Describe a patch-clamp experiment. How does it work, what are you measuring, what is the significance of these types of experiments?
207400
Patch clamp experiments measure flux through an ion channel. A tiny piece of cell membrane containing the channels of interest is held in a solution at the tip of a pipet connected to a probe that meaures the concentration of ions in the pipet compared to the solution. You can look at how drugs and volatge and things like that affect the opening of ion channels.
249945
First: Pay attention in class, this is stuff they teach in 7th grade. \n\nSecond: the answer is likely A because that's what the experimenter is 'controlling' but it's a very poorly worded question. The common verbage used is 'dependant' or 'independant' variables. \n\nI'm assuming that your teacher is either ignorant or very mean. Either way, my condolences.
600862
They are also used in pump-probe experiments-- if you want to measure things (atomic motion, for instance) on a very short time scale, you would need a very short pulse.  \n\nA pump-probe experiment uses one laser pulse to excite the sample, and then a second pulse is sent through the sample and some property of the pulse is measured i.e. transmission, reflectance, phase shift. as a function of the time interval between pulses.  From measurements at different times, you can determine the response of the sample to the laser pulse.
158146
clamp and twist is much more effective.  :)
509379
I have an answer to your question, but its easier shown than explained.\n\nI will now attempt the explanation;\n\nI am right handed BTW.\n\n(1) put tube in left hand\n\n(2) hold tube up to light so you can see manual vortex as you perform it (this is critical, because you need to see the tiny air bubbles swirl around in the mix)\n\n(3) flick BOTTOM of tube with forefinger 30-40 times GENTLY.\n\nThis is such an important technique, but often overlooked in experiments.  It is an important variable in experimental outcome.  \n\nBelieve it or not, poor mixing techniques often account for poor results.  \n\nNot only that, but the VORTEX-ER  is NOT always the best way to mix stuff up.  It can be too harsh, depending on what you have in the tube.\n\nFor example, I work with DNA (which is a very long molecule).\n\nI want it to be in its most native and natural state (which is a very long molecule, as I just mentioned).  If I VORTEX a tube containing DNA, I run the risk of MECHANICALLY breaking up the molecule.\n\nThe method I am describing is the best because it is gentle (no matter what size molecules you are working with) and fool proof.\n\nLet me just add this side note:  The smaller the molecules you are working with the less times you have to flick your tube.  I would not go below 15 times though.  \n\nThis is an important question to Scientists!   And I had fun thinking about the answer.  Please spread the good Karma!
324156
This question is basically nonsense....\n\nBut, an experiment is a test or series of tests designed to isolate, quantify, and clarify whether a preconceived idea or theory is correct.\n\nHow to define that using mathematics...haven't a clue.
525587
How about visiting this site:\n\nhttp://www.all-science-fair-projects.com/category0.html
589256
iron clamp is typically used to set up it clamps to a pole to hold things like the iron ring. The iron ring is clamped to the pole to hold things like a wire mat that can be placed over a Bunsen burner that is the flame thing :)  A rubber stopper is used to close a flask either Erlenmeyer or round bottomed wash bottles typically hold distilled water to use in experiments alcohol lamps work like little mini Bunsen burners A thistle tube is a piece of laboratory glassware consisting mostly of a shaft of tube, with a reservoir and funnel-like section at the top. Thistle tubes are typically used by chemists to add liquid to an existing system of apparatus.\n\nThe thistle tube shaft is designed to allow insertion through a small hole present in some stoppers, permitting the tube to be inserted into a flask, such as an erlenmeyer flask.\n\n Sorry I don't know what the others are  Titration is a process not an apparatus it is used to test acids and bases .  Hope this helps.
154350
I've been reading up on this new research as well. I'm really excited about it and am curious to see how well it works in human trials. Unfortunately, it wouldn't be the first time something looks promising in lab animals but fails miserably in human trials.
229489
Depends a bit on what grade you're in.  I'm gonna guess that since this assignment is about measurement in experiments, you're at a pretty basic level in science.\n\nA pendulum is a great thing for doing experiments involving measuring.  All you need is two or three small weights of different masses, a piece of string to tie them to, and a fixed point from which to hang it and let it swing.  With this you can do experiments measuring distance, time and mass.  Does the pendulum's period (the time it takes to swing back and forth once) change as the length of the swing shortens?  Does it change if you change the mass of the weight?  How about the length of the string?  Or, measure how long it takes to go from one swing length (say, 6 inches) to almost standing still (about 1/4 inch for the cutoff).  Does this change with the length of the string, or the mass of the weight?\n\nYou could have a whole table of measurements of the different factors (length of swing, length of string, mass of weight) and determine wich factors are constant and which are variable.\n\n\nA similar experiment is the one where Galileo tested to see if a heavier object actually falls faster than a lighter one.  The old story is that he dropped balls of different weights off the Tower of Pisa.  But what he actually did, is he took balls that were the same size but different weights and rolled them down a ramp, and timed them to see how fast they rolled down.  Can you figure out why he did it this way, and didn't just drop weights from a height?\n\nGood luck!
121407
Since we don't know what "this lab" or "this investigation" refers to, we probably can't really help you.  Try asking a classmate or the teacher for help, since they know what "this" refers to.
78977
I pierced a candle with the needle and carefully placed the needle on water surface. It floated well. \n\nThis due to the surface tension effect.\n\nNext I did with another needle without wax coating. This time it floated once in many trials.\n\n\nNext I placed the needle on a piece of blotting paper and placed it on the surface of water. The blotting paper in few seconds went inside leaving the needle floating.
562884
Think about how your knee jumps when a doctor hits it with the mallet.  Its a closed loop.  It never goes back up the spinal cord.   In other words - it activates the stretch receptors.
428791
During class discussion, introduction of the term "force constant", (the slope of the general equation F = -kx) should be introduced. This law is called Hooke's Law. Put simply, Hooke's law expresses the "stretchiness" of a given spring. \n\n \nDuring whiteboard discussions of the students' results they should discover that force (F) is proportional to the displacement (x) of the spring. This displacement is the distance that the spring stretches from its normal (equilibrium position or length) when a mass is suspended from it. (Keep in mind this is for a static test of the spring.) The slope of the graph is called the force constant (k) for that particular spring (in N/m units). A stiffer spring has a higher spring constant. No matter how much mass is hanging from the spring, the spring will exert a constant force resisting the force of gravity on the hanging mass. \n\nStudents may find that the slope of the F vs. x relation is not a straight line, that is, that the spring constant, k, is not "constant" for some springs. Note that most springs are not "ideal", and therefore many do not obey Hooke's law, especially over large ranges in forces. If students find that the function that best fits their F vs. x data is not a straight line. Non-linear, empirical best-fits (regression curves) to the data collected are fine to introduce at this point, as well as the limitations of many springs in that they do not all conform to Hooke's law. \n\nSome groups should show a large y-intercept for their spring F vs x graphs. Discuss the significance of the y-intercept and have the students propose explanations for this. They should recognize that the stiffer springs require more force to get it to start stretching. Hence there is a threshold value of force required to register a measureable displacement, and this threshold is the y-intercept of the F vs x graph (for x = 0). \n\nDuring the class discussion, you should point out the relationship between the equation for the potential and kinetic energy of the jumper (and his/her potential energy (P.E. = mgh) at that position) to the equation for the spring (F = -kx). It will be necessary to make this clear before proceeding to the Egg Test.  For the prediction that the students will make, the "h" value is the height of the weight suspended from the spring above the top surface of the egg. The students will need to accurately predict this distance, and set up their experiment so that the maximum extension of the spring when the weight is released is exactly "h". This will permit the weight to touch, but not crack the egg. The "x" value is the distance the spring will stretch using the prescribed mass. The gravitational potential energy is a function of the height of the object and the object's mass. The kinetic energy is a function of the object's velocity and mass. Since the mass remains constant in the fall of a bungee jumper, its value cancels in the equation leaving gh = 1/2v2, and gh + 1/2kx2 = 0. Finally, when solving for the height of the "platform" of the jumper/object, students need to find that h = 1/2kx2 /g.\n\nF = ma and mgh = 1/2mv2 and F = -kx\n\nSince PE = KE, so PE + 1/2mv2 = 0, so mgh = 1/2 kx2 and mgh + 1/2 kx2 = 0
564435
It sounds like you are creating a basic electrical circuit. with the batteries, wires, bulbs and paper clip you can make either a series or parallel circuit. The light bulbs will light up when you have a complete single loop for series. When you measure the current it should be the same anywhere on the circuit. In a parallel circuit you are splitting the circuits into three or more branches, with one bulb on each side. When measured each branch should be using half the current. You shouldn't have any problem finding a site online that shows this experiment. use keywords, including science experiments for kids. I found the experiment in Reader's Digest,"How Science Works"
436204
tiny amounts of chemical can stick to differnt things, like stir bar, stir rod, thermometer and if you remove these items before the experiment is over then you remove some chemicals.  Other kinetics events that your not considering. as in pressure, humididtym and so on.  If you used a Ph probe then maybe it wasn't calibrated right or isn't properly maintained
20907
I'll be glad to help. Could you provide more detail? Do you remember any examples of the (something ridiculous) that I could work with? Thanks. If you can get me more details I'll edit my answer if I find something.