The use of methods from the physical sciences to aid in the study of biological systems.
Questions tagged [biophysics]
299 questions
17
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1 answer
Quantum mechanics in biology
There is a growing interest in the applications of non-equilibrium quantum dynamics to describe biological processes (I'm not talking here about Penrose's old theories, but new stuff -- quantum coherence in light harvesting, magnetoreception etc.).…
quant_dev
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16
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3 answers
Why don't our cells merge when their phospholipid membranes touch each other?
Membranes of our cells consist of lipid bilayer (with some other components mixed in). Why wouldn't those lipid bilayers glue to each other and make the cells merge? If you suppose that it's due to additional components in the membrane that prevent…
Boris Burkov
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10
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1 answer
Why human cannot stand still in one place?
When a human stands in one place, he cannot stand still but we can see the body slightly swings.
Is this due to the Earth rotation or it has something with biology and muscles relaxations?
I have not been able to find a concrete documents on this…
sandalone
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8
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2 answers
How does spermaceti make a whale float?
In the biochemistry book I'm reading (Box 10-1, Lehninger Principles of Biochemistry), an example is given in whales of how spermaceti (a wax located in the whale head), when at sea level is a liquid, and allows the whale to float due to its…
user4779
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5
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2 answers
Bone conduction . Different from the normal hearing phenomena in humans?
Bone conduction, is it something different from the normal phenomena of listening through the ears. I checked on some literature . Is it so that Bone conduction has very less to do with the ears and more to do with vibrations of the bones in the…
user12448
4
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1 answer
What is the relationship between UV wavelength and penetration depth into human skin?
Some background - Some recent research has strongly suggested that UVA penetration into the skin is far more dangerous than UVB, a very good example is this paper by Agar et al. (2004).
My query is, is there a measure that relates the UV wavelength…
user9474
4
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1 answer
Why is the inside of a cell negatively charged
So my teacher asked: "$[K^+]_i$ (k+ on the inside) is about forty times higher than $[K^+]_o$ (k- on the outside). With so many more positively charged potassium ions inside versus outside, why isn’t the interior of the cell positively charged…
Abid Rizvi
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4
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1 answer
How is green fluorescent protein distributed while inside an organism?
I would like to know a relatively simple thing, but something I wasn't finding the answer to. When fluorescent protein is used in a relatively large, non-transparent animal, like a mouse, or theoretically a dog or a human, how is the protein…
Tom
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3
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1 answer
Why does the DSC peak have a bell shape?
I am studying Differential Scanning Calorimetry (DSC) and am not quite understanding why most proteins have a bell shape when the heat capacity is plotted against the temperature.
Also, I would appreciate if you could provide good sources on this…
Ivan
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3
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Is it possible to biologically convert potential energy to chemical energy?
To lift an object x meters it is necessary to expend, at a minimum, an amount of energy corresponding to the increase in that objects potential energy associated with the increase in height. When putting the object down, returning it to the position…
jarlemag
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How does nitrogen gas partial pressure change when ascending during scuba dive?
Scuba divers suffer decompression illness in which during sudden ascension, gas bubbles form in blood vessels and do not get reabsorbed quickly, leading to various problems including a stroke.
The mechanism is as follows. At high pressure, more…
Kenny Kim
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2
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1 answer
Fraction of channels open at equilibrium
I found the formula for the fraction of channels open at equilibrium for a three-state mechanism (Colquhoun's paper in the microelectrode book http://www.utdallas.edu/~tres/microelectrode/me.html)
k1 and beta are forward rate constants. k-1 and…
user3398600
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2
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1 answer
Health effect of electromagnetic and acoustic waves on brain function
What if any effects are there on brain function from prolonged exposure to electromagnetic or acoustic stimulation?
user31616
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2
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How non-invasive blood glucose concentration measurement work?
Diabetes patients need to conduct the “fingerstick” a few times a day. One of the mechanisms of "fingerstick" is to take small amount of blood sample and put it onto a test strip. The enzyme on the test strip reduces the glucose and the electronics…
aloha
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2
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Muscle force/energy relationship
I found the Hill muscle model, which helps relate the force a muscle can generate to its change in length over time (its "contraction velocity"). Is there a similar model to get an idea of the energy consumed during a contraction as a function of…
Jay Lemmon
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