Essay about Laboratory #1 - Cell Physiology

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

2. Does the rate of diffusion correspond with the molecular weight of the dye? The the density of the medium and the molecular weight of the dye will determine the rate of diffusion.

Review Sheet Results 1. Explain the effect that increasing the Na+ Cl- concentration had on osmotic pressure and why it has this effect. How well did the results compare with your prediction? Your answer: The increase of the Na+Cl- concentration increased osmotic pressure the Na+ Cl- molecules diffused through the 50 mwco membranes and didn't go through the 20 mwco membranes. the more Na+Cl- we added to the 20 mwco membrane, the more the osmotic pressure went up. When I looked at my results I noticed when Na+Cl- was added to the 50 mwco membrane, there was no increase in osmotic pressure. This is becasue the Sodium chloride couldn't diffuse through the 50 mwco membranes. The higher concentration of molecues on one side of the mwco membrane forces the water movement to move to the side of greater solute concentration. 2. Describe one way in which osmosis is similar to simple diffusion and one way in which it is different. Your answer: Osmosis is similar to simple diffusion because both of these precesses have the passive transport characteristic. This is where particles in a solution move from an area of high solute concentration to an are of low solute concentration. Also neither of these processes need energy from an outside source to function. Osmosis is different than simple diffusion because in osmosis, if we have a selectively permeable membrane, this membrane is

In this lab we found out that the dialysis bag contained more fluids inside it. This can happen because sucrose is small enough to pass through the selectively permeable membrane. Some errors that might have been encountered during the lab could have been the fact that some of the dialysis bags were not tightly tied with the dental floss, or that the wrong substance was used. Another possible source of error was if the carrot strips had been dehydrated from the beginning of the experiment or were already

Given the background, we hypothesized that for the first experiment, the lactase will break down lactose in milk and have a similar effect to sucrose. We also predicted that the Milk + Lactase reactant would have more glucose, the Milk + Water reactant would have a little bit of glucose broken down, the Sucrose + Lactase reactant would have less glucose than the Milk + Water reactant, and the Sucrose + Water reactant would have little to no glucose at all. As for the first procedure of the second experiment, we had hypothesized the more basic the solution would become, then the more glucose there would be. Our prediction for the first procedure of the second experiment was that there would be no glucose found in the solutions containing pH 4 and pH 7. For the second procedure of the second experiment, our hypothesis was that glucose would be present in the reactants at 4ºC and 25ºC while the reactant that had been in the hot water bath at 100ºC would have little to no glucose because it would have evaporated. We predicted that for this temperature experiment, the glucose would evaporate at 100ºC and would remain at 4ºC and 25ºC. For the first experiment we had found that a reactant of Milk + Lactase have high levels of glucose, while the other three reactants do not. As for the second experiment, for the first procedure, amounts of glucose were found in

In this lab experiment, half our group observed and measured osmosis using dialysis tubes that were represented as the semipermeable membrane. It is permeable to water and other small molecules but is impermeable to larger molecules such as the sucrose solution used in each of the four beakers and tubing. The other half of our group observed the tonicity of sheep blood to determine whether the blood was isotonic, hypotonic, or hypertonic. The 85 g/dL of NaCl solution was the ideal isotonic number in relation to the sheep blood cells as well as a reference to the other observations of the solutions.

3. What would happen to the amount of H+ secreted into the renal tubule if the activity of the Na+ /K+

We hypothesize that as the solute concentration increases, more water will diffuse into the dialysis tubing (shown by a greater percent increase in mass).

Does the membrane MWCO affect filtration rate? Yes smaller the MWCO smaller the pore size and this affected the filtration rate

With all solutes set at a concentration of 5.00 mg/ml and the MWCO set at 20, filtration stopped at 60 minutes, and the projected completion was 100 minutes. The residue analysis indicated all solutes present in the dialysis membrane. The filtrate concentrations for all solutes was 0.00 mg/ml. With all solutes set at a concentration of 5.00 mg/m and the MWCO set at 50, the filtration completed in 40 minutes. The residue analysis indicated all solutes present in the dialysis membrane. The filtrate concentration for NaCl was 4.81 mg/ml, and 0.00 mg/ml for all remaining

The lab for this paper was conducted for the topic of osmosis, the movement of water from high to low concentration. Five artificial cells were created, each being filled with different concentrated solutions of sucrose. These artificial cells were placed in hypertonic, hypotonic, or isotonic solutions for a period of 90 min. Over time, the rate of osmosis was measured by calculating the weight of each artificial cell on given intervals (every 10 minutes). The resulting weights were recorded and the data was graphed. We then could draw conclusions on the lab.

Osmosis is a special type of diffusion where water molecules move down a concentration gradient across a cell membrane. The solute (dissolved substance) concentration affects the rate of osmosis causing it either to speed the process up or slow it down. Based on this, how does different concentrations of sucrose affect the rate of osmosis? If sucrose concentration increases in the selectivity-permeable baggies, then the rate of osmosis will increase.

The following hypothesis was made in regard to effect of the concentration gradient on the rate of diffusion: The higher the concentration gradient, the faster the rate of diffusion.

If the solution in the left beaker contained both urea and albumin, which membrane(s) could you choose to selectively remove the urea from the solution in the left beaker? How would you carry out this experiment?

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.