All Questions

5
votes
1answer
598 views

How are lysosome membranes protected from the attack of hydrolases?

Lysosomes are a bit like the suicidal bags of cells. They help to clean cells, have an acidic pH and contain a large number of hydrolyzing enzymes. But why don't these hydrolyzing enzymes attack ...
7
votes
1answer
104 views

What happens when we know that there is something that we forgot but we can't remember what it was?

I think it happens for everyone that sometimes we go to a room and forget why we went there. Is there any research or article on this?
5
votes
3answers
3k views

What are the advantages and disadvantages of using beta-galactosidase compared to luciferase as a reporter gene?

In the University labs, we have used Beta-galactosidase as a reporter gene to quantify the expression initiated by the stress-response promoter in yeast. This was done by exposing one of the two ...
1
vote
1answer
118 views

Is eating salt dangerous for the brain?

I read somewhere that eating a lot of salt will raise blood pressure, which will in turn damage brain tissue. This is because water molecules gather around salt ions, thus making it harder for the ...
1
vote
1answer
86 views

Colonial Cells Demonstrating Cell Specialization

Are there any living examples of cellular colonies demonstrating very primitive cellular specialization? If so, what do we know about how they assimilate? How independent are the individual cells ...
1
vote
1answer
222 views

Would two species of yeast with similar genome sizes have the same number of genes or chromosomes?

Similar organisms generally have similar genome sizes. Given this, would two species of yeast have the same number of genes and chromosomes? Edit: Fixed with thanks to @daniel-standage
4
votes
1answer
147 views

How does ethanol interact with insulin?

I know that ethanol increases insulin secretion--could someone explain why? All I have found till now is experimental data analyses. I am interested in mechanism of alcohol consumption.
4
votes
1answer
162 views

What is ear wax?

A human, at some time in life or the other, must clear the auditory canal. This is usually achieved using soft-cotton buds, or such similar device. Where does this wax come from? What purpose does ...
7
votes
2answers
3k views

Is nicotine toxic to humans?

More specifically, is nicotine in the concentrations that smokers receive when smoking cigarettes toxic? I know that in great enough concentrations it can be toxic (but then, so can just about ...
4
votes
2answers
95 views

Low temperature PCR

We're trying to do emulsion PCR using HA-coated polystyrene beads and we're noticing that the beads are seeing drastic issues with thermal degradation above 90C. As PCR has an unfortunate requirement ...
3
votes
3answers
395 views

What is a good list of unsolved protein structures?

I'm trying to get a list of unique soluble structured proteins that don't have a solved structure. That is, they aren't the usual membrane proteins or some derivative of another protein. Things that ...
3
votes
0answers
92 views

Comparative cost of RNA-seq vs sequencing full length cDNAs

I am in the process of assembling and annotating the genome of a non-model organism, using almost exclusively short read (paired-end Illumina) data. Throughput is one obvious benefit of these data ...
12
votes
1answer
361 views

How are epigenetic marks transmitted during cell division?

As far as I know, this is one of the biggest questions in the epigenetic field: how are the epigenetic marks like histone modifications propagated through cell division? A lot is already known about ...
4
votes
1answer
2k views

3D models of adult male brain in the Blender software? Any open-sourced version for research?

I am trying to find 3D model of brains. I am particularly interested in adult-male -brains in Blender-model. I could find such 3D models of brains for sale here but because I am researching I would ...
7
votes
2answers
267 views

How does the body measure dehydration?

What, physically, does the body do to measure it? I assume it's measured by how how turgid or plasmolysed certain 'sample cells' are, or water concentration in the blood, What is the way they use to ...
2
votes
1answer
60 views

Is it more likely to develop a throat-ache at night?

I have noticed that I rarely develop phlemmy throat-aches in the daytime, but often notice them after I have been sleeping. Is this a recognised phenomenon? Could it be because viruses or bacteria ...
2
votes
1answer
35 views

Is a minimum size/complexity necessary for an organism to exhibit territoriality?

A follow-up to Is territoriality only the domain of the male of a species? I've seen a large butterfly chase a different kind of butterfly around - it may, or may not have been territoriality. Is ...
2
votes
0answers
56 views

Do humans have chemosensors for nutrients or chemicals?

I'm reading about chemoreceptors on Wikipedia, and see that the typical ones are mentioned: taste, smell, CO₂. I would like to learn more about the other kinds of chemoreceptors that humans may ...
3
votes
2answers
2k views

Is there any complex organism that is both autotroph and heterotroph?

Possibility also include "adaptation mode" if such exist. I don't discern whether autotrophic/heterotrophic part play only minor role either.
3
votes
1answer
33 views

Which part of oranges contain fiber?

I think it's pith, but here (non-english country) many chef suggest orange's vascular veins which look "fibrous" and have similar translated word with "fiber" itself. Please enlighten me which?
4
votes
3answers
54 views

Is territoriality only the domain of the male of a species?

Is territoriality (recognizing a geographic location, and challenging another member of the same species and gender) only in the domain of the male of a species? Are there any species out there where ...
8
votes
2answers
477 views

Would exposure to a strong magnetic field have deleterious effect on the human?

This article states of a 25T magnet, ".. If are ever caught in one of these devices, let’s just say you probably won’t live to tell the tale." Is the above statement in order? What effect would ...
4
votes
3answers
157 views

Good book on Origin of Life [closed]

What is a book that goes into reasonable detail (but isn't textbook-level technical) about the origin of earth and in particular the origin of life on earth? Something intended for a broad audience, ...
7
votes
1answer
1k views

How does a single-stranded RNA bind to a double-stranded DNA to form a “triplex structure”?

If you have a single-stranded RNA that is complementary to a double-stranded DNA, how do they interact to form what my prof. calls a "triplex structure"? e.g. ...
4
votes
1answer
139 views

Functionality of vitamin A, Bx, C, D, E, K as used in cosmetics for the skin?

I was wondering if someone can compare the functionality of vitamin A, Bx (x means numbers, such as 1, 2, 3, ...), C, D, E, K in the skin? They are used in cosmetics but what is their actual effect? ...
5
votes
3answers
126 views

Does the entire surface of the earth contain organisms?

Does the entire surface of the earth contain organisms? My teacher mentioned that in some parts of the earth, there aren't any organism. Is this true? Thanks in advance.
1
vote
3answers
199 views

Action Potential Distribution On Synapses

This is a biology+physics question. Since there is no biology section, I am asking here. In brain, when a neuron reaches to threshold value, it fires an action potential. In most graphics, that is ...
6
votes
1answer
812 views

How do neurons form new connections in brain plasticity?

I've been reading about brain plasticity and how the brain can "rewire" itself. One of the things that is not clear to me - how neurons can establish new connections. Does this rewiring mean that ...
3
votes
2answers
1k views

Why is Paracetamol so great?

Every time I get ill (cold, flu etc) I take a couple of these wonderful tablets for up to 4 times a day and I, eventually, get better. What exactly is paracetamol? Why is it so effective and is it ...
7
votes
2answers
184 views

What measures are commonly used for the complexity of an organism?

I'm aware of measures like number of distinct cell types being used as a measurement of complexity in biology, for example in the G-value paradox. But this doesn't really help for unicellular ...
5
votes
1answer
238 views

Are tongues red because they contain blood?

Many animals have red tongues, though not all of them - blue-tongued skinks and giraffes come to mind. Are they red because of the blood (and therefore haemoglobin) in them? It sounds plausible, but ...
6
votes
1answer
799 views

How efficient is the sodium-potassium pump ?

I am reading about transportation of ions in a cell. It is necessary to transport sodium back out and potassium back in, against their electrochemical gradient. This task is carried out by ...
3
votes
1answer
105 views

Cell growth conditions for preparing electrocompetent cells

Usually the protocol for preparing electrocompetent E. coli cells calls for growing the cells at 37deg and 225rpms until they reach OD of 0.3. I was wondering, is there any reason they should grow at ...
2
votes
1answer
114 views

How can I compare rates of evolution for two sets of proteins?

I have a list of candidate proteins as the result of my analysis. I am now trying to find various characteristics that they have in common. One of the things I would like to check is if my candidates ...
1
vote
2answers
235 views

Do any cells change in size or mass as mammals grow?

That is to say, are there cells that, between infancy and adulthood, get larger? Or is all growth done entirely via cell division? I'm wondering if it is safe to assume that the approximate number ...
3
votes
1answer
403 views

Do adipose cells divide in adults?

I have a dim recollection of having heard that when humans gain weight, adipose cells just get larger, rather than dividing. True?
1
vote
1answer
63 views

In a human, what non-germline cells have the highest/lowest mass?

I'm just curious which cells are largest/smallest in the human body other than sperm/ova.
2
votes
1answer
126 views

Histone marks mechanism

I am slightly confused about the mechanisms that makes histone modifications associate with gene expression. That is, H3K36me3 is believed to be present in actively transcribed genes, H3K27me3 in ...
3
votes
3answers
753 views

What makes urine smell acrid?

Occasionally, after someone's been, there is an awful acrid smell lying about long after them. What causes this? The food that they've eaten? Urea less dilute due to dehydration? If it helps I've ...
2
votes
1answer
113 views

Where does an organism store reserves of amino acids?

Where does an organism store reserves of the amino acids it needs to build various proteins it needs -- in the liver ? in the blood ? in every cell ? Thanks
6
votes
1answer
7k views

Will a bone marrow transplant change one's blood type?

Will a bone marrow transplant change one's blood type? Or is the donor blood type matched with the person before transplant?
5
votes
2answers
178 views

How to get smallest subtree containing a set of nodes from BioPhylo?

I'm testing out various phylogenetic libraries in Python. I want to read in a Newick tree, then, given a list of taxa, generate the smallest tree that contains them all. This task is quite simple and ...
6
votes
1answer
80 views

What are the biological mechanisms behind the increase in cancer risk and alcohol consumption?

Alcohol consumption is known to be a risk factor for developing cancer. Compared to obvious causes like tobacco where one is exposed to known carcinogens, I don't see an obvious mechanism by which ...
0
votes
2answers
347 views

Why do living organisms replicate itself or procreate

Why do living organisms spontaneously replicate itself or "procreate" (my understanding is that it does). From a uni-cellular and micro-organism point of view. Is there some sort of stimulant in the ...
4
votes
4answers
1k views

Multiple sequence alignment - how to align everything to 1 gene sequence?

I'm having trouble aligning 3 sequences together - the total gene (~2500bp) and the forward and reverse sequences that are ~1000bp in length. Now I'm using Clustal X2, but the problem is that the ...
4
votes
2answers
668 views

Why is Botulinum toxin the most potent poison known?

Botulinum toxin (trade name Botox) inhibits acetylcholine release in neurons and causes botulism, an acute paralytic disease which leads to nerve degeneration and takes a long time to recover. I've ...
1
vote
1answer
93 views

Interpreting SNP-in-gene associations from GWAS studies

For most SNPs identified in GWAS studies, is the underlying assumption that if it is indeed associated with a phenotype (and lets assume its associated because it affects protein function), that you ...
3
votes
1answer
71 views

Nucleotide frequencies in Kimura's two-parameter model

Here's an excerpt about Kimura's two-parameter model from Felsenstein's Inferring Phylogenies: "The model is symmetrical, and one can immediately see that, after enough time has elapsed, it ...
2
votes
3answers
496 views

Is there such thing as “half-life” of dopamine?

If a dopamine is released at T=0 and binds to receptor D2, what determines the time when the concentration of this neurotransmitter bound to the receptor reaches half of the original concentration? In ...
3
votes
0answers
244 views

Why does vision go blurry after microscope use, and how to prevent it? [closed]

After using a binocular microscope recently for about 20 minutes, my vision went blurry and for an hour or so it was much harder to read small text. This occurs to a (far) lesser extent whenever I use ...

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