• The various cytoskeleton elements such as microtubules and microfilaments are made of?

    The protein tubulin
    The protein tubulin
    1 answer · Biology · 4 years ago
  • Why do denatured proteins aggregate in aqueous environment?

    Best answer: A protein folds such that its hydrophobic groups are "shielded" from the outside aqueous environment. If the protein is unfolded, these groups will be exposed. So denatured proteins have a tendency to aggregate in such a way that will place hydrophobic groups together.
    Best answer: A protein folds such that its hydrophobic groups are "shielded" from the outside aqueous environment. If the protein is unfolded, these groups will be exposed. So denatured proteins have a tendency to aggregate in such a way that will place hydrophobic groups together.
    1 answer · Biology · 4 years ago
  • Which fragment will require a higher agarose % in the gel?

    Best answer: The agarose gel acts as a sieving matrix. The reason larger DNA fragments migrate slower is that they have more surface area and hence are more impeded by the gel. Therefore, the smaller the fragment, the faster it migrates. So if you tried running both fragments on a standard ~0.8% agarose gel, the 250 base pair fragment would run off... show more
    Best answer: The agarose gel acts as a sieving matrix. The reason larger DNA fragments migrate slower is that they have more surface area and hence are more impeded by the gel. Therefore, the smaller the fragment, the faster it migrates. So if you tried running both fragments on a standard ~0.8% agarose gel, the 250 base pair fragment would run off the gel. In order to resolve smaller fragments, you need a higher percentage of agarose. So the answer is Fragment A.
    1 answer · Biology · 4 years ago
  • Right definition of hyper/hypotonic?

    It sounds like you understand the basic idea behind osmosis. The only problem I have with your answer is that you say "the solution with the high concentration of the solute is hypertonic and the solution with the low concentration is hypotonic." You can't really call a solution hypertonic or hypotonic by itself. They're relative... show more
    It sounds like you understand the basic idea behind osmosis. The only problem I have with your answer is that you say "the solution with the high concentration of the solute is hypertonic and the solution with the low concentration is hypotonic." You can't really call a solution hypertonic or hypotonic by itself. They're relative terms, meaning that it's only when making a comparison that you can use them. You can say something like "compared to the inside of the cell, the salt solution is hypertonic."
    2 answers · Biology · 4 years ago
  • What single factor determines if an isosmotic solution will be isotonic or hypotonic with blood?

    Best answer: Solute concentration
    Best answer: Solute concentration
    2 answers · Biology · 4 years ago
  • Can someone please explain gel electrophoresus?

    Best answer: Gel electrophoresis is a method of separating DNA fragments or proteins. I will explain the former first. What gel electrophoresis consists of is loading samples containing DNA fragments stained with a dye into a small slab of agarose gel submerged in a liquid buffer that conducts electricity. At one end of the gel is an anode, and at... show more
    Best answer: Gel electrophoresis is a method of separating DNA fragments or proteins. I will explain the former first. What gel electrophoresis consists of is loading samples containing DNA fragments stained with a dye into a small slab of agarose gel submerged in a liquid buffer that conducts electricity. At one end of the gel is an anode, and at the other is a cathode (negative and positive electrodes). Since DNA has a negative charge, it will migrate towards the positive electrode when a electric current is applied across the gel. The gel itself acts as a sieving matrix, which in simple terms basically means it makes it harder for the DNA fragments to move. Large fragments will resist migration more so than small fragments, so the end result is that small pieces of DNA migrate farther down the gel than large fragments do. Since they're dyed, you will actually be able to see dark bands of DNA on the gel with your naked eye. You will have also run a ladder consisting of similarly stained DNA fragments of known sizes. You then compare the positions of the other bands to the positions of the bands in the ladder to figure out their sizes in base pairs. There is also a particular type of gel electrophoresis called SDS-PAGE (sodium dodecyl sulfate polyacrylamide gel electrophoresis) which is used to separate proteins by mass. It's slightly more complicated than DNA electrophoresis since every protein has a very distinct shape and also a distinct charge. This is a problem since both of those things will affect how the protein moves through the gel. This is what the SDS is for. SDS is a detergent that denatures proteins. It also binds to them stoichiometrically, or in a way that makes them all have the same charge. Proteins migrate based on their charge to mass ratio. By making all of your proteins have the same charge, you ensure that any differences in migration are entirely due to differences in mass. Again you will have also run a ladder to produce bands of known masses to which you can compare the others.
    1 answer · Biology · 4 years ago
  • Assuming that rats and humans have the same LD50, how much salt would a 155 lb person have to consume to have?

    Best answer: The LD50 is the amount of a given substance it would take to kill half the members of a tested population. In other words, the amount of the substance you would need to consume to have a 50% chance of dying. We know that the LD50 of NaCl is 4 g/kg in rats. Assuming that it's the same for humans, the question is asking what amount of... show more
    Best answer: The LD50 is the amount of a given substance it would take to kill half the members of a tested population. In other words, the amount of the substance you would need to consume to have a 50% chance of dying. We know that the LD50 of NaCl is 4 g/kg in rats. Assuming that it's the same for humans, the question is asking what amount of NaCl, in grams, it would take for a human to have a 50% chance of dying. You can easily solve if you convert 155 pounds to kg. One pound is approximately 0.45 kg. 155 pounds * (0.45 kg / pound) = 69.75 kg = ~70 kg m = (4 g / kg) * 70 kg = 280 g The question calls for one significant figure so you can round up to 300 g.
    1 answer · Biology · 4 years ago
  • What is the pH of a 1 milimolar NaOH solution?

    Best answer: You can assume that the concentration of OH- in a 1 mM NaOH solution is also 1 mM. Just as pH = -log[H ] pOH = -log[OH-] For the above equations to work, the concentrations must be in molar. 1 mM * (1 M / 1000 mM) = 0.001 M Then we can use the equation above to solve for the pOH: pOH = -log(0.001) = 3 We want the pH. The following... show more
    Best answer: You can assume that the concentration of OH- in a 1 mM NaOH solution is also 1 mM. Just as pH = -log[H ] pOH = -log[OH-] For the above equations to work, the concentrations must be in molar. 1 mM * (1 M / 1000 mM) = 0.001 M Then we can use the equation above to solve for the pOH: pOH = -log(0.001) = 3 We want the pH. The following is always true: pOH pH = 14 Since we know the pOH, we can very easily figure out the pH. 3 pH = 14 pH = 11
    1 answer · Biology · 4 years ago
  • Why is it that when the concentration of the product is high the rate of reaction is low?

    Best answer: The rate of an enzymatic reaction is generally proportional to substrate concentration, but only up to a certain point. If the substrate concentration gets high enough, the reaction becomes saturated in that all of the active sites are already occupied by substrate (assuming there's a fixed number of enzymes). In that case, the speed... show more
    Best answer: The rate of an enzymatic reaction is generally proportional to substrate concentration, but only up to a certain point. If the substrate concentration gets high enough, the reaction becomes saturated in that all of the active sites are already occupied by substrate (assuming there's a fixed number of enzymes). In that case, the speed at which the enzyme does whatever it's supposed to do is the rate-limiting factor. I think your teacher was trying to convey the idea of feedback inhibition. If you already have bucket loads of product, and that product inhibits the enzyme, you will have very little if any reactions occurring. Similarly, if you don't have that much product, chances are most of the enzymes are not being inhibited and the reaction will go. In my opinion, the problem with those two statements is that they incorrectly use the concept of reaction rate. The rate of the reaction has nothing to do with the concentration of the product and everything to do with the concentration of the substrate and enzyme and the properties of the enzyme.
    1 answer · Biology · 4 years ago
  • If you dilute 55 mL of a 4.6 M H2SO4 solution to a final volume of 250 mL, what is the new concentration of H2?

    Best answer: Use the equation C1V1 = C2V2 where C is concentration, V is volume, and the 1 and 2 denote starting and final values, respectively. In this case: C1 = 4.6 M V1 = 55 mL C2 = ? V2 = 250 mL (4.6)(55) = 250x 253 = 250x x = 1.012 M
    Best answer: Use the equation C1V1 = C2V2 where C is concentration, V is volume, and the 1 and 2 denote starting and final values, respectively. In this case: C1 = 4.6 M V1 = 55 mL C2 = ? V2 = 250 mL (4.6)(55) = 250x 253 = 250x x = 1.012 M
    1 answer · Biology · 4 years ago
  • If I take a solution that has a pH of 11 and dilute it 100x, what will be the new pH?

    Best answer: The pH scale goes in powers of 10, so a solution with a pH of 4 is 10 times more acidic than one with a pH of 5; a solution with pH 4 is 100 times more acidic than one with a pH of 6, and so on. For a solution with pH 11, a 100X dilution will make it 100X less basic (or more acidic depending on how you look at it). So following the... show more
    Best answer: The pH scale goes in powers of 10, so a solution with a pH of 4 is 10 times more acidic than one with a pH of 5; a solution with pH 4 is 100 times more acidic than one with a pH of 6, and so on. For a solution with pH 11, a 100X dilution will make it 100X less basic (or more acidic depending on how you look at it). So following the statement above the new pH will be 9.
    1 answer · Biology · 4 years ago
  • Does anyone know what insect this is?

    It looks like a boxelder bug to me. They're harmless but can be very annoying.
    It looks like a boxelder bug to me. They're harmless but can be very annoying.
    3 answers · Biology · 4 years ago
  • When the turgor pressure of a plant increases, does that indicate that the cell is hypotonic, hypertonic, or i?

    Best answer: If turgor pressure increases, the cell was hypertonic relative to the outside environment.
    Best answer: If turgor pressure increases, the cell was hypertonic relative to the outside environment.
    1 answer · Biology · 4 years ago
  • How do you approximate the pH based on transmittance and absorbance data?

    Best answer: "How is absorbance and transmittance related to pH?" To figure this out, you need to make a two standard curves (graphs) using something like Microsoft Excel. Using the absorbance values for the solutions of known pH, plot absorbance versus pH. Then do the same for transmittance versus pH. In Excel, you can then use the... show more
    Best answer: "How is absorbance and transmittance related to pH?" To figure this out, you need to make a two standard curves (graphs) using something like Microsoft Excel. Using the absorbance values for the solutions of known pH, plot absorbance versus pH. Then do the same for transmittance versus pH. In Excel, you can then use the linear regression function to get an equation in the form of y = mx + b. Then, using the spectrometer values you collected for the unknown solutions, you can solve for the pH. For instance, you plot pH on the x-axis and transmittance on the y-axis. Unknown solution #1 has an transmittance of 10. You can then plug it in to the equation for y and solve for x (bear in mind you will have the slope, m, and also the constant b once you do the linear regression). For the purpose of simplicity, we'll say m = 1 and b = 5 y = 1x + 5 10 = 1x + 5 5 = 1x x = 5 = pH
    1 answer · Biology · 4 years ago
  • What is the purpose of ATP in the cell?

    ATP is not energy. ATP is a molecule that acts as a source of energy due to its high-energy phosphate bonds. In biological systems, many reactions require energy input in order to proceed. You can't simply raise the temperature since that would harm the organism, so instead reactions are coupled with ATP hydrolysis. One of the phosphate bonds... show more
    ATP is not energy. ATP is a molecule that acts as a source of energy due to its high-energy phosphate bonds. In biological systems, many reactions require energy input in order to proceed. You can't simply raise the temperature since that would harm the organism, so instead reactions are coupled with ATP hydrolysis. One of the phosphate bonds is broken, and the bonds that form after this occurs are lower in energy. That "leftover" energy helps the reaction to go.
    4 answers · Biology · 4 years ago
  • What is the concentration of H+ and OH- in pH 2 water?

    Best answer: Knowing the pH, you can solve for the H+ concentration using the formula: pH = -log[H+] 2 = -log[H+] -2 = log[H+] 10^-2 = [H+] [H+] = 0.01 M The following is always true: pH + pOH = 14 We know the pH so we can easily find the pOH 2 + pOH = 14 pOH = 12 Then pOH = -log[OH] 12 = -log[OH] -12 = log[OH] 10^-12 = [OH] [OH] = 1 * 10^-12 M show more
    Best answer: Knowing the pH, you can solve for the H+ concentration using the formula: pH = -log[H+] 2 = -log[H+] -2 = log[H+] 10^-2 = [H+] [H+] = 0.01 M The following is always true: pH + pOH = 14 We know the pH so we can easily find the pOH 2 + pOH = 14 pOH = 12 Then pOH = -log[OH] 12 = -log[OH] -12 = log[OH] 10^-12 = [OH] [OH] = 1 * 10^-12 M
    1 answer · Biology · 4 years ago
  • A cell will uptake large molecules from the extracellular fluid by the process of __________.?

    The answer is endocytosis. Exocytosis occurs when a cell releases something into the ECF.
    The answer is endocytosis. Exocytosis occurs when a cell releases something into the ECF.
    9 answers · Biology · 4 years ago
  • Ribosomes are organelles that function in?

    I would say C. Although it is poorly worded, ribosomes don't do any of the other options. Ribosomes synthesize proteins during translation. I guess a protein is technically a "gene product," but I've never seen that term before.
    I would say C. Although it is poorly worded, ribosomes don't do any of the other options. Ribosomes synthesize proteins during translation. I guess a protein is technically a "gene product," but I've never seen that term before.
    3 answers · Biology · 4 years ago
  • I AM SO CONFUSED SOMEONE HELP?

    Best answer: You'll never learn this stuff if you don't try it yourself, but I'll show you how to do the first one. You have to use the equation C1V1 = C2V2 where C is concentration, V is volume, and the 1 and 2 denote starting and final values, respectively. For the first problem: C1 = 0.1 M V1 = ? C2 = 20 mM V2 = 100 mL First of... show more
    Best answer: You'll never learn this stuff if you don't try it yourself, but I'll show you how to do the first one. You have to use the equation C1V1 = C2V2 where C is concentration, V is volume, and the 1 and 2 denote starting and final values, respectively. For the first problem: C1 = 0.1 M V1 = ? C2 = 20 mM V2 = 100 mL First of all, the units of concentration don't match. You need to convert either C1 to millimolar or C2 to molar. I'll convert C2 to molar 20 mM * (1 M / 1000 mM) = 0.02 M Now we can set up the equation: 0.1x = (0.02)(100) 0.1x = 2 x = 20 mL Take 20 mL of the 0.1 M sucrose solution and bring the volume up to 100 mL with 80 mL of dH2O.
    1 answer · Biology · 4 years ago