What organic molecule can be detected with Lugol’s? By using the Lugol’s iodine test, we can detect the presence of starches. Why put Lugol’s in the beaker and not the bag? When we put the Lugol’s regent (I2Kl) in the beaker, we can observe the effects of osmosis as the Lugol’s regent (I2Kl) solution on the outside of the beaker permeates the intestine (Dialysis tubing) inducing a chemical reaction that will turn the liquid in the intestine (Dialysis tubing) blue-black. If the amylase successfully digests the starch, what results would you expect? If the amylase successfully digests the starch, I would expect a no color change occur as well as a presence of glucose in the intestine (Dialysis tubing). If the amylase only partly …show more content…
Were Lugol molecules able to cross the membrane? Yes, the starch molecules were able to cross the membrane as we observe the color changes that occur inside the intestine (Dialysis tubing). What is your conclusion regard amylase digestive activity? In this experiment, I concluded that amylase have the abilities to catalyze the breakdown of the starch into glucose. Also, some molecules, such as the Lugol’s regent (I2Kl) and glucose are able to permeate through intestine (Dialysis tubing) while others, such as starch is not able to permeate through the (Dialysis tubing). What does this experiment tell you about the size of glucose molecules and membrane permeability? This experiment tells me the size of the glucose molecule is very small in comparison to starch molecule. They have high membrane permeability that allows them to permeate through the intestine (Dialysis tubing); this is supported by the presence of glucose in the water when we conducted the glucose test. In the experiment, did the movement of glucose and starch molecule reflect the expected results of biological simulation? In this experiment, the glucose and starch molecules accurately reflected the expected results of the biological simulation. Animal’s starch molecule can’t cross the plasma membrane to leave the intestine, similarity in our experiment, the starch solution were not able to permeate through the intestine (Dialysis tubing), thus a
Certain substances are able to diffuse across plasma membranes under the right conditions through selective permeability. The selection of these certain substances allows for cells to maintain homeostasis, as these substances move from higher concentration to lower concentration. The purpose of this experiment is to see whether or not Lugol’s will be able to diffuse across dialysis tubing, which acts as a membrane. Lugol’s turns black when it interacts with starch, which will make the diffusion easy to see. This is all based off of a caterpillar eating a plant. The starch present in the leaves causes the caterpillar to produce amylase, which breaks down starch. In one experiment, the tubing will contain starch and amylase, while the other tubing
6. What results would you expect if the experiment started with glucose and Lugol’s Solution
By examining the filtration results, we can predict that the molecular weight of glucose must be
When glucose carriers in the membrane were set to 500, the glucose transport rate for 2.00 mM of glucose was .0008 mM/min. Equilibrium was reached at 43 minutes. At 700 glucose carriers the rate was .0010 mM , and equilibrium was reached at 33 minutes. When the glucose carriers was set at 900 the rate was .012 mM/min, and equilibrium was reached at 27 minutes. After changing the glucose concentration to 8.0 mM, the glucose transport rate with 500 carrier proteins was .0023 mM/min, and equilibrium was reached at 58 minutes. With the simulation set at 700 carrier proteins the rate was .0031mM/min, and equilibrium was reached at 43 minutes. When the simulation was done with 900 carrier proteins the glucose transport rate was .0038, and equilibrium was reached at 35 minutes.
My prediction for the effect Na+Cl- might have on glucose transport was that the glucose transport rate would decrease. I picked this choice because I thought having Na+Cl- in one beaker would limit the space needed for proper glucose diffusion. All of the other runs involved water, so I predicted that adding a new solute could slow diffusion. The results opposed my
Purpose: The purpose of this lab is to familiarize you with osmosis and, specifically, what happens to cells when they are exposed to solutions of differing tonicities.
Human error is easily obtained when working on an experiment with so many different solutions, time measurements, and accuracies of measurements. An easy mistake could have been made while waiting 15-20 minutes for the Carb Cutter to digest. With the time crunch in the Biology Lab, the Carb Cutter may not have been completely digested before rushing to begin the experiment. The results from the experiment showed an increase in absorbance with the Carb Cutter pill, which is not accurate because there is no way that more starch was made in the solution. Given more time for the procedure, this lab experiment may have received more accurate results.
Table 1 shows the contents of the bags and the content of the concentration it was submersed in. Bags 2-4 each contain a solution of both sucrose and water. These bags were each put into beakers containing hypertonic solution. These bags gained weight over time because the water moved from its high concentration inside the beaker to the low concentration inside the membrane of the artificial cell, the membrane being the bags that consisted of dialysis tubing. The
In this experiment, we will investigate the effect of solute concentration on osmosis. A semi‐permeable membrane (dialysis tubing) and sucrose will create an osmotic environment similar to that of a cell. Using different concentrations of sucrose (which is unable to cross the membrane) will allow us to examine the net movement of water across the membrane.
Three peaks are observed in Figure 1 (concentration of glucose vs. elution volume) which was expected due to the results in table 4 that show intervals of elution. The intervals of the elution are represented as peaks on the graph. The intervals are due to the glucose molecules that enter the beads of the column causing the glucose molecules to elute slowly. Two peaks are observed in Figure 2 (concentration of starch vs. elution volume), which was not expected. One peak was expected for the
The difference is that along with large molecules, living cells prevent molecules with positive charges and solubility. This is not representing in dialysis tubing, and is only found in living cells because the tubing is only based on molecular size (98). When referring the rate of diffusion, the concentration gradient influences the diffusion rate, based on the factors of temperature. The ability for molecules diffuse from high to low concentrations primarily depends on the concentration gradient between the two areas.(96-99). My hypothesis for the study is that in the hypotonic, hypertonic, and isotonic solutions, the direction and rate of osmosis will determine based on the concentration inside the dialysis tubing. My prediction is that if the solution is hypotonic the results will decrease, if the solution is hypertonic the results will increase and if the solution is isotonic the solution will vary and or remain constant.
The dialysis tubing used was meant to act as a semi-permeable membrane, which allows molecules that are smaller in size to pass through it. Molecules that it allows are water, Lugo’s, and glucose. However, starch is too big to pass through this membrane. Amylase can digest starch and turn it into glucose, thus
The major objective of the experiment was to test the effect of the concentration gradient on the diffusion rate. It was hypothesized that the greater the stronger the concentration gradient, the faster the rate of diffusion would be. To test this, dialysis tubes were submerged in different concentration fructose solutions. We weighed the tubes at specific time intervals to measure the rate of diffusion of water in each different solution. The results illustrated that increased concentration gradient increases the rate of diffusion of water in the tubes. We concluded that as concentration of the
enzymes that will be used during this lab to test the ability of amylase to break down starch ,a
The beaker was then filled partially with distilled water; 1 ml of potassium iodide was then added, and the solution was tested for the presence of glucose. This data was recorded in table 1 on the data sheet along with the starting color of both the potassium iodide solution and the glucose/starch solution. The dialysis tubing was then submersed into the beaker containing the potassium iodide solution, and set aside for 30 minutes to allow maximum diffusion.