The study of the molecular processes of the nucleus and cell function.

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What exactly are genes, DNA and chromosomes. How do they relate to each other and what is their function? [closed]

So I am new to biology and I have been reading, and searching the web, but I couldn't understand the whole framework of a cell. So as I understood: A DNA, is a double chain of Nucleotides (A,T,G,C ...
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48k views

Why do we add salt when precipitating DNA?

All the DNA extraction protocols I have seen involve adding salts to the extraction buffer. What is the purpose of the salts? What happens if they aren't included?
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2answers
71 views

Relationship between DNA strands and mRNA

Does the sense strand or antisense strand of DNA code for the polypeptide product? I'm confused because I know the antisense strand is the template for mRNA but it has anti codons so I do not know how ...
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378 views

Why should phospholipid non-polar tails be “protected” in the membrane bilayer?

lipids are arranged within the membrane with polar head towards the outer side and non polar tails towards inner side, this ensures that the non polar tail is protected from aqueous environment. My ...
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30 views

Question related to pathogen population [closed]

Does only one pathogen of one species enter the host and cause harm to the host or is a certain number of pathogen populations of the same species needed inside the host to disrupt the functionality ...
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1answer
50 views

Can we infect with “bad” genes other organisms? [closed]

We know that some organism's DNA stay with human for life (Herpes) and we also can, i think, design such "gene" that can interact with human's DNA-polymerase very intensive. If we attached this gene ...
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31 views

Quantity of toxin release by pathogen in host

I came across these lines from this paper: Pathogenic microbes exert a broader sphere of influence by releasing a bolus of toxin that can act upon many cells within a given tissue and/or diffuse ...
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134 views

how to quantify toxicity

When going through this link, Table 1, what are the numbers mentioned there? How is one quantifying toxicity?
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41 views

Has a restriction enzyme ever been tagged?

As part of an experiment that I am preparing, it would seem necessary for me to tag a restriction enzyme (HaeIII to be exact) with GFP. I began researching its domains to determine whether to tag the ...
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22 views

Using exogenous genes to reduce the set of essential amino acids?

Various organisms have sets of essential amino acids that they cannot synthesize themselves, but rather that they must obtain from food. Humans have 9 of these amino acids. However, obviously certain ...
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2answers
97 views

How do we find antibiotics?

So the last class of antibiotics were made in 1984 (I think), which makes it appear as though they are hard to find(/design maybe). How is it then they were discovered? Was it by chance? I know some ...
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1answer
30 views

How do normal cell division chance into a tumor forming cell division? [closed]

Or its better to say what happens at molecular level that tumors are formed? I tried normal google search and google books but couldn't find any appropriate explanation. I am trying to understand why ...
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12 views

Similarity between lncRNA and Enhancers

Please read it carefully. Question below is purely based on computational experiments: I have been running an analysis algorithm (pretty new one) on lncRNAs and its showing pretty much the same ...
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45 views

Lifetime of secondary messengers such as Calcium or IP3

Can anyone suggest me literature on the lifetime of secondary messengers such as calcium or IP3? A book would be preferred. What I am specifically looking for is a validation that secondary messengers ...
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1answer
37 views

How to isolate two plasmids from E. Coli strand?

I have an E. coli cell line I use to express a protein using a two plasmid system. One confers AmpR and one KanR. For mutagenesis I would like to separate the plasmids to increase efficiency of the ...
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1answer
78 views

Programs/software to graph biological data [closed]

I am curious about what sort of programs people in my field of academia are using to graph their data. I am a master student in biochemistry, and have more or less only used excel (on rare occasions I ...
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2answers
2k views

Why is the DNA helix anti-parallel? [duplicate]

Why is it that DNA strands are running in anti-parallel fashion? Given the chemical base-pairing, they could have been parallel just as well.
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0answers
24 views

Why are there so many regulatory mechanisms in gene expression? [closed]

first time posting here, apologies if this is a stupid question. I am a layman, so I might be ignorant to some already well-known or obvious concepts in biology. From what I understand, gene ...
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1answer
88 views

How does a protein reach its substrate within the cell?

After a protein has been synthesized and its the final tertiary/quartenary adopted, how does it reach its substrate within the cell and what causes it to interact with it? The transcription factors ...
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1answer
37 views

Why is tRNA called an adaptor molecule?

All I know about adaptor is that it is a device that converts attributes of one electrical device or system to those of an otherwise incompatible device or system. Thank you.
5
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1answer
64 views

Do two compatible tRNA codons bond together?

Can two tRNA with complementary anti-codons link together? For instance UUU with AAA. If not, why not?
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367 views

What is the importance of urea in mass spectrometry?

What is the importance of urea in mass spectrometry? We use 8M urea to FASP our proteins prior to mass spectrometry. What is the significance of using 8M urea? and how does it affect the proteins?
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2answers
64 views

Material recommendation: molecular biology for mathematicians and computer scientists [closed]

I am wondering if there are some introductory learning resources on molecular biology designed specifically for scientists with heavily math-oriented curricula (math/physics/computer science). They ...
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2answers
7k views

What is the difference between transformation and transfection?

What is the difference between transformation and transfection? How do both of these methods work?
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0answers
96 views

Does Cas9 require a nuclear localization signal (NLS) for it to work in a Eukaryote?

I'm trying to establish if it's required to add a NLS to Cas9 when expressed (or transfected) in a Eukaryotic cell. Several papers report using a viral NLS, but is it absolutely necessary? Could ...
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0answers
43 views

Does depolymerisation take place at the minus end of microtubule?

Wikipedia says that Dynamic instability refers to the coexistence of assembly and disassembly at the 'ends' of a microtubule. but Karp's Cell Biology, 7th edition says Dynamic instability ...
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2answers
64 views

What is meant by “Expression” of Non-Coding RNA?

I was having a look at lncRNAdb and its help says: The ENCODE project gene annotation list, GENCODE, has predicted that the human genome contains 14,470 lncRNAs whereas only a small proportion of ...
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1answer
32 views

What do arranging and assigning mean in sequence annotation?

Please could someone explain these lines to me in a simple way These sequences were then arranged based on some overlapping regions present in them. This required generation of overlapping ...
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1answer
55 views

Are there specific non-protein substances that pathogens release into their host?

Reading research articles, I have found out that proteins called effectors get released into the host cell when a pathogen attacks a host. My question is, whether pathogens also release non-protein ...
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1answer
44 views

Plasmolysis vs Flaccidity in cells

When is a cell said to be flaccid and when is it called plasmolysed? So far I found that there is a specific relation to osmosis.
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1answer
134 views

Can bacteria, viruses, and cancer cells be destroyed by resonance?

Radiotherapy has been used to treat cancer. Can the resonances by coordinated electromagnetic waves (and/or other forms of waves), of various frequencies, amplitudes and pulse rates, directed from ...
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36 views

CRISPR Cas9 most updated paper protocol

I am collecting literature to start a new project on CRISPR Cas9 gene editing. I must put together a protocol to start asap. I am intending to use the following paper as guidance: "Genome ...
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1answer
38 views

What is a “noninvasive” biomarker for a disease? [closed]

What is a "noninvasive" biomarker for a disease? I know what a biomarker is, but what makes it noninvasive?
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18 views

Optimum gibson assembly overlap length

Does anyone know the optimum length of overlap your primers should have to your vector for gibson assembly. Most manufacturers say to do at least 20 bp on both side but don't give a maximum. Sometimes ...
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0answers
13 views

SSR Association Mapping [closed]

I do association mapping of SSR with the help of the bioinformatics tool "Tassel v 2.1". Can any one tell me about Ls Mean in GLM. Actually, when I click on "add Ls Mean data" for output the software ...
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2answers
252 views

Why do mitochondria fuse together?

Contrary to all of the textbook images of mitochondria that I have seen over the years, I had just learned that the mitochondria within a cell form a dynamic branching network along microtubule ...
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2answers
55 views

CRISPR/Cas for editing the human genome [closed]

I know, that the CRISP/Cas approach for "cutting" the human genome is not completely suitable if we can't say not suitable at all. Because we have many repeats and this approach can bring to our ...
3
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1answer
48 views

What is a regulable promoter? And how does one regulate it?

I'm reading a patent where they (in S. cerevisae YNP5 strain): downregulate the ERG9 gene by replacing the native ERG9 promoter with the regulable MET3 promoter What's a regulable promoter and ...
3
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2answers
83 views

Is “A” inhibiting “B” and vice-versa, a positive feedback loop?

If product A inhibits the expression of product B, and product B inhibits the expression of product A, is this a positive feedback loop? My thinking was to consider the scenario that A starts off ...
4
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219 views

Randomness in living systems

The point of my question is not to talk about events that are uncontrolled by living organisms. My question is about controlled randomness, or I'd like to say adaptive random process. Process that are ...
4
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1answer
191 views

What do “e” “-” “C” and “E” mean in this output?

I have given an input of this protein sequence: MEPVDPRLEPWKHPGSQPKTACTTCYCKKCCFHCQVCFTTKALGISYGRKKRRQRRRPPQGSQTHQVSLSKQPTSQPRGDPTGPKE from this website along ...
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1answer
28 views

Random Mutagenesis vs Directed Evolution as Strategies to boost expression

Do people use random mutagenesis (say using UV) to generate host variants that have high expression of a metabolite / enzyme? I've seen it mentioned as a strategy but it confuses me as to why. How ...
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2answers
215 views

How can we verify predictions of protein folding in silico?

Currently, there is a lot of research focused on solving the folding patterns of proteins using computers (Folding@Home, https://fold.it/portal/, etc.). The question that I have is: How do you know ...
3
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0answers
59 views

What Chemical Trigger Causes Ectomycorrhiza To Change From Asexual To Sexual?

I want to know the trigger behind the change of asexual to sexual ectomycorrhiza when symbiosis with a tree root is formed. As ectomycorrhiza attaches itself to a root, it forms a relationship wherein ...
3
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1answer
239 views

Where do the H+ ions come from in light reactions?

In the light-dependent reactions of photosynthesis, H+ ions pass to the thylakoid space. Where do these protons come from?
1
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1answer
32 views

Difference between pulse coupling and diffusive coupling In biological oscillators

What are the differences between pulse coupling found among neuron cells and diffusive coupling found in cells that exhibit calcium waves? Moreover, in both methods, is it a strict requirement that ...
3
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1answer
80 views

Does size matter?

As I compare the morphologic differences between mouse models and the human disease for which they are analogous, I have become interested in what difference interspecies size has on molecular ...
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1answer
57 views

Does adding antibiotic after 5-10 mins of innoculation affect the protein yield or growth?

I've asked a lab colleague the same question. She said, it would loosen the bacterial cells in the LB medium and plasmids would come out. Is that true? and why?
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2answers
65 views

Are there proteins that stabilize mRNA:RNA polymerase or mRNA:ribosome complex?

Actinomycetes are known for their ability to produce rich variety of natural products, and particularly, polyketides. Many of the genes that encode the biosynthetic pathways are pretty big, as they ...
3
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1answer
3k views

What's the physical meaning of Svedberg unit?

Sedimentation coefficients, using a centrifuge, are expressed using Svedberg unit (symbol S, sometimes Sv). Wikipedia states that $S = 10^{-13}$ sec but I also saw in a book that actually $S = 10^{-13}...