6
votes
3answers
16k views

Differences Between Protein Motifs and Protein Domains?

I am in a 300-level molecular biology class and am unclear about this concept and how to delineate motifs versus domains of proteins. Any suggestions would be much obliged.
3
votes
3answers
324 views

Is it possible to make bacteria vulnerable to antibiotics it's resistant to?

Since bacteria becomes resistant to antibiotics after an unfinished course, is it possible to do anything to be able to get treatment with the same antibiotic again, and reverse the resistance in the ...
3
votes
1answer
222 views

Perception of distant lights without glasses

I am fairly short-sighted and wear glasses pretty much all the time. Naively, I would expect that when I take my glasses off, the image I see should look very much the same as as a photograph that's ...
4
votes
1answer
149 views

How do the variable portions of antibody genes look in cells which don't produce antibodies?

There are several families of antibodies found in mammals. They may have two or more antibody domains which contain heavy and light chains. The variable regions of the light and heavy chains genes ...
1
vote
1answer
103 views

When is wing growth in the bat complete and how soon can bats fly after wing growth is complete?

I was reading this paper by Cretekos et al (2008), in which they state that wing development in the bat is not complete until after birth - the wing continues to elongate postnatally. This would ...
4
votes
2answers
176 views

How do you store membrane proteins?

We're producing some membrane proteins and they aren't amenable to freeze thaws even when we add glycerol. The proteins are solubilized in detergent above the cmc so they should be in micelle form in ...
2
votes
1answer
432 views

How exactly does marijuana damage brain cells?

I've heard that THC can cause permanent damage to brain cells. I've also heard this reffered to anti drug propaganda. Another theory i've read is that temporary effects reduce intelligence but long ...
6
votes
1answer
81 views

What controls the southern range of willows?

Many willows (Salix spp.) grow in northern states but do not grow in southern states, for example Salix viminalis. What mechanisms control the southern range of temperate hardwoods such as willow? Is ...
1
vote
1answer
295 views

Cyanobacterial photosynthetic oxygen yield

I am somehow not convinced that biotic factors are solely responsible for creating 21% of atmosphere (around 40 million moles of oxygen). There may be additional issues here. Since cyanobacteria ...
0
votes
0answers
55 views

Western blotting of lung samples [duplicate]

I have been working on lung samples to perform western blotting. I have two related questions about this: I get very nonspecific results: at times nothing at all, at times it glows on membrane but ...
1
vote
1answer
160 views

How do axon terminals report to the soma?

It is important to bear in mind that the distance between a neuron's axon terminal and its soma can be extensive, up to about 1m in the human body. The fastest transport along the axon is 400mm/day ...
3
votes
3answers
2k views

How did this spider evolve to mimic exactly a human face and arms?

So I came across something terribly amazing today, that is, a video showing this species of peacock-spider, that literally, transforms into a human face waving his arms about. What could have ...
3
votes
1answer
189 views

What is range of the number of individual organelles in cells

What is the range of the number of individual organelles in a cell? I am not a biologist but I understand that there's one nucleus and sometimes lots of mitochondria, so I am after the total number. ...
2
votes
1answer
514 views

Strange behavior of a DNA gel

I ran a PCR product of ~300 bp on a 2% TAE-agarose gel for 30 minutes. I used Sybr-safe as a DNA stain. Voltage was 80V. When I imaged the gel, the DNA on the bottom half of the gel, including the ...
6
votes
2answers
5k views

Why does plucking nose hair cause tears in the eyes?

It's not a particularly sad or painful thing to pluck a few nose hairs, but it's common for the tear ducts to wet up when doing this. I would like to know the physiological reason for the ...
1
vote
1answer
342 views

Parthenogenesis in Bees

Parthenogenesis is defined as: "A type of asexual reproduction in which egg develops without fertilization to form a new individual." If parthenogenesis takes place in bees, a drone or male bee is ...
1
vote
1answer
213 views

Why does contracting the iris allow less intense light to go in?

The iris contracts automatically in the presence of bright light. This makes a flashlight appear bright in darkness, but outside in daylight you can't even see it's light. The iris is changing your ...
2
votes
2answers
797 views

How prevalent is Taq polymerase in adding 3' A overhangs to the PCR product?

I am conducting a mutagenesis on a gene in vivo of which I need to ligate into an expression vector. The primers I have designed overlap restriction sites of which I plan to use to ligate into the ...
0
votes
1answer
524 views

Definition of Dye- Reduction Test?

Can some one give a simple explanation or definition on what a dye-reduction test is.
5
votes
1answer
394 views

Are there eukaryotes without introns?

This question on the function of introns in eukaryotic genes made me think: I know that more basal organisms have smaller introns and fewer alternatively spliced exons compared to mammals. But are ...
6
votes
3answers
991 views

What percentage of protein isoforms have different functions?

I am looking for studies on how many protein isoforms have different functions, preferably in human. We know that a great many, if not most, of human genes are alternatively spliced and that many ...
2
votes
1answer
160 views

EGFR, sialylation, and cancer progression

EGFR (epidermal growth factor receptor) has been intensively studied in cancer and treatments have been developed to inhibit EGFR signaling. Sialylation of EGFR is known to block dimerization and ...
1
vote
1answer
539 views

Why does the hydrolysis of ATP increasing entropy increase the Phosphoryl-­‐transfer Potential?

I am currently taking a biology class. I do not understand this concept. I understand that the electrostatic repulsion of the negative charges, resonance stabilization and hydration stabilization all ...
11
votes
1answer
859 views

What is the gas inside a Capsicum pepper, and how does it get there?

Every time I make fajitas, I cut into bell and chili peppers and notice how hollow they are. I always think to myself: what is the gas inside this pepper, and how does it get there? Perhaps Capsicum ...
3
votes
1answer
54 views

In which month should I map maritime vegetation?

I'm studying habitat use by Brent Goose in the UK, a species that feeds on maritime vegetation. It's main food types are Zostera sp., Ruppia sp., Ulva / Enteromorpha sp. and Puccinellia sp. I plan to ...
0
votes
1answer
34 views

How Common are Paraneoplastic Syndromes in Cancer Patients?

I recall reading around one in four cancer patients will suffer a paraneoplastic syndrome during the course of their illness but I can't find where I read this and I can't find any reliable sources to ...
4
votes
1answer
942 views

Why Do Nerve Signals Get Crossed?

First off, I don't know if this is a normal healthy thing to occur. There have been many times where I have an itch on say my arm and I scratch it, only to feel the scratching elsewhere on my body. I ...
4
votes
3answers
217 views

Is it technically possible to make someone see something when their eyes are closed?

I'm writing a little article and need any information about how human vision works and latest technologies and discoveries around. Actually its not a professional article. Its for a group of my ...
0
votes
1answer
111 views

Which Enzymes Catalyse the Deacetylation of Drugs in the Human Body?

If you would like more specifics seeing how I realise that this question is very broad and may be difficult to answer in general then hopefully the following will help you out: I am particularly ...
3
votes
1answer
298 views

How might gene clusters like the lac operon evolve?

The obvious answer for a gene cluster is gene duplication and mutation of one or both genes. But the genes in the lac operon seem not be so functionally/structurally similar (as compared to the Hox ...
3
votes
1answer
127 views

205 nm UV-Vis readings

Typically we determine the concentration of proteins using a 280 nm reading. However, it is reasonable to use 205 nm. I was curious about the effectiveness of this method.
0
votes
1answer
313 views

Least painful way to die

There is a lot of talk about inhumane treatment of animals and how we don't kill them in the proper way. I wonder how much research is done on this subject. What is the overall least painful way for ...
0
votes
1answer
828 views

DNA gel extraction: chemical contaminants

I am performing a gel extraction to purify DNA after a double digest with EcoRI and BamHI. After the gel extraction I need to complete a ligation step before bacterial transformation. The problem I ...
2
votes
0answers
51 views

Onset of Autophagy

Fasting and Intermittent Fasting (IF) have been proven to start autophagy (cellular self-digestion). How long does the average man and woman have to wait for autophagy to begin? Does diet prior to ...
6
votes
1answer
199 views

If life is discovered on another planet, will it likely be classified using the current domain/kingdom/phylum system?

This may be a stupid question showing my lack of understanding of taxonomy, but I was wondering if the current classification system we use contains broad enough categories to include new life forms, ...
1
vote
1answer
52 views

How are geneticists able to isolate gene functions?

As an example, this Scientific American article describes a known area in the dog genome that metabolizes carbohydrates. How is it that researchers are able to determine specific functions such as ...
0
votes
1answer
690 views

What's the difference between life expectancy of cigarette smoker and general population?

Some say that smoking cigarettes will shorten lifespan. By how many years is the lifespan of a typical smoker shortened? What are the common cause(s) of death among smokers? Are there any known ...
1
vote
1answer
470 views

What is the brightest color a light source that only emits blue frequency light can achieve?

Let's say there is a luminous light bulb that only emits blue light, and you (or a camera if you prefer) look at it from a close distance. Will the maximum brightness perceived not have any "white" to ...
1
vote
1answer
103 views

How might IVF (and related technologies) alter epigenetic marks?

I was reading up on KCNQ1, which encodes a voltage-gated potassium channel, and I discovered that it happens to be only maternally expressed. This is regulated by KCNQ1OT1, a non-coding RNA, which is ...
1
vote
2answers
215 views

Effect of zero selection (pressure) on the population health

Evolution naturally produces better features: stronger muscles, teeth and minds. Killing the weakest, evolution wipes defective genes out of populations. The mutations are necessary for advance. ...
1
vote
1answer
50 views

What does “Psychomodulatory” mean in the context of potentially psychoactive drugs?

What does "Psychomodulatory" mean in the context of potentially psychoactive drugs? That is, in this journal article http://www.sciencedirect.com/science/article/pii/S0028390812001931 in the ...
2
votes
0answers
101 views

Is there a Pharmacology Textbook that Satisfies the Conditions listed in the Body of this Question?

The conditions are: As extensive and explanatory as Goodman and Gilman's The Pharmacological Basis of Therapeutics, Twelfth Edition With additional extensive and thoroughly explanatory information ...
4
votes
1answer
2k views

What is immunopanning (vs. immunoprecipitation and FACS)?

I had never heard the term before today. From what I can tell, it's using antibodies to purify a cell population of interest. I would appreciate more details, especially in how it differs from ...
6
votes
1answer
241 views

What is the best way to express two proteins in a mammalian cell?

I have two proteins and I will be preparing a vector with both genes for stable transfection. Each protein will have their own promoter and I will use piggyBac vector to insert a single cassette with ...
2
votes
1answer
133 views

Expanding the SETI initiative to seek intelligent data within DNA sequences?

I've recently read a couple articles dealing with long term data storage, and DNA was suggested as one of the prime candidates for long term storage of digital data additionally, there is this article ...
6
votes
1answer
4k views

What causes adenosine build up in the brain when awake?

Adenosine is an important hormone in sleep regulation. It is postulated that when a person is awake, there is a build up of adenosine in the brain, which inhibits the neurons in the brain, and ...
3
votes
0answers
33 views

A program for cell motility assessment with a batch process function?

Cell motility assessment is a branch of experimental biology or medical science. One example could be an assessment of treatment effects on sperm motility of an animal. The standard procedure involves ...
1
vote
1answer
151 views

What is background binding?

I'm reading a journal article about mitochondrial protein import and it mentions that one of the mutant proteins tested showed background binding with another protein. What the heck is background ...
11
votes
3answers
2k views

How can homosexuality evolve despite natural selection?

I would imagine that the answer to this question would be population control, especially since even if one sibling is homosexual this does not necessarily mean that the other siblings will be too.
5
votes
1answer
556 views

What causes humans to be sleepy?

Is there a hormone or group of hormones that regulates when we feel sleepy late at night, or in the morning? Or is sleepiness caused by some other non-hormonal mechanism? (e.g. pure psychological, ...

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