study of the molecular processes underlying life.

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2
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1answer
51 views

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 ...
9
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1answer
2k views

What is the role of glucose in plasmid isolation?

My understanding is that glucose is used in the resuspension solution to prevent cells from bursting by maintaining the appropriate osmotic pressure. Why do we even bother doing this? The cells are ...
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0answers
45 views

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 >...
2
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0answers
64 views

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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1answer
30 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.
0
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1answer
40 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 ...
8
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1answer
449 views

How do centrioles auto-locate to opposite sides of cell during mitosis?

I realize that centrioles are made of 9 triplets of microtubulin wound together with a hollow core, and that they are responsible for the configuration of the spindle during mitosis. The spindle ...
2
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3answers
2k views

How does low cysteine conditions affect pheomelanin production?

So we were studying this amino acid called cysteine. Specifically we were studying it's effect on melanin genesis. Our teacher told us how excess of cysteine affects the melanin synthesis by ...
0
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1answer
64 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
32 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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2answers
60 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 :
2
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2answers
64 views

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 ...
2
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0answers
72 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 ...
1
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1answer
110 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....
1
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1answer
18 views

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?
11
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2answers
33k views

Agarose vs agar? Why do DNA gels use agarose only and how do you obtain agarose from agar?

Agar is a relatively cheap substance from red algae. And it contains a saccharide agarose as well as a small amount of pectin. Agar is used for culture plates as is, but for DNA gels a grade of ...
5
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1answer
285 views

What does the “Psi” in “Psi broth” stand for?

When making competent cells I've been using a medium called "Psi broth", which per liter consists of 20 g tryptone, 5 g yeast extract and 5 g MgSO4. Today I got curious about why it's called "psi". Is ...
2
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1answer
187 views

Power consumption of a ATP synthase in Watts

Considering the ATP synthase to be a rotating machine, does anybody know its power consumption and/or power production in Watts? At least roughly, e.g. based on the average chemical energy produced ...
1
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1answer
415 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 ...
0
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1answer
28 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.
5
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1answer
285 views

Compare affinity to potency h1 receptor

This quote from Miller (2004) makes it clear that the affinity of drugs for the H1 receptor does not correlate to sedation: Although both dosage and affinity for histamine H1 receptors play a part ...
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1answer
66 views

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 ...
2
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0answers
53 views

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
40 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 ...
10
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1answer
7k views

Difference in length of Okazaki fragments

The length of Okazaki fragments in the lagging strand is about 100-200 nucleotides in eukaryotes and about 1000-2000 nucleotides in prokaryotes. What (molecular mechanism, enzyme type ) determines ...
0
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1answer
40 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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0answers
25 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 ...
1
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1answer
64 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
81 views

Apolipoprotein B48 and fat storage

Can chylomicrons formed in the intestine, with apolipoprotein B48, transport lipids to adipose cells for storage?
4
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2answers
318 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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0answers
36 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
56 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 ...
2
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2answers
1k views

On which DNA strand is TATA box present?

My book (Snustard and Simmons) mentions that TATA box is present on the non-coding DNA strand but that was for the promoter of mouse thymidine kinase gene. I have tried to find out more information ...
2
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1answer
74 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
291 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 ...
1
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1answer
42 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 ...
1
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1answer
84 views

Gene located on Which strand? Want reference. [duplicate]

Update: Initially my question (below) was appropriately marked as duplicate/overlapping with two other questions; This and this ; among them a specific part of an answer of the second duplicate/...
2
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3answers
638 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 ...
0
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0answers
24 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 ...
0
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1answer
33 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 ...
1
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1answer
83 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 ...
2
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1answer
21 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
83 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. ...
0
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1answer
21 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.
2
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1answer
349 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 ...
2
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1answer
80 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 ...
2
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2answers
71 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. ...
3
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2answers
313 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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2answers
155 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 (...
1
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1answer
86 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 ...