6
votes
Accepted
How do membrane proteins find their target locations?
This is a great question. A comprehensive answer would be beyond the scope of an answer on a forum like this. I will summarize the best I can here, but if you are really interested in this you should ...
- 176
6
votes
Accepted
Where in the cochlea are frequencies below 200 Hz detected?
The answer is two fold, each related to the two ways pitch is encoded in the inner ear. These two mechanisms are place coding and rate coding.
Regarding place-pitch; given that there are hair cells ...
- 52.2k
3
votes
Where in the cochlea are frequencies below 200 Hz detected?
A figure like this is likely representing the best frequency for hair cells. In actuality, cells respond to a broad range of frequencies. Perceptual specificity comes thanks to lateral inhibition. ...
- 41.2k
3
votes
Accepted
How are Current Sources and Sinks for Postsynaptic Potentials defined?
Sinks and sources just refer to the sign of the local field potential measured with extracellular electrodes.
Excitation involves positive charges entering cells, depolarizing them. When positive ...
- 41.2k
3
votes
Do free computer programs exist that can simulate drug permeability in bacterial membranes?
I currently work alongside many biologists that are working on simulations of anti-microbial peptides in the membrane. These seem to have a similar mechanism to what you're aiming for — ...
- 11.3k
2
votes
How do nuclear membranes form during Telophase of Mitosis/Meiosis?
According to this book, during disassembly of the nuclear envelope, the nuclear membranes are broken down into vesicles. The nuclear membranes reform at the end of mitosis as the vesicles bind to the ...
- 2,844
2
votes
Accepted
Difference between water and tea
Your question is very awkward.
Let's define Tea as boiling leaves in water. At the end, you remove the leaves and drink the flavoured water.
At this point, the "tea" is still very much water - as in ...
- 246
2
votes
Are there any drugs that target the lipid envelope of viruses?
The lipids in the viral envelope come from chunks of the host cell membrane. Therefore, something targeting those lipids is unlikely to be virus-specific, and not suitable for use in a living animal.
...
- 41.2k
2
votes
Why is iron transported across membranes in the ferrous form?
This is not my subject, but from scanning the introductions to a couple of reviews on the general topic of iron metabolism, the following factors seem to be important:
Ferric iron is less soluble ...
- 23.8k
2
votes
Accepted
Rate of Diffusion Through Cellulose Membrane
I think that your instructor was wrong.
For the type of experiment that you describe the dialysis tubing (cellulose acetate with pores) is acting as a semi-permeable membrane which can block the ...
- 22.7k
1
vote
Number of membrane proteins of a particular type per cell
If you know the stoichiometry of a particular ion channel and do something like patch-clamp, where you know the surface area being clamped, then you can measure the ion-flux per unit time and from ...
- 9,363
1
vote
Accepted
Why are the walls of the bronchioles folded?
Those foldings are called as mucosal folds, formed by the contraction of smooth muscles , are also present in trachea, and in many other organs such as gallbladder etc.
Physiologically: This folding ...
- 4,786
1
vote
Parietal and Visceral epithelia
Yes, the parietal pleura is on the wall of the thorax. That picture isn't great. Each lung has its own pleural cavity, ie its own visceral+parietal. Another important thing is the folding over. ...
- 77
1
vote
Nernst equation and equilibrium potential
The Nernst equation should be:
$\frac{RT}{zF}\ln\left(\frac{\mathrm{Out}}{\mathrm{In}}\right) = 2.3 \frac{RT}{zF}\log_{10}\left(\frac{\mathrm{Out}}{\mathrm{In}}\right)$
You substituted for 2.3 RT/F (...
- 41.2k
1
vote
What is the basis of the endocochlear potential?
About biological electrical potentials generally
Biological potentials on the order of tens of millivolts depend on very very few ions moving (about 1/100,000 of the potassium concentration, for ...
- 41.2k
1
vote
Plasma Membrane Proteins and Cytoskeletal Attachment
a. Membrane proteins are responsible for both cell to cell recognition and cell anchoring and are stabilised by linking through to the microtubulele cytoskeletal fibres.
Not entirely correct as you ...
- 35.2k
1
vote
When does DIFFUSION occur and not OSMOSIS, and the otherwise?
But when does exactly osmosis occurs instead of diffusion?
These processes are not mutually exclusive. Both can happen simultaneously. Their rates depend on different parameters such as permeability ...
- 35.2k
1
vote
Accepted
Ways to cause membrane damage to microalgae and yeast?
To get to the membrane of these species you first need to get past a formidable cell wall. The methods listed below are therefore more aimed at making cells permeable but the membranes must sustain ...
- 1,415
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