PhysioEx Lab Report: Exercise 1, Activity 3 - Simulating Osmotic Pressure

6/19/2020 PhysioEx Exercise 1 Activity 3 PhysioEx Lab Report Exercise 1: Cell Transport Mechanisms and Permeability Activity 3: Simulating Osmotic Pressure Name: Date: 19 June 2020 Pre-lab Quiz Results You scored 50% by answering 2 out of 4 questions correctly. 1 Which of the following is true of osmosis? You correctly answered: It is a type of diffusion. 2 Which of the following occurs when a hypertonic solution is added to cells? You correctly answered: The cells shrink. 3 The variable that affects osmotic pressure is Your answer: the concentration of diffusing solutes. Correct answer: the concentration of nondiffusing solutes. 4 The net movement of water would be into the cell in a Your answer: isotonic solution. Correct answer: hypotonic solution. Experiment Results Predict Questions 1 Predict Question 1: What effect do you think increasing the Na + Cl - concentration will have? Your answer: decreased osmotic pressure. 2 Predict Question 2: What do you think will be the pressure result of the current experimental conditions? Your answer: pressure above the left beaker. Stop & Think Questions 1 Why do you think there is no pressure change? 1/4 6/19/2020 PhysioEx Exercise 1 Activity 3 You correctly answered: Sodium is able to diffuse through the pores. 2 Why do you think there was no pressure change? You correctly answered: There is no net movement of water because the solute concentrations are the same. Experiment Data Run Number Solute MWCO Start Conc. L (mM) Pressure L (mm Hg) Start Conc. R (mM) Pressure R (mm Hg) Rate (mM/sec) 1 Na+ Cl- 20 5.00 170 0.00 0 0.0000 1 Albumin 20 0.00 170 0.00 0 0.0000 1 Glucose 20 0.00 170 0.00 0 0.0000 2 Na+ Cl- 20 10.00 340 0.00 0 0.0000 2 Albumin 20 0.00 340 0.00 0 0.0000 2 Glucose 20 0.00 340 0.00 0 0.0000 3 Na+ Cl- 50 10.00 0 0.00 0 0.0167 3 Albumin 50 0.00 0 0.00 0 0.0000 3 Glucose 50 0.00 0 0.00 0 0.0000 4 Na+ 100 0.00 136 0.00 0 0.0000 100 0.00 136 0.00 0 0.0000 Cl- 4 Albumin 4 Glucose 100 8.00 136 0.00 0 0.0000 5 Na+ Cl- 100 0.00 0 0.00 0 0.0000 5 Albumin 100 0.00 0 0.00 0 0.0000 5 Glucose 100 8.00 0 8.00 0 0.0000 6 + Na Cl 200 0.00 0 0.00 0 0.0000 6 Albumin 200 0.00 0 0.00 0 0.0000 6 Glucose 200 8.00 0 0.00 0 0.0036 7 + Na Cl 200 0.00 153 0.00 0 0.0000 7 Albumin 200 9.00 153 0.00 0 0.0000 7 Glucose 200 0.00 153 10.00 0 0.0044 - - Post-lab Quiz Results You scored 50% by answering 2 out of 4 questions correctly. 1 If you double the concentration of a nondiffusible solute that is on one side of a membrane, the osmotic pressure will 2/4 6/19/2020 PhysioEx Exercise 1 Activity 3 You correctly answered: double. 2 Which membrane did not allow Na + Cl - to pass through? Your answer: 100 MWCO. Correct answer: 20 MWCO. 3 When a solute is able to diffuse through a membrane You correctly answered: equilibrium is reached. 4 Water diffuses Your answer: against its concentration gradient. Correct answer: toward solutes. 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 results did not compare with my prediction because as the Na+Cl- was increased from 5mM to 10mM the osmotic pressure increased from 170 to 340. 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 it is always trying to balance itself out by finding ways to try and make things equal on both sides of the membranes, but it is not always possible One way that osmosis is different from simple diffusion is the medium that are used; osmosis uses water or liquids only, while diffusion can use different mediums such as gas or liquids. 3 Solutes are sometimes measured in milliosmoles. Explain the statement, “Water chases milliosmoles.” Your answer: Water wants to go toward the area with the highest concentration and 1000 osmoles are higher than 1 osmole. 3/4 6/19/2020 PhysioEx Exercise 1 Activity 3 4 The conditions were 9 mM albumin in the left beaker and 10 mM glucose in the right beaker with the 200 MWCO membrane in place. Explain the results. How well did the results compare with your prediction? Your answer: The pressure in the left beaker increased because it was allotting for the pressure required for the equilibrium of the glucose, while the 9mM of albumin stayed the same. 4/4