What is a buffer solution? Why do we use buffer solution for serial dilution of  yeast cells?
108204
a buffer solution is an aqueous solution of acids and salts of the acid that resist a change in pH.  If you didn't dilute the yeast in buffer, you would run the risk of killing the culture from build up of waste products.
445105
damn! i should know this...i'm a science chem/bio student\n\ngimme some time...they are basic and acidic in nature. so in solution, there's the [H] ions for reaction in/around cells
85467
Look up a product called YeastBuster by Cycles of Life.  It has many applications and has had some tremendous benefits for "clearing up" problems that nothing else can.
245193
Use your buffering equation and plug in the numbers you know to get your answer.  You might have to do reverse calulations to find your answer.
802415
Normally the particles (let us call them solutes for now) move from where they are more in concentration to where there are less solute particles in solution. This is just diffusion. This is some kind of standard stuff ALL THINGS MOVE FROM HEIGHTS to DEPTHS!! no more energy is required for this.\n\nBUT there are many more things in life which need to go against this principle and this is where the cell needs to spend energy ATP may be.. So when some particles are actively transported what it means is that energy is spent to do something against the concentration gradient. If it wants to bring more K+ ions into a cell which already has heaps when compared to the outside it needs to spend energy, There are many reasons why it may want to do it.. ... may be it wants to accumulate stuff for later (store glucose)..\n\n ..\nhope that helps,,,
632890
1 is c.  Buffer is a mixture of a weak acid and its conjugate base.\n2 is a.  pH is the dependent variable in the experiment, volume of titrant (either acid or base) is the independent variable.
768732
pH at pKa +- 1 unit. from henderson hasselbalch\npH = pKa + log [base]/[acid] \ngiving +- 1 when the ratios are 1/10 or 10/1 in concentration\nthe capacity of a buffer is achieved when the ratio of weak acid to conjugate base exceeds 10:1 or vice versa. \nDoes that help?
898113
The solute CaBr2 contains 3 ions, which are all separated when it dissolves in water.\nGlucose, although it is a big molecule, is only one particle. Therefore CaBr2 provides three times the lowering of freezing point that glucose does\nBoth substances are freely soluble because the particles have a good attraction to water. But the solution of CaBr2 will not freeze at -5C because it has 6.00M of ions in it (3 x 2.0M).
195810
Well to lyse the cell use the freeze thaw method and use a high salt solution to lyse the cell and salt out the cytosolic proteins!
1017595
A standard solution is one that has been very carefully analyzed and characterized, usually by means traceable to a central standards bureau, such as NIST, so that the value is well known and can be trusted for instrument calibrations and methods development.\n\nA control sample uses known quantities of an analyte (it may be a standard, but does not have to be) so that analytical chemists can confirm that their processes are accurate and precise.\n\nFor example, I might have a standard buffer solution that I use to calibrate a pH meter on a regular basis, say daily.  Then, during each day, as I run dozens or hundreds of pH readings, I will periodically (say, once ever 20 tests), run a control sample through to make sure my readings are still in line with what I'd expect.  This gives the customer more confidence that the readings really match the real world situation.\n\nHope that helps.
355353
The yeast is grown to a point at which it is confluent, or to a point in which the experiment may begin or end- It is then put at 4 degrees to halt the growth process and render it quiescent without killing or freezing it.  The same technique is used for mammalian cells.
355477
Buffers resist change in pH. This is generally a result of the buffer containing a mix of a weak acid and the salt of the conjugate base. \n\nWhen you add NaOH to the buffer, it dissociates into Na+ and OH-. The OH- reacts with the H+ ions which the weak acid has dissociated into (along with the conjugate base) up to the acid dissociation constant, Ka, of the acid.\n\nThis shifts the equilibrium of the dissociation reaction of the acid, and more dissociates, maintaining a relatively stable pH, as compared to when the NaOH is added to the distilled water. (If you had instead added a base, it would instead have shifted the equilibrium of the base, and, instead, more of the base would have reacted with the free H+, again, keeping the pH relatively constant)
841228
In both cases you have a semi-permeable membrane separating two solutions.\n\nIn the case of osmosis, solutes (which contribute to the phenomenon) cannot pass through the membrane and therefore the solvent has to pass through the membrane in order to equilibrate the osmotic pressure (or better yet the solvent potential) of the two solutions.\n\nIn the case of dialysis you have some solutes which can pass through the mebrane and diffuse from the solution where their concentration is higher to the one where their concentration is lower. Thus dialysis is used when you want to get rid of certain solutes or exchange them with others, while retaining some of the initial solutes in your system. E.g. if you have a protein sample that has too much salt, you can get rid of the salt (or any other small molecule that you don't want in your sample), without losing your protein, by dialysis; you can change the buffering system with dialysis. Of course there are also the medical aspects of dialysis but these have already been described in detail in the other answer.\n\nIn two words, in the case of osmosis you have net movement of solvent whereas in dialysis you have net movement of some solutes from one solution to the other.
87804
Biological solution is a solution which used for maintaining the balance of living cells.By adding this solution, some cell cultures or organ of any kinds of living thing can survive or still alive.
425518
Buffers are chemicals that help to regulate the pH level in your body. ie. acidic or basic. Your body can only function within certain range of pH, close to 7 (which is neutral). If the blood gets to basic, and acidic buffer will be sent out to level it off. If your blood becomes acidic, a basic chemical will be used to help regulate it.
1088951
Carbonic Acid is an example of a buffer. It keeps the equilibrium in your blood stream, so that the pH remains around 7.2-7.4. If there are too much acid, it acts as a base to reduce the amounts of acid, and vice versa. \n\nSuppose you injected yourself with sodium hydroxide (why, I don't know), then:\nNaOH + H2CO3 = NaHCO3 + H2O \nBut if you drank HCl instead of H2O:\nHCl + NaHCO3 = NaCl + H2CO3 \n\nObviously, the pH in your mouth is different from that of your stomach, seeing as how stomach acid is HCl. but naturally, without additional acids and bases, they are all roughly the same.
845596
The pH buffers used in a lab experiment can go "bad" at different rates depending on the way they're stored. If your buffer is always stored in a closed container, then the contamination is usually pretty low and the buffer can last for a long time. However if your buffer is constantly exposed to open air and moisture, the pH of your solution can vary quite a bit. I'm not sure if you are familiar with the effect of boiling "tap" water, but boiling the water gets rid of carbonic acid in the solution, similar to the acidity found in a soft drink. So over time, if a buffer is exposed to air, the buffer will tend to become more acidic if no other factors (contamination by other careless people in the lab for example :P) are present. Hope this helps!