Dipitro
10/17/2014
Osmosis Diffusion lab
Procedure1:
The solution hydrochloric acid which had a pH of 4 was mix with 0.1 phenolphthalein and the color stayed the same, it did not change. The base was sodium hydroxide which had a pH of
10 and when mix with phenolphthalein it turned fuschia.
Agar size(cm)
Surface Area
Volume
Ratio of surface area to volume
Cell A (2x2s0.5)
12cm2
2cm3
6cm2:1cm4
Cell B (1x4x0.5)
13cm2
2cm3
6.5cm2:1 cm 4
Cell C (2x4x0.5)
22cm2
4cm3
5.5cm2:1 cm4
If we put each of the block into a solution cell A will diffuse the fastest because it had a surface area to volume ratio of 6cm2 : 1 cm4 and the bigger the ratio the faster it diffuse . The one that will diffuse the slowest is C because it had a surface area to volume of 5.5cm2: 1 cm4
This lab shows how important ratio is because a higher surface area to volume ratio allows for more nutrients to enter and waste to leave, and a lower ratio makes it difficult for nutrients to enter and wastes to exit.
Procedure2:
1.Why is it important for an IV solution to have salts in it? The salts are there to prevent the cells from bursting due to lysis. It maintains an equal concentration of water and solute in and outside of the cells in the body.
2.What would happen if you were given pure water in an IV? If you were given pure water, then too much water would enter the cell, since water moves from low to high solute concentration in osmosis, this would result in the cells expanding and eventually bursting a process called lysis.
3.How would you determine the best concentration of solutes to give patient in need of fluids before you introduced the fluids into the patient’s body? It would beneficial to determine if they are dehydrated. If they are dehydrated they would need a hypotonic solution in order to add more to their system. If it’s hypotonic theres more water than solute. Hypothesis:
If a molecules is able to move through the membrane then the molecule is of opposite charge in the membrane because opposite attract and like charges repel.
Trial
Dialysis
Tubing
Beaker
Initial weight
Final weight
Difference
1
Protein
Sucrose
9.29g
6.93g
31.22%
2
NaCl
Glucose
10.63g
10.65g
.19%
3
Glucose
protein
10.97g
13.68g
24.70%
4
Sucrose
NaCl
11.61g
14.61g
25.83%
5
Water
Water
8.66g
9.59g
10.64%
Conclusion:
In this experiment, the dialysis tubing represented an animal cell. The tubing was semipermeable, just like the cell membrane. All solutions were one molar meaning that they have the same concentrations of molecules and therefore the the same water potential. An increase in weight meant molecules moved into the tubing and a decrease in weight meant molecules moved out. Movement can be the results of a molecules polarity, of the size of the molecule. In trial 1, protein moved out of the cell into the sucrose solution, In trial 2, glucose
moved into the NaCl solution. In trial 3, protein moved into the glucose solution. In trial 4, NaCl moved into the sucrose solution. In trial 5, water moved into the water tubing. Questions
1.
Each pair that I tested had a change in weight because of diffusion. The molecules either moved in or out of the dialysis tubing to go from an area of high or low concentration. Water however, should not have had an change in weight because the solution were isotonic.
2.
Comparing 1 molar of sucrose to 1 molar of NaCl, 1 M NaCl was more hypertonic because it contains more particles due to the dissociation of Na+ and
Cl. And this is showed in trial 4 when NaCl solution is moved into the sucrose solution. Glucose and NaCl are the same tonicity and the difference could be due to human error when measuring the initial weight of the cell in trial2. However, either way, glucose is more hypertonic than sucrose.
3.
Protein has higher molarity, and is showed