BIOL 382 Lecture Notes - Lecture 1: Aplastic Anemia, Sodium Chloride, Hemoglobin

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10 Jan 2018

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Experiment 1: hematocrit and tonicity of whole blood and hemolysis of red. Lab assignment questions: the horizontal line which indicates the control reading is the point of isotonicity, since it is the whole blood. The peak of the curve can be slightly higher than the whole blood due to the cells having swollen to their limit of not lysing this increases hematocrit. The solution which is isotonic with the whole blood is that which intersect the control line, or in this case is nearest to it. The 0. 16m nacl solution is isotonic as its value of 40. 000% actual hematocrit is almost identical to that of the whole blood, 40. 909%. Actual hematocrit(%) relative to blood solutions of differing nacl concentrations(m) Nacl concentration(m) t i r c o t a m e. 0: the hematocrit increases when exposed to an extremely hypotonic solution.

Related Questions

Cell Membranes Lab Report

Diffusion

Compare the following terms: solvent, solute, andsolution.

Go to Lab, Section I, Exercise 1 to explore the factorsinfluencing the rate of diffusion and complete the following:

Predict how molecular mass and temperature may affect theoutcome of this experiment.

Record the data from information in the Lab in the tablebelow.

Time (min)	Diameter (mm)
Time (min)	5Â°C MB	5Â°C PP	23Â°CMB	23Â°C PP
0
15
30
45

Construct a line graph of the data from the table above. Yourgraph should include labeled axes, units, and a legend indicatingwhich treatment is presented. Sign, date and prepare an image ofyour graph and include it with this lab report.

Osmosis

Go to Lab, Section II, Exercise 2 to view a demonstration ofosmosis and answer the following questions:

Describe the net movement of water in osmometer 1.

How is the movement of water molecules related to theconcentration gradient of the solution?

Go to Lab, Section II, Exercise 3 to observe the effect ofsolute concentration on the rate of osmosis. Answer the followingquestions:

Was the net movement of water in bags 1 to 4 into or out of thebags?

Explain the results from bags 4 and 5.

Selective Permeability of Membranes

Go to Lab, Section III, Exercise 4 to learn about theimportance of selectively permeable membranes, then complete thetable and answer the following questions:

	Contents of Beaker
	0 Min	30 Min
Starch
Chloride ion

Which substances diffused through the dialysis membrane?

How does dialysis tubing model the selective permeability of aplasma membrane?

Tonicity

Go to Lab, Section IV, Exercise 5 and 6 to observe plasmolysisin Elodea cells and tonicity in red blood cells. Summarizethe concept of tonicity using blood and Elodea cells asexamples. Your description should incorporate these terms: turgid,plasmolysis, hemolysis, and crenation.

Cells	Isotonic Solution	Hypertonic Solution	Hypotonic Solution
Elodea
RBC

Based on your previous work, reproduce the table below and drawan illustration of a single cell in each box. Include arrows toshow the direction of water flow relative to each cell and dots tosymbolize solutes. Sign, date and prepare an image of your drawingand include it with this lab report.

Cells	Isotonic Solution	Hypertonic Solution	Hypotonic Solution
Elodea
RBC

Summary Questions

Compare diffusion and osmosis. Give an example of each.

2. In which direction will osmosisoccur if a 15% sugar solution is separated from a 25% sugarsolution by a selectively permeable membrane?

3. Why did osmosis, but not diffusionof sucrose molecules, occur across the dialysis membrane containing20% sucrose solution?

4. You are having a party and thecelery is limp. What might you do to make the celery crisp (turgid)again? What will occur in the cells?

5. A small amount of fertilizer(mineral salts) will stimulate plant growth, but over fertilizationcan kill plants? Why?

6. Michael adds sugar to his coffee.Explain what in this drink is the solvent, solute, and solution.

7. You add a cube of sugar to yourdrink. How could you speed up the diffusion of sugar moleculeswithout stirring?

8. How is dynamic equilibriumestablished within a solution?

amberdeer449

1. In lecture, we described a simple osmotic pressure gradient when discussing osmosis. For question #1, describe the simple osmotic pressure gradient, in terms of osmotic pressure, that exists across the red blood cell plasma membrane when red blood cells are suspended in a severely hypotonic solution, such as a 0.2% NaCl solution. Use scientific terminology.

2. We mentioned in class that biological systems are always in a state of osmotic equilibrium due to a combination of solute diffusion in some cases and osmosis in others. In this experiment, when you add the red blood cells to a severely hypotonic solution, what substances are moving across the red blood cell plasma membrane to achieve osmotic equilibrium, Na+ and Cl- or water? Explain why based on your understanding of the permeability characteristics of biological membrane. Always use scientific language.

CAN QUESTIONS 1 AND 2 BE ANSWERED DIRECTLY AND ADEQUATLEY PLEASE.

HERE IS AN INTRO TO THE LAB EXPERIMENT

Intro:

We have known for a very long time that the mammalian red blood cell plasma membrane is very permeable to water. Even the introductory biology student understands that if you put mammalian red blood cells in water, they will rapidly swell and break open (hemolyze) due to the rapid osmosis of water into the cell. The experimental question we are asking in today's lab experiment is "Is the high water permability of mammalian red blood cell plasma membrane due solely to the lipid bilayer, or are there water channels present in the membrane?"

Experimental Design:

It has been shown by several investigators that water movement through water channels can be blocked by the known K+ channel blocker, tetraethylammonium chloride (TEAC). Brooks, Regan and Yool (2000) showed that TEAC reduces the water permeability of human water channels expressed in the plasma membranes of frog ocytes. After preincubation of the oocytes for 15 min with 100 microM TEAC, the water permeability of frog oocyte plasma membrane containing human water channels was reduced 20 to 40%. The investigators concluded that treatment of cells with TEAC can be useful in determining the presence of aquaporins in membranes.The specific objective of today's experiment is to uncover the presence of water channels in mammalian red blood cell plasma membrane by determining the effect of tetraethylammonium chloride on the water permeability of mammalian RBC plasma membrane.

Pre-Laboratory Questions

1. Why do bacterial cultures need to be incubated, usually for at least 24 hours, before we can see evidence of bacterial growth that can be observed with the unaided eye?

2. In what ways are the media used in this investigation selective?

3. In what ways are the media used in this investigation differential?

4. Consider a mixture of bacterial species from the same genus, such as Staphylococcus. Some members of this genus are harmful pathogens, while others are not. Would a selective medium alone be a good tool to separate the harmful species from the non-harmful species? Explain your answer.

Post-Lab Questions

1. Would simply adding a pH indicator like phenol red to a general-purpose medium, such as nutrient agar, result in a medium that is selective, differential, both, or neither? Why or why not?

2. Why were you instructed to inoculate each plate with three separate streaks, one of each bacterial species, instead of combining all three species and streaking them all onto the plate together?

3. Blood agar and chocolate agar are commonly-used media in many clinical and research laboratories. Why do you think they were not included in your kit?

4. Were there any discrepancies between what you saw in your experiment and what you expected to see based on the lab manual and your readings in this section?

BIOL 382 Lecture Notes - Lecture 1: Aplastic Anemia, Sodium Chloride, Hemoglobin

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