6
votes
1answer
93 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 ...
2
votes
1answer
71 views

What causes tree lines?

There is an area of where there is a distinct line of only trees on one side and only shrubs on the other (right next to each other). What could cause this? My attempt: I said there could be a ...
4
votes
2answers
214 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 ...
6
votes
3answers
609 views

How to map the Gene name to its Gene Symbol?

I am learning in Gene data lately so I apologize for the silly questions in advance. I read a paper for a cancer on human which found some important genes. For example, the paper listed one of genes ...
8
votes
3answers
256 views

What kind of event would cause the current Mitochondrial Eve to be replaced by a new one?

Apparently all living humans are matrilineal descendants of a single woman who lived 200.000 years ago. She is called Mitochondrial Eve. But at the time she lived there was a different matrilineal ...
3
votes
1answer
110 views

High protein turnover rate and protease inhibitors?

I work with mice, and I want to see what happens to some specific proteins in the mouse brain after IL-1b injection (intracerebroventricular). I have a problem: when I measure the mRNA and protein ...
6
votes
2answers
15k 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?
7
votes
2answers
827 views

Bacterial cell lysis - what solution to use?

I am trying to determine how quickly detergents act on bacterial cells (cell lysis). I would like to compare some detergents at difference concentrations for bacteriolytic activity. I don’t care about ...
4
votes
1answer
112 views

Are there oligocellular organisms in nature and, if so, what are they like?

I'd think protozoans can be oligocellular, but I haven't found any examples, and I'm curious to know what is the minimum number of cells an organism can have other than a single cell.
2
votes
1answer
70 views

Experiments in vitro vs those with dead organisms and fixated tissue

Does the term in vitro necessarily imply that the organism/organs/cells of study are dead? If not, is there an alternative latin term to refer to studies of dead biological matter ? (e.g. in ...
9
votes
3answers
338 views

What vegetation would thrive in the Martian atmosphere?

Most plants require carbon dioxide for their photosynthesis, which Mars has in overabundance. Would atmosphere composition (let's ignore temperatures for the purpose of this question) of Mars allow ...
3
votes
1answer
131 views

What to look for when buying a light microscope?

I am a science lover and want to buy a microscope to explore things around me. Like studying cell structures, microorganisms, blood and plants. It would be great if there is way to photograph slides. ...
9
votes
4answers
2k views

Does the DNA sequence of a butterfly match that of the caterpillar it used to be?

Just had this thought occur to me. If one were to take a DNA sample(or is it RNA?) of a caterpillar before it became a chrysalis, and attempt to match the sample against one taken after the chrysalis ...
9
votes
1answer
88 views

Vaccination and population dynamics of an epidemic

I'm trying to figure out how should a vaccination model be built to correlate with population density, and I'm having problems to understand meanings of the results I receive when I apply theory on ...
6
votes
2answers
2k views

Gene & Protein nomenclature: N-Myc, c-Myc, et. al

Can someone explain (or point me to an explanation of) exactly what is meant by all the different symbols I see used for writing genes and proteins? I think I know that for genes, we use an italic ...
3
votes
2answers
992 views

What is the evolutionary rationale for palm sweating?

Sweaty palms seems to be a reaction to stress, anxiety, etc. For our forest-inhabiting primate ancestors sweaty palms could cause unwanted side-effects such as slipping off tree branches under ...
6
votes
1answer
119 views

Why does getting certain chemicals in cuts hurt?

More specifically, shampoo. What are the mechanics of detecting a noxious chemical stimulus in terms of which receptors recognise what, how do they do it, and how is this information relayed to the ...
14
votes
4answers
857 views

Why does the cold make us sick?

From the moment we learn to communicate, we always get told, whether by our parents, or our teachers, or by anyone else, to avoid the cold, or to put a jacket on to avoid catching a cold, to dry our ...
4
votes
2answers
127 views

Are all known germs benign in small enough quantities? i.e. Why do we wash our hands?

We know that we wash our hands because germs can get into our body through the nose, the mouth, the eyes, cuts, etc. But I doubt we can completely clean our hands of germs every time we wash them, ...
3
votes
1answer
121 views

Can compounds be predicted from Polyketide synthases gene clusters?

I've seen a few talks on the subject. From a gene cluster, there is some decent ability to determine which domains contribute to certain functional groups in the final metabolites. It sounds like this ...
1
vote
1answer
8k views

Difference between Appendix and the Cecum?

What's the difference between an appendix and a cecum, and what are their functions?
3
votes
1answer
134 views

Eyelids interconnected?

I've seen a patient who had a Vitrectomy (eye surgery) done on a single eye manifest massive swelling on both eyelids. That seems like having my left hand swell after punching a wall with my right ...
2
votes
1answer
79 views

Can animals that rely heavily on sonar sense colour?

Apparently there're species around as rely heavily on sonar to sense the world around them. E.g. Bat, Dolphin, Whale ... The humans, and other terrestrial beings in a lighted world are capable of ...
1
vote
0answers
116 views

Can dry air make a person more prone to catching a cold?

I'm interested if there is a correlation between room air humidity and risk of catching a cold.
7
votes
1answer
5k views

How do prokaryotes perform cellular respiration without membrane-bound organelles?

In order to survive, prokaryotes such as bacteria need to produce energy from food such as glucose. In eukaryotic cells, respiration is performed by mitochondria, but prokaryotic cells do not have ...
2
votes
1answer
219 views

Insulin and monoclonal antibody production

When producing insulin, the gene for its production is inserted into the plasmid of a bacterium that is allowed to replicate freely. Why can't the same thing be done with antibodies (as I understand ...
3
votes
1answer
125 views

What is the length of anaerobic biodigestion stages?

I have built an experimental portable batch biodigester to process organic garbage. A 50L drum filled half with garbage, half with water and with some cow dung added for inoculation, is connected from ...
7
votes
3answers
3k views

Can a human smell through the ears?

The title does, prima facie, appear absurd. Performing a swallowing action whilst pinching the nostrils shut gives the impression of listening through a bucket filled with water around the head; ...
3
votes
2answers
2k views

What is the inlet/outlet speed of air going in/out of our mouth during inhalation/exhalation

During inhalation, your alveoli expand, creating a pressure difference between the atmosphereic pressure and our lung sacks and therefore air will flow into the repspiratory airways. I am trying to ...
10
votes
1answer
104 views

When running a gel, what could cause a standard to run “faster” than usual?

We are running a gel on the products of a restriction digest to determine the size of an insert. We know the vector backbone size should be ~2.9kb; however, the standard appears to be running too ...
11
votes
3answers
1k views

Where does the 'C' in exhaled CO2 mostly come from?

When a human being exhales $CO_2$, what is, by the numbers, the main source of carbon atoms exiting the body in this way? I mean what class of cells, or which tissues are the biggest on a pie chart of ...
5
votes
1answer
97 views

Structures of cyclodextrin complexed with small ligands

For some structural study I am looking for cyclodextrin strucutures (in 3D format such as pdb, mol2, etc) complexed with small molecule ligands, such as cholesterol and even smaller. Right now I could ...
3
votes
1answer
77 views

What mechanisms do animals living in groups (herds, packs, swarms) have against spreading contagious diseases?

While for example a wolf pack provides protection to a sick wolf, increasing its chance of survival, there is a risk of infecting other members of the pack, decreasing their total chance of survival. ...
8
votes
2answers
427 views

Do memories have mass?

If it were possible to live forever, would our brains grow infinitely with the number of memories that we store? Or would we remove old memories as we create new ones?
3
votes
2answers
567 views

Does finite rate of increase depend on mortality of individuals in a population?

As written in my lecture handouts, there two main factors in the Geometric Growth Model of populations: $R_{0}$ is the expected lifetime reproductive output. This way, for unicellulars, for example, ...
4
votes
1answer
194 views

Is the amount of phosphoric acid added to colas enough to disrupt the function of the kidney over the long term?

Both Coca-Cola and Pepsi add phosphoric acid $H_3PO_4$ to their colas to give them a signature "bite". The kidneys use a phosphoric acid/dihydrogen phosphate/hydrogen phosphate homeostasis as one ...
4
votes
1answer
134 views

Will a completely removed cat whisker grow back?

I just accidentally pulled out, while playing, my cat's whisker entirely, follicle and all. I feel terribly as I know she is a kitten and whiskers are rooted deep in a place rich in nerves. I'm ...
12
votes
1answer
1k views

How much energy does human body fat contain?

I have been reading the Wikipedia article about food energy, but as I'm not a biologist, I don't really understand it properly, so I came here to ask you guys. My question is: If a human body needs X ...
5
votes
1answer
94 views

What types of archaea have been found in animals?

I am curious as to the species or "types" of archaea that have been found to reside within animals symbiotically. One of the only ones I can think of off the top of my head are methanogens, which live ...
8
votes
2answers
639 views

How much weight/volume do microbes occupy within the human body?

Microorganisms constitute the bulk of all the biomass on Earth. I weighed myself yesterday, and wondered how much less I would weigh if I were completely free of bacteria and microbes, inside and out. ...
5
votes
1answer
506 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
100 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
2k 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
115 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
82 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
196 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
137 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
156 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
2k 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
90 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 ...

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