Questions tagged [membrane]
26 questions
7
votes
2 answers
How do membrane proteins find their target locations?
The question might be asked for any kind of "bound" proteins, but I'd like to restrict it to membrane proteins.
Assuming membrane proteins (or their main parts) don't (or aren't) build in situ but at some distance of the membrane, I wonder by which…
Hans-Peter Stricker
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6
votes
1 answer
Do free computer programs exist that can simulate drug permeability in bacterial membranes?
I am currently trying to make derivatives of a molecule in hopes of making it more permeable to bacterial membranes. I wanted to know whether there are any bacterial membrane simulating programs where I can dock my molecule and see its predicted…
5
votes
1 answer
Rate of Diffusion Through Cellulose Membrane
From what I understand, the larger the molecular size, the slower the rate of diffusion and vice versa. However, after doing a lab (similar to this one) about diffusion through a cellulose membrane, my instructor said that despite substances having…
bioguy
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5
votes
1 answer
How do nuclear membranes form during Telophase of Mitosis/Meiosis?
During Telophase, homologous chromosome pairs reach the poles of the cell with the help of microtubules. From there, nuclear membranes form around each new set of chromosomes.
My confusion originates from a single question: How did these nuclear…
puradox
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4
votes
1 answer
Do cell membranes have more phospholipids in one layer than in the other?
Assuming the cell membrane to have a spherical shape, geometry tells us that the area of the inner leaflet is smaller than the area of the outer due to the difference in radius between them. Does this mean that the inner layer has fewer…
BioE
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4
votes
2 answers
Where in the cochlea are frequencies below 200 Hz detected?
I understand that different frequencies are detected in different positions along the cochlea.
I'm also aware that the range of human hearing is roughly between 20 Hz and 20 kHz.
However, looking at the below diagram, the lowest frequency, at the…
Hoff
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3
votes
1 answer
What is the basis of the endocochlear potential?
I am learning about the endocochlear potential. According to different sources, the ionic composition of perilymph is about as follows (in mM): 150 Na+, 4-5 K+, 1.2 Ca2+, 1 Mg2+, 120 Cl−, and 20 HCO3−; and that of endolymph is 1 Na+, 157 K+, 0.02…
Jimmy
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3
votes
0 answers
Movement of few ion during changes in membrane potential
My question is very simple: why is it sufficient for a very few ions (such as 1 in 100000 K+) to move across the membrane to generate a remarkable variation in the membrane potential (like a change of 100mV) ??
I took the examples from my university…
Ginevra B
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3
votes
0 answers
Can the Donnan effect be reversed so phospholipids follow ions?
I know that there are flipases and flopases that facilitate this sort of thing, but I'm curious about other possible influences. Can the Donnan effect be reversed so that phospholipids follow ions? For example, calcium efflux from cells causes it to…
Jasand Pruski
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2
votes
1 answer
Plasma Membrane Proteins and Cytoskeletal Attachment
Regarding membrane protein functions, which of the following
statements is CORRECT?
a. Membrane proteins are responsible for both cell to cell recognition
and cell anchoring and are stabilised by linking through to the
microtubulele…
Stefan
- 41
- 3
2
votes
0 answers
Potential between endolymph/cytoplasm and endolymph/perilymph
I am studying for an exam and there is something I can't seem to understand. My textbook says that the endolymph contains 150mM potassium, 2mM Na+ and 130mM Cl-. The perilymph contains 5mM potassium, 140mM Na+ and 110mM Cl-. "Thus" the electric…
Marina
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2
votes
1 answer
When does DIFFUSION occur and not OSMOSIS, and the otherwise?
For example, I do know that red blood cells have both the Na+/Cl- co-transporter and Aquaporin (water channel) that allows both Na/Cl and water molecules to pass through. But why in biology textbooks they imply that osmosis occurs instead of the…
franciscaxyz
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1
vote
1 answer
Where are the ATP synthases synthesised?
The nano-machinary of energy production ATP synthase is well known to exist on mitochondrial inner membrane and chloroplasts. But how and where are they formed or synthesised ?
Sarika
- 29
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1
vote
3 answers
Are there any drugs that target the lipid envelope of viruses?
Many drugs go after the unique viral enzymes but do any target their lipids? Viral membranes are of course similar to the host membrane but might have a different composition and do have a different curvature and protein composition. Is anybody…
SeanJ
- 538
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1
vote
0 answers
Difference between infectivity and cell fusion abillity of Virus. (COVID 19)
I'm a computational chemist who have interest in COVID-19.
As a physical chemist, I'm lack of basic knowledge for biology.
What is the difference between 'infectivity' and 'membrane fusion activity'?
I thought that, for corona virus, infection is…
user59027
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