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

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1answer
387 views

How does temperature influence the rate of protein degradation?

For computer modeling purposes, I am looking for some referenced quantitative measurements of the effect(s) of temperature on biochemical reactions. Question In particular, my question is: How does ...
13
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5answers
3k views

Why are some genes dominant over others? What is the mechanism behind it?

If I have a brown eye gene which encodes the protein that is responsible for the brown color and have a blue eye gene as well, what is the reason that my eye color is brown? How does one gene maintain ...
12
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3answers
2k views

Does a man contain all the genes needed to make a woman?

This question is brought on by a Sci Fi novel I am thinking about writing. The plot device involves a colonist in charge of building a population on a new planet who loses his supply of embryos and so ...
8
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2answers
1k views

How to find miRNA binding sites on a specific gene?

I am trying to find miRNAs that bind to the 3'UTR of a specific gene. What is the best way of doing that (that is, with a good scoring analysis that is most commonly used by researchers in this area)? ...
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4answers
2k views

How and where, in the human brain, are memories stored?

Background I am a computer programmer who is fascinated by artificial intelligence and artificial neural networks, and I am becoming more curious about how biological neural networks work. Context ...
9
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2answers
41k views

What is the function of the RNA primer in DNA replication?

During DNA replication, RNA primase puts an RNA primer in the lagging strand. What is the function of this RNA primer? Why can't the enzymes put DNA fragments directly?
30
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4answers
724 views

Why are amino acids in biology homochiral?

Why are nearly all amino acids in organisms left-handed (exception is glycine which has no isomer) when abiotic samples typical have an even mix of left- and right-handed molecules?
8
votes
2answers
281 views

Can forensic DNA analysis be used to generate a visual approximation of a suspect?

In light of the current US supreme court case, I'm curious if enough information can be teased out of a DNA sample to get a "reasonable" approximation of the suspect (never mind the legality). I ...
5
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2answers
198 views

How can E. coli proliferate so rapidly?

The E. coli has a genome with approximately 5×106 bp. The main DNA polymerase involved in its chromosome duplication (DNA pol III , the one with highest processivity) can polymerize ~103 nucleotides ...
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1answer
99 views

Influence of temperature on protein binding and decay rates

For computer modeling purposes, I am looking for some referenced quantitative measurements of the effect(s) of temperature on the dynamic of biochemical reactions. Question In particular, my ...
8
votes
1answer
2k views

why is DNA antiparallel? Can it be parallel?

My biology textbook mentions that DNA is antiparallel and it got me wondering... Can DNA be parallel? What would happen if it was parallel? could DNA still replicate right?
11
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1answer
12k views

Why is ATP the preferred choice for energy carriers?

Why is ATP the most prevalent form of chemical energy storage and utilization in most cells?
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3answers
4k views

Why does replication require primers while transcription does not?

In transcription, there is no need for any primer. I guess the basic mechanism of DNA polymerase & RNA polymerase is the same. So why does replication have the need for a primer?
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2answers
1k views

More variation in proteins than genes. Why?

The Genome of a cell or organism is the same as that of the entire organism. However, the proteome of an organism is much greater than that of each cell (unless the organism is unicellular). How do ...
8
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2answers
223 views

How are antibodies designed?

Antibodies have the ability of recognising highly specific peptide sequences and bind it at their antigen-binding site. This ability is harnessed as a tool in research to purify target structures in ...
6
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2answers
1k views

Alternatives to trypsin for cell detachment?

I have ran out of trypsin and need to passage my cells (immortalized chondrocytes, C28/I2) today or tomorrow. I have been out of town and forgot to order more trypsin. I was wondering if there are ...
4
votes
2answers
169 views

A photosynthesizing mouse?

N. Shubin's Your Inner Fish makes the point several times that there is a lot of functional similarity between some seemingly remote gene cousins. If that needed reinforcing we have the spider-goat, ...
4
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2answers
4k views

On which strand does the promoter sit?

My book keeps giving different indicators as to whether the promoters are on the coding or template strand. It says the -35 region in prokaryotes must be on the coding strand. It also mentions, that ...
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vote
1answer
175 views

Examples of how the presence or absence 2'-hydroxyl groups influence physicochemical properties of DNA and RNA

I know, for instance, that RNA is much more succetible to alkaline hydrolysis than DNA and this difference is determined by the presence of 2'-hydroxyl group in ribose. I have also heard that "DNA is ...
1
vote
1answer
100 views

How is the rate of transcription influenced by temperature?

How is the rate of transcription influenced by temperature? More precisely, I am looking for an article who quantitatively measured the rate of transcription of an "average gene" and show how this ...
22
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1answer
696 views

How, on a physical level, does ATP confer energy?

When ATP is used as the energy currency to make, say, reaction X + Y → Z happen, is what happens on a physical level down at the molecular scale that during the reaction ATP + H2O → ADP + Pi ...
14
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4answers
9k views

Why we have no enzyme to digest cellulose?

As we know, cellulose is the most abundant polysaccharide in nature. Why don't we have any enzyme to digest cellulose?
13
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1answer
230 views

What is the prehistory of amino acids in cells?

As a followup to Why 20 amino acids instead of 64? and What is the smallest number of amino acids required for life?, I am trying to understand the prehistory of amino acids in cells. All living ...
5
votes
2answers
463 views

Evolution of endosymbionts?

Mitochondria and plastids in eukaryotes evolved through a process of endosymbiosis. How does an event like a eukaryote engulfing a bacteria, become a part of the genome? Some of these primitive ...
5
votes
1answer
128 views

enzymes that stabilize DNA loops

As a follow-up of a previous question, I would like to know what enzymes or protein complexes have been used to manipulate DNA samples into stabilizing DNA loops. I have read that cohesin is one of ...
3
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2answers
378 views

How are DNA segments selected in PCR?

I understand that in PCR we're able to amplify only selected portions of the DNA... however despite reading it from multiple sources, I cannot figure out how this selection actually takes place. I ...
19
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3answers
2k views

How long can I store extracted RNA?

If I extract RNA from a (leaf tissue) sample using a one-step phenol:chloroform extraction, how long can those samples be stored at -80°C? And how many times can I defrost and refreeze them before ...
11
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1answer
3k views

How does translational coupling work in prokaryotes?

Today I heard about a phenomenon called "translational coupling", where the translation of one protein influences the translation of another protein. The messenger RNA levels don't seem influenced. ...
9
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1answer
133 views

What are the costs associated with carrying lots of genetic material

What are the costs (if any) associated with carrying lots of genetic material (Big genome size)? energy for copying? raw material for copying? space in the cell? Maintenance cost (matter and ...
7
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1answer
4k views

The effect of the start codon GTG on translation in E. coli

Translation in E. coli is initiated at the start ATG codon, which encodes for the amino acid Methionine (Met). In some cases, the start codon can be GTG, which within the open reading frame (ORF) ...
6
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1answer
5k views

What causes the colors we see in eyes?

Genetics aside, what are the biochemical reasons the different colours of human irises? Also, related, how does eye colour change, particularly in childhood? (example: my eyes used to be blue, ...
5
votes
4answers
686 views

Photosynthesis: What Powers the Splitting of Water?

The splitting of water is an endergonic (non-spontaneous) reaction, and thus would require energy (chemical work to be done) in order to happen. In Photosystem II, an enzyme catalyzes this splitting, ...
4
votes
4answers
194 views

Theoretically, what technique would one use to modify a virus so that it only affected a subset of the population?

I'm writing a novel and i would like to know some of the equipment and techniques involved with modifying a virus. Is it feasible for a virus to be engineered to only affect certain people? It ...
4
votes
1answer
563 views

Effect of single nucleotide deletion or insertion on primer annealing

How is primer annealing, and, consequently, PCR amplification affected by single nucleotide deletion or insertion inside the primer ? Imagine a primer like this: GCGTCATAAAGGGGACGTG (primer) and ...
4
votes
1answer
179 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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2answers
104 views

How do proteins and genes participate in learning?

I am a computer scientist that studies biology and bioinformatics. In the last weeks, I have been trying to study new research directions, and I would like to deepen my knowledge on the role and ...
2
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1answer
98 views

How was Restriction Site of EcoRI sequenced?

The sequence of restriction site of EcoRI - GAATTC was identified in the early 1970s, before Sanger Sequencing was invented.(1977) How was the restriction site of EcoRI sequenced ?
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vote
1answer
190 views

How to relate human metabolic model reactions and cancer drug targets / reactome items?

Trying to find a way to take a cancer drug (from CancerDR, for instance) and infer the metabolic reactions that are affected by it in the Human Metabolic Model. Essentially, I would like to know ...
9
votes
1answer
611 views

How are there alternative initiation codons?

According to wikipedia and the original complete sequence of the K-12 genome, there are multiple non-AUG start codons such as GUG and UUG. How is this possible? I'm particularly curious about the ...
8
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2answers
5k views

why is AUG the initiation codon?

Is there any reason why AUG is the initiation codon ? Why is there a need for an initiation codon ? Can't translation start with different codons?
7
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1answer
100 views

How exactly can dsRNA be introduced to a cell?

Is it just by viruses or are there other means by which it gets into cells, such as plasmid uptake?
7
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1answer
579 views

How fast do different organs turn over cells?

It is said that the human body turns over all cells or molecules in 7 year cycles. This is not quite correct, because there are different organs changing at different speeds. My interest is what is ...
6
votes
1answer
437 views

Why do most organisms have negative supercoiled DNA?

It has been observed that in nature most organisms have negative supercoiled DNA and that few organisms have positive supercoiled DNA. Some of the organisms that have the positive supercoiled DNA live ...
5
votes
2answers
270 views

What is the IC50 exactly?

I am reading the paper "Activity of the bcr-abl kinase inhibitor PD180970" but I don't understand how IC50 works on table 1. Can you tell with simple words and give me an easy example?
5
votes
3answers
144 views

Finding a template/oligo combination for my first PCR experiment

I'm an information technology engineer. I love biology so I research biological topics and have an interest in PCR. That's why I have decided to create a PCR machine. Everything is done now and I ...
4
votes
1answer
47 views

Is HSV-vector-mediated miRNA expression in dorsal root ganglia stable?

My question is on the following article: "Reduction of voltage gated sodium channel protein in DRG by vector mediated miRNA reduces pain in rats with painful diabetic neuropathy" My question is, do ...
4
votes
2answers
484 views

How does optogenetics work?

I am aware of the post here 'Optogenetics - How do microbial opsins work?' however it is a bit too technical for me. I am struggling to understand how the neurons can be genetically engineered to ...
4
votes
1answer
89 views

Influence of temperature on transcription, protein binding and decay rates

I am the kind of biologist who doesn't know much about molecular genetics and about the dynamic of biochemical reactions. Question My question concerns the influence of temperature on the dynamic of ...
4
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0answers
43k views

Does CPH4 exists? [closed]

What is the purpose of CPH-4? Is it well represented in the movie Lucy?
4
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1answer
905 views

Why Isolated, recombinant plasmid DNA without any restriction is often detected in agarose gel electrophoresis as three DNA bands?

I don't understand why three bands are found without any restriction digest. Please answer me as soon as possible. Thank you