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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 look at some of the work by Randy Schekman and Tom Rapoport, who have done a lot of pioneering work in this field and have papers from more than two decades ago ...


3

Yes there is a difference in the number of phospholipid molecules because of the curvature. This is very evident when there is a lot of bending as in case of exocytosis (see here) but otherwise I do not think there would be an enormous difference in the number of phospholipids between inner and outer surface of the bilayer. Assumptions: Cell is spherical ...


3

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 charges move into a cell, there is less positive charge outside the cell where the electrode is, so it becomes more negative. This is called a "sink" ...


3

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 — permeating the lipid bilayer. Presumably you have already come to the conclusion that molecular dynamic simulations are probably a good shot for exploring what may ...


2

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 surface of chromosomes and fuse with each other to form a double membrane around the chromosomes (how this happens is not clear, except that integral membrane ...


2

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 tea is water with dissolved chemicals from the leaves. Note, the word chemicals is not to be interpreted in a negative way because everything (including water) ...


2

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. Out in the environment where the virus is found in surfaces and such, sure, one can target the lipid envelope using soaps/detergents and such, but you wouldn't ...


2

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 diffusion of a polymer (starch) but will allow the passage of a small molecule (glucose). The molecular weight cut-off of the tubing was probably 10 kilodaltons or ...


1

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 causes an increase in area for better action of mucus which protects the body from entry of dirt, pathogens and loosing the moisture. Anaomically: as @Bryan ...


1

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. Imagine the parietal pleura running along the inside of the ribcage...when it gets to the middle of the chest (the mediastinum), it folds over, or "turns the ...


1

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 example, for a typical neuronal potential). Therefore, the sum of positive and negative charges in any compartment is always almost zero (to several decimal places ...


1

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 yourself pointed out that integrins attach to actin filaments. b. A protein that is enzymatically active and membrane-bound will function significantly ...


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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 of the membrane towards water and the solutes. A semi-permeable membrane has different permeability for different molecules. There are cases when one of these ...


1

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 some damage in the process. At our lab we regularly use glass bead transformation for microalgae transformation. The microabrasion allows DNA to go in so I ...


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