Please read the ‘lab manual general guidelines’ document on myelearning for general instructions on how to write up the lab.
Here are some pointers for this particular lab.
Name of lab partner
Date: The date you did the lab
Aim: Be very specific – what were you measuring? Name of enzyme. What was the source of the enzyme?
This is a year 2 lab. You don’t have to define what is an enzyme or show how it works. Focus on the enzyme you are working with.
All enzymes will have an EC number. Start there.
What information does the digits in the EC number give?
Where in the body is the enzyme located? – organ as well as subcellular level.
State its reaction.
Show that it is part of the urea cycle.
Describe the principle of the assay used – rxn of urea with INPP. Show structures.
NOTE: You don’t have to talk about common laboratory equipment such as the spectrophotometer
Methodology and materials
- Materials/reagents must be listed with their concentrations (where possible); equipment/glassware not necessary
- Summary of method – continuous prose. NO POINT FORM
- Past tense
The full method has to be given. Don’t say ‘ as seen in the manual’. You are expected to be able to use the method in your lab report and be able to do the lab without referring to the manual.
You must state your actual results. If there is something wrong with your values then you can go see Ms Fariyal and get some theoretical results to do your calculations. You will have to examine in your discussion why you think your results deviated from what was expected.
Number and title your tables and graphs.
In addition to the table for your calibration curve you will want to tabulate your results for the 2 mixtures.
For your calibration curve – state a title, clearly labeled axes, give a scale and it’s the best straight line through the origin. You can draw your graph on excel. Just set it up so that the straight line passes through the origin and get an equation of the line from excel so that you could work out the amount of urea in your samples.
This was discussed during your lab session.
Don’t forget to calculate your corrected absorbances.
In addition you are required to do up a flow chart for your calculations. This is NOT the flow chart you did for your lab session that broke down the procedure. This flow chart is different and shows all the dilutions and aliquots taken. This will let us know that you properly understood what you did in your calculations. So you will start with the liver giving its mass and work you way down to the final aliquot. Stating volumes along the way.
Compare your results obtained with other theoretical/experimental results.
Discuss how enzyme activity is measured and compare these techniques with the one you did for this lab.
State sources of error and precautions taken for this expt.
Why was the liver extract kept cold?
Why was the reaction carried out at 37oC ?
Why was MnSO4 used?
Why were the tubes foiled?
The use of perchloric acid.
Use proper format as outlined in the Chicago manual of style 16th edition doc on myelearning.
Your information in the introduction and discussion must be cited and a list of your references given in alphabetical order at the end.
Diagrams and figures reproduced must be referenced.
Other things to note:
Remember its mL not ml
Attached a signed accountability statement form to your lab.
Submit your lab a week from when the lab was done. You are to submit your lab by 3:30pm to the biochem office Rm 217 in the old Nat Sci wing.
Submit your introduction and discussion in a word document to the Turnitin link on myelearning. This should be obvious but you will need to submit the same intro and discussion that you submitted from your hard copy to Turnitin. Failure to submit to Turnitin will result in loss of marks.
Plagiarism will result in the loss of marks and depending on the level of plagiarism you will get a zero grade and reported to the UWI examinations board.
Please direct all your questions to Ms Fariyal concerning the lab.