5
votes
1answer
1k views

Why are pili more common in Gram negative bacteria than in Gram positive?

Although pili have been observed in some species of Gram positive bacteria, the preliminary research that I have done indicates that pili are significantly more common in Gram negative bacteria. Is ...
3
votes
3answers
171 views

Super-resolution imaging in vivo

Are there any microscopy modalities or techniques for in vivo imaging at higher resolutions than the diffraction limit? I was looking at this list: Super resolution microscopy, but they don't talk ...
1
vote
1answer
75 views

Is it possible to give a person an allergic reaction in a very specific place?

Can I give a person an allergic reaction at a very specific spot in a tissue? And if so, how accurate can i get?
1
vote
2answers
194 views

Why does throat 'burn' when you've got a common cold?

Apart from pain when swallowing, there's also a persistent feeling of throat 'burning' in the same area. What causes it and why does it feel that way?
4
votes
2answers
223 views

Hershey and Chase experiment

http://www.youtube.com/watch?v=3QJ4CjFsflA This is a link to Hershey and Chase experiment. According to this experiment, we conclude that DNA is the genetic material. But how do we conclude that DNA ...
4
votes
1answer
147 views

Can the immune system stop plasmodium from being active?

Suppose a female Anopheles infected with Plasmodium bites someone and transmits Plasmodium to their body. Can that person's immune system be strong enough that it can kill the Plasmodium before it ...
2
votes
0answers
122 views

Resuspending Cells from a filter plate

My experiment involves pulling down cells on to a filter plate for a variety of assays. However, I want to ensure that my cells are alive so I am trying to resuspend them so that I can do an accurate ...
2
votes
1answer
201 views

Is there an “Adam and Eve” for each new trait during (not just human) evolution? [duplicate]

Do new beneficial mutation evolve simultaneously and independently with several individuals of the same specie or only with one specimen who then transfers it to all of the specie? In other words, ...
5
votes
1answer
170 views

What is a Mitochondrial Eve and Y-chromosomal Adam

I've read this question: What kind of event would cause the current Mitochondrial Eve to be replaced by a new one? And the values in Wikipedia about Mitochondrial Eve and Y-chromosomal Adam and I am ...
3
votes
1answer
106 views

Do serotonergic (5-HT2A-mediated) psychedelics elicit stimulant effects?

I know that 5-HT2A partial agonism is the key mechanism of action of serotonergic psychedelics but I also know that some research (e.g. the selective (no activity on any other known receptor sites) ...
1
vote
1answer
156 views

Does the NMDA antagonist, Memantine that's used to prevent Excitotoxicity cause brain damage?

Does the NMDA antagonist, Memantine that's used to prevent excitotoxicity in Alzheimer's disease (AD) and Dementia with Lewy Bodies (DLB) cause brain damage? I know that in rodents NMDA antagonists ...
1
vote
0answers
19 views

Which Receptors are involved in Psychedelia/Psychosis?

Which receptors are involved in Psychedelia/Psychosis? I know that the 5-HT2A, 5-HT3, D2, κ-opioid and NMDA receptors are likely involved in psychosis.
0
votes
2answers
357 views

Which range are the Therapeutic Indices of Currently-Prescribed Benzodiazepines in?

A compound's therapeutic index is defined as: $$TI = \frac{LD_{50}}{ED_{50}}$$ What range are the therapeutic indices of benzodiazepines in? For the method of administration I would prefer ...
10
votes
2answers
510 views

Could hydrogen replace oxygen in cellular respiration?

I was wondering what oxygen actually does in the body. I have seen a few answers to other questions that involve the electron chain and I am really not sure what that is. So I was wondering what ...
2
votes
2answers
41 views

Studying changes in DNA for causes of cancer

First of all let me say that I'm not into Biology myself... but I have a question for those of you who are. From what I've read, cancer is caused by 'faulty' DNA that behaves abnormally. Mutations ...
6
votes
1answer
94 views

Proteins that are strongly overproduced in E. coli and S. cerevisiae?

I'm looking for some pointers to proteins that produce at really gigantic levels in E. coli and yeast (S. cerevisiae). Can anyone point to some champion proteins? Even in inclusion bodies and non ...
8
votes
2answers
388 views

Why is blood pressure higher the more distal an artery is?

Why is blood pressure generally higher in more distal arteries?
7
votes
1answer
508 views

Which sex has higher variance of reproductive rate in modern societies - male or females?

Who has a more varied reproduction rate in modern western societies - men or women? The average rate is the same of course, but I wonder which sex have higher variance - higher variance means that ...
4
votes
1answer
189 views

In the diffraction pattern of a protein crystal what exactly determines the intensities of the spots?

What I have read is that the contents of the unit cell affect the intensities, but how? I am also unclear on why you need to know the symmetry of the unit cell, what is that used for? I understand ...
1
vote
1answer
150 views

What is the biochemical reason for mental fatigue?

Is it known exactly why the brain needs sleep? What's dropping low / going high when we experience mental fatigue? I can see why low glucose could result in mental fatigue, are other reasons known?
1
vote
1answer
116 views

How do circulating androgens contribute to higher rates of hirsuteness in some women?

I was reading up on ethnic groups in which the women are naturally more hirsute (such as South Asian women) in the context of evolving standards of beauty. I came across this statement on a forum: ...
2
votes
1answer
53 views

Trigger allergic reaction in non-allergic people?

Is there a proven way to trigger an allergic or allergic-like reaction in non-allergic people? I have wondered if this is possible, since allergies are basically just a form hypersensitivity - so ...
9
votes
2answers
6k views

What is the difference between SOLiD, 454, and Illumina next-gen sequencing?

I've started teaching myself about next-generation sequencing in preparation for a new job, and I'm wondering what the main differences are between the 454, SOLiD, and Illumina/Solexa machines, in ...
3
votes
2answers
225 views

Short-term Lamarckism in asexual single cell organisms

I was reading through the Karr et al. (2012) whole-cell computational model. One of the things they did was to induce single-gene disruptions in their model. They observed several to be fatal, but: ...
3
votes
2answers
2k views

Simple diffusion of lipid-soluble molecules through phospholipid bilayer — does anything get “stuck” in transit?

It's a pretty elementary concept, and when I first learned of it I don't think I had the foundations to even think of such a question, but I found myself the other day thinking about the amphipathic ...
4
votes
2answers
216 views

Question about equilibrium potential formula

My biology book says, that the equilibrium potential for an ion with a charge of +1 is: $$E_{ion}= 62mV \biggl(\log\frac{[ion]_{outside}}{[ion]_{inside}}\biggr)$$ Where does the 62 mV come from? How ...
4
votes
1answer
41 views

position of cell penetrating peptide

I'd like to add a cell penetrating peptide to my custom peptide (30aa). Can I just add it to the end of the peptide sequence or does it have to be positioned on an outward facing external chain?
10
votes
2answers
169 views

protocol for pulldown of DNA breakpoints?

Is there any method to do pulldown enrichment of DNA breakpoints from a cell? I have found this paper reporting a method to enrich for the DNA single-strand breakpoints from meiotic recombination ...
5
votes
2answers
53 views

Prostaglandin F2-alpha production in men

I am trying to find information on Prostaglandin F2-alpha, specificaly production in men. Could somebody explain how this prostaglandin is produced? What types of cells are producing it, production ...
1
vote
1answer
393 views

What is the advantage of circular genomes for bacteria and linear genomes for other organisms?

Bacterial are a great group of organisms. They have circular genomes and never went toward linear genomes while other organisms show the opposite strategy and don't have circular genomes (disregarding ...
3
votes
1answer
158 views

Does an allergic reaction kill body cells?

I have wondered what actually happens in an allergic reaction that causes the symptoms such as pain, rash etc. Is it possible that the human body actually kills its own cells in the process?
6
votes
2answers
740 views

Why is absorbance at 280 nm for protein solution going up when I measure repeatedly?

I have been measuring my protein solutions' concentrations by diluting them in water 20 fold with a final volume of 100 uL and then measuring the absorbances of these solutions in 96 well plates with ...
-1
votes
3answers
151 views

A question regarding evolution

I'm not a biologist so bear with me. I know that the DNA molecule carries extremely large amounts of information. If the process of evolution is driven by completely random process .I think about it ...
9
votes
1answer
156 views

Systems identification in small neural network

When analyzing data from cortex, we often try to understand what each neuron does in terms of its inputs from other neurons - a specific kind of a systems identification strategy. Most current ...
3
votes
2answers
456 views

What are gram negative and positive bacteria?

I've just finished a course of double antibiotics for Helicobacter pylori in my stomach. I looked up H. pylori and found that it was a gram-negative bacterium. I looked up gram-negative and didn't ...
1
vote
0answers
55 views

Why did animals evolve genders? [duplicate]

The majority of animals have two genders, and both are needed in reproduction. It seems like it would be more advantageous for creatures to be hermaphrodites, since they could mate with any member of ...
1
vote
0answers
15 views

Which classes of drugs (filed by their pharmacology) induce a release of beta-endorphin?

Which classes of drugs (filed by their binding sites) induce a release of $\beta$-endorphin? I know of agonists of the nAChRs and 5-HT1A and ethanol. Are there any others? Please cite journal ...
1
vote
0answers
283 views

How do Opioids Stimulate a Histamine Release?

Histamine is a neurotransmitter that also has peripheral functions such as the regulation of gastric acid secretions, allergic responses, etc. I know that opioids stimulate a release of histamine but ...
0
votes
2answers
48 views

Manipulating Gut flora in vivo

I am tasked with designing an in vivo experiment in humans that requires manipulating the gut flora in one sample group to gauge its effect. Please suggest ways of doing this besides administering ...
1
vote
0answers
31 views

Which mixed opioid agonist/antagonist are approved for Human Use in Europe and/or the USA?

Which mixed opioid agonist/antagonist are approved for Human Use in Europe and/or the USA? I know of: Buprenorphine Butorphanol Nalbuphine Pentazocine Are there any others? If so I would like you ...
10
votes
3answers
341 views

Athletes: nature vs. nurture?

Having watched a lot of olympians the last few weeks, I was struck by how many of them have actually spent their wholes lives/careers training for their one event (be in running a marathon, or ...
2
votes
0answers
31 views

Do sulfate reducing bacteria help during the formation of the mineral dolomite in low temperature environments?

Do sulfate reducing bacteria help during the formation of the mineral dolomite in low temperature environments? Wikipedia says The actual role of bacteria in the low-temperature formation of ...
2
votes
3answers
2k views

Do cold blooded animals generate any heat?

In explaining energy and work to an 8 year-old I said that all conversion of energy generates heat as a by-product. For example, cars generate heat in their engines and running generates heat in our ...
1
vote
1answer
107 views

Interlocus Contest Evolution means suicide?

I was reading Matt Ridley's "Genome" book. I am trying to understand the Interlocus Contest Evolution in his X-Y chapter. I do not understand why the X and Y chromosome would want to kill each other. ...
3
votes
2answers
199 views

What software is there available for Quantitative structure–activity relationship (QSAR) pharmacological studies?

QSAR modelling in pharmacology basically hangs on using mathematical modelling to approximate the effects different molecules will have on various pharmacological targets. I would like to know what ...
4
votes
0answers
72 views

What are the mechanisms that cause bananas to ripen? How is or isn't it related to the banana peel ripening? [closed]

So recently our commercial kitchen got some bunches of bananas with a curious feature. On the inside they were firm and delicious (no jokes, please), on the outside they looked incredibly sickly. ...
4
votes
1answer
732 views

Why is second pKa value of phosphoric acid different across different sources?

Am I missing something very fundamental here for phosphoric acid's second pKa value? I check the Wikipedia page and these are the values: (1) 2.148, (2) 7.198, (3) 12.377 Then I check Sigma-Aldrich ...
6
votes
2answers
433 views

What is the relationship between migraines and histamine?

A family member suffers from migraines so I have been reading a little around the subject. There seem to be any number of "triggers", but I have seen mention several times of the role of histamine ...
4
votes
3answers
1k views

Is the theory of evolution being disproved by bats?

For some species the Darwin's theory evolution makes perfect sense. I can easily imagine how, for example, the giraffe has evolved to its current appearance: the natural selection was favoring ...
7
votes
2answers
163 views

Is it possible for parasitic wasp to alter the behaviour of it's host after emerging from it?

I know that parasitic wasp larvae could live for a long time inside their alive host (eg. caterpillar), but I always thought that they kill the host when they eventually get out of it. But once I've ...

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