in the we had already done lab and result is also ready. all the result and requirement will provided base on that picture you need to write lab report.
Here is the example of lab report format. Biology 1406 Lab Report 2: Selective Permeability of Membranes
Name: Student X
Lab Instructor: Name of Lab Instructor X Introduction This lab exercise is intended to study selective movement of substances through selective permeable membranes. Osmosis occurs when water passes through a semi-permeable layer from a high to low concentration gradient to reach equilibrium. Diffusion, on the other hand, allows the movement of molecules from high concentration to low concentration.
Hypothesis: If molecules are too large then they won’t be able to move across the selectively permeable membrane.
Materials and Methods
In this experiment, selectively permeable dialysis tubing is used to demonstrate movement of substances through cellular membranes. The dialysis tubing allows passage of some molecules and obstructs others.
The following materials were used to conduct the experiment:
1 25-cm length of dialysis tubing, soaking in dH2O
Two 10-cm pieces of string
Bottle of 1% soluble starch in 1% sodium sulfate
Dishpan half-filled with dH2O
400-mL graduated beaker
Ring stand and funnel apparatus
Bottle of 1% albumin in 1 % sodium chloride
8 test tubes
Test tube rack
China marker
Iodine solution in dropper bottle
2%barium chloride reagent in dropper bottle
2% silver nitrate reagent in dropper bottle
Biuret reagent in dropper bottle
Scissors
25ml Beaker
Disposable pipettes
LAB REPORT EXAMPLE
Pictures/drawings of the Setup (If required by instructor)
Procedure:
1. Soak the 15cm dialysis tubing in dH2O
2. Obtain a section of the dialysis tubing that has been soaked in dH2O
3. Fold over and tie the end of the tubing with string to form a leak-proof bag.
4. Slip the other end of the bag over the stem of a funnel.
5. Fill the bag with 10ml of the solution of 1% soluble starch in 1% sodium sulfate.
6. Remove the bag, fold over and tie the open end.
7. Rinse the tied bag in a dishpan filled with dH2O
8. Pour 200 ml of a solution of 1% albumin in 1% sodium chloride into the beaker
9. Put the bag into the beaker.
10. Label 8 test tubes 1-8.
11. After 60 minutes, dispense 5 ml of the beaker’s contents into test tubes (1-4).
12. Rinse the dialysis bag in the dishpan of dH2O. Cut the bag with scissors and pour
the contents into a 25mL-beaker cylinder. Pipette 5-ml into each of the remaining
4 test tubes (5-8).
13. Perform tests below for starch, sulfate ions, chloride ions, and protein in test
tubes 1-4. Record results in Table 1. Repeat tests below for test tubes 5-8.
Record results in Table 2. (The results tabulated as shown in the table below.)
Test for Starch add 3-5 drops of iodine solution to test tube 1 & 5. A blue/black color
change indicates the presence of starch.
Test for Sulfate ion add 3-5 drops of 2% barium chloride to test tube 2 & 6. A white
precipitate of barium sulfate indicates the presence of sulfate ions.
Test for Chloride ion add 3-5 drops of 2% silver nitrate to test tube 3 & 7. A milkywhite
precipitate of silver chloride indicates the presence of chlorine ions.
LAB REPORT EXAMPLE
Test for Protein add 3-5 drops of biuret reagent to test tube 4 & 8. A change in color
from blue to violet indicates the presence of protein.
Results
The contents of the beaker after 25 minutes tested positive for sulfate ions. The
contents of the beaker tested negative for starch (Table 1). The contents of the dialysis
bag after 25 minutes tested positive for chloride ions. The contents of the bag tested
negative for albumin (Table 2).
Table 1: Test Results for Substances in Beaker
Substances
Start of Experiment
After 25 minutes
Starch – –
Sulfate ion – +
Chloride ion + +
Albumin + +
Contents of Beaker: (+) = presence, (-) = absence
Table 2: Test Results for Substances in Dialysis Bag
Substances
Start of Experiment
After 25 minutes
Starch + +
Sulfate ion + +
Chloride ion – +
Albumin – –
Contents of Dialysis: (+) = presence, (-) = absence
Figure 1. Results of tests on beaker solution Figure 2. Results of tests on bag solution
(Test tubes 1-4). (Test tubes 5-8).
LAB REPORT EXAMPLE
Discussion
According to the results, the hypothesis can be supported. The experiment
demonstrated that the selectively permeable pores on the dialysis tubing are very small
and do not allow large molecules such as starch and albumin to pass through. The
pores allow the smaller ions such as sulfate and chloride ions to pass through the
selectively permeable membrane.
(If experiment results do not accurately support your hypothesis, then list any potential
source of error that could have occurred. For example, the bag was not left in the
beaker solution for the correct amount of time.)
References
Any source material used should be cited appropriately. See example below.
Mazan MR, Hoffman AM. 2001. Effects of aerosolized albuterol on physiologic
responses to exercise in standardbreds. Am J Vet Res. 62(11):1812–1817.