The use of methods from the physical sciences to aid in the study of biological systems.

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Isotropy of sarcomere bands in skeletal muscle cells

As seen under a polarization microscope, the A-Band in skeletal muscle fibres is so named because it is anisotropic in its refractive index which is a characteristic of orderly crystalline structure. ...
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How is saltatory conduction faster than conduction of unmyelinated fibers? [duplicate]

It's always the same explanation that currents are able to "hop" along Ranvier nodes instead of passing continuously along the axon making saltatory conduction more efficient than continuous ...
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67 views

What is the strength of human cornea?

What is the difference of pressure a human eyeball cornea (cornea, lens and other elements separating vitreous body from air) can handle? Or asking differently: what the outside pressure should be to ...
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479 views

How do small animals make loud sounds?

Walking past the park today, I heard a cicada so loud I thought at first it must be some sort of large power tool. How is it that that very small animals like cicadas (crickets, etc.) can make such ...
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Do voltage-gated calcium channels affect neuronal conduction speeds?

We have a hypothesis that a drug may block the voltage-gated calcium channels (VGCC) in annelid worms. We are wondering whether there are any correlations between VGCCs and neuron conduction ...
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What is the exact principle of capillary isotachophoresis?

I know it's a type of capillary electrophoresis, but I don't get how does the separation happen exactly.
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591 views

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, ...
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Why is saltatory conduction faster than continuous conduction?

How does spacing apart sodium and potassium channels allow the action potential to travel faster down the axon? This is the reason always cited for saltatory conduction and myelination, but my mental ...
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Does darker skin color make it easier to live under sun?

I have always thought darker colors absorb more heat from the sun, so if you are wearing a white T-shirt you will be cooler under sun than wearing a darker T-shirt, or a black piece of steel will be ...
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177 views

What is the energy balance of cooking?

If I cook some food, I get apparently several energetic advantages: thermal : the temperature of the food is closer or superior to the temperature of my body or internal organs, so I do not have to ...
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484 views

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 ...
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278 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 ...
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Does coloring affect the perception of depth?

I have a question about the mechanics of human vision which may be as much of a physics question as it is a biology/physiology question. I noticed that if I try to imagine a clear blue daytime sky ...
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How do warm-blooded animals keep their temperatures constant?

Warm blooded animals like us keep their temperature constant irrespective of their surroundings. But how do they do that? Energy should be supplied from the inside. I assume that reactions like making ...
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480 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 ...
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218 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 ...
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891 views

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 ...
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Patch-Clamping Neurons Resources [closed]

Are there any lectures available on Patch-Clamping? Were can I find a mathematical model of Patch-Clamp? (that can be easily implemented in matlab). I have found some step-by-step protocols on ...
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2answers
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How do trees use Adhesion and Cohesion to move water against gravity?

I have an AP Bio class where I have to name 3 properties of water and I chose adhesion and cohesion for one of them. I'm having trouble finding out how exactly trees use adhesion and cohesion to move ...
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109 views

How to quantitatively measure work done by a biological system?

Thermodynamic efficiency can be expressed as the ratio of Work done(W) to Energy invested (Q). Thermodynamic efficiency= W/Q How can one measure work done by a ...
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Is the EC50 of an activating protein for an enzyme a good indicator for the binding affinity Kd?

We work with a membrane protein system where measuring the affinity between the enzyme and the upstream activating protein has been difficult, and when measured in detergent solution, it is almost 100 ...
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289 views

Are Bovine serum albumin, Avidin, Ficoll-70 and Dextran-70 positively charged or negatively charged? [closed]

Bovine serum albumin, Avidin, Ficoll-70 and Dextran-70,are they positively charged or negatively charged ? And which other solvents can be used as a substitute to water for preparing solutions in each ...
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142 views

How to manufacture different sized micelles in nano -scale?

I am trying to answer q5: "How can you manufacture micelles in A) nanometerer -scale B) and in ten nanometer -scale?" My Thinking Observations and some thinking Oil in ...
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140 views

Is there a biophysical causation from local field potential (LFP) to spikes?

Many experiments showed that neurons tend to fire at some phase (usually trough) of local field potential (LFP) oscillations, such as theta or gamma rhythm. LFP is supposedly generated by a population ...
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335 views

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 ...
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Structure of RAP Antibodies (Specifically RAP-5)

[EDIT] - Have just found not one but two papers that address my structure problem. However they concern RAP-1A, so I guess my question is now what is the difference in structure and function of ...
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PDB Mining: Why Do I Find Atoms Less than 1 Angstrom Apart?

I am attempting to find potential Hydrogen bonds between Hydrogen donors and aromatic ring acceptors. I do this by predicting the location of Hydrogens on residues and then calculating how far these ...
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Can a living organism run on electricity?

Each time I'm too lazy too cook I think it'd be cool to be able to just plug myselt into an outlet. Yet I know it is not possible - I need amino acids and a lot of other stuff that electricity can't ...
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What are the trajectories of flying insects?

Many flying insects tend to have very jagged trajectories. For moves of a fruit fly looks like a random walk. Is there any research on the properties of trajectories (e.g. their fractal dimension or ...
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How, on a physical level, does ATP confer energy?

When ATP is used as the energy currency to make, say, reaction X + Y → Z happen, is what happens on a physical level down at the molecular scale that during the reaction ATP + H2O → ADP + Pi ...
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Is “exhaustion” of the Hodgkin-Huxley membrane at constant stimulation a real phenomenon?

I was playing around with a simulation of the Hodgkin-Huxley model using their original parameters for the squid giant axon. By applying a constant stimulation current to the model in resting state, ...