Urinalysis and BCA Protein Assay: Techniques, Analysis, and Interpretation

What am I required to do in this assignment?

You must provide short answers containing at least six sentences to the following questions. You must use scientific textbooks and scientific research papers to reference your report.

1. Urinalysis is a technique involving physical, chemical and microscopic analyses of a sample of urine. Table 1 describes the physical and chemical properties of five samples of patients’ urine.
a) Which sample represents a healthy patient? Explain and reference your answer
b) Which of these patients is diabetic? Explain and reference your answer

Table 1: Descriptions of five urine samples Urine A Urine B Urine C Urine D Urine E
Colour Yellow Yellow Yellow Yellow Yellow
Cloudiness Not cloudy Not cloudy Not cloudy Not cloudy Not cloudy

Ketones Negative Negative Negative Negative Strongly

Submission Deadline Marks and Feedback

Unit learning outcomes 1. Identify and describe the gross and microscopic structural properties of various body systems and relate these to their respective functions.
2. Demonstrate skills in data analysis, reporting, and information literacy in a scientific/clinical context to evaluate the interrelationship of the structure and function of various organs.

Blood Trace Negative Trace Negative Negative

2. The bicinchoninic acid (BCA) protein assay enables the quantification of protein by measuring the absorbance of a BCA : protein complex at 562nm. Below is a table containing absorbance readings at 562 nm for standard protein samples of known protein concentrations.

Absorbance readings at 562 nm for six standard and two test samples

a) Calculate the mean absorbance reading for each sample (standards 1 – 6 and test samples 1 and 2). Show all your working and present your data in table format.
b) Calculate the normalized absorbance reading for each standard sample by subtracting the mean value for sample 6 from each sample’s mean value. Show all your working and present your data in table format.
c) Why is it necessary to subtract the mean value for standard 6 from each sample’s mean absorbance reading?
d) What happens to the absorbance values at 562 nm as the protein concentration of the standard samples increases?
e) Why are you measuring the absorbance of these samples at 562 nm and not 280 nm? Reference your answer

3. Plot a graph where the x-axis represents Protein Concentration (μg / ml) and the y-axis represents Normalized Absorbance values at 562nm. Work out the equation for the line of best fit.
4. Using the equation of the line of best fit, calculate the concentrations of proteins in test samples 1 and 2. Show all your working.
5. During normal digestion what is the location and function of the enzyme salivary amylase? Reference your answer
6. What pH and temperature does salivary amylase function at? Reference your answer
7. Experimentally the presence of starch is determined using the Lugol’s test and the appearance of maltose is determined by the Benedict’s test. Four solutionswere tested for the presence of starch and maltose using these tests. The results are listed in table 3. For the Benedict’s test a blue colour indicated the absence of maltose

 a green colour indicates the presence of a tiny amount of maltose
 a yellow colour indicates the presence of some maltose
 a red colour indicates the presence of a lot of maltose For the Lugol’s test a purple – black colour indicates the presence of a lot of starch
 a purple – blue colour indicates the presence of a small amount of starch
 a yellow – orange indicates the absence of starch Using this information deduce which tube(s) contained the most starch following incubation?

Which tube(s) contained the most maltose?
What conclusions do you draw from these results?
What was the purpose of carrying out the Lugol’s and Benedict’s tests in the presence of water?

Blue Red Orange Yellow

What do I need to do to pass? (Threshold Expectations from UIF)
• Produce a scientific report according to expectations described in the assignment brief.
• Demonstrate the ability to analyse data obtained from laboratory practical sessions to relate physiological data to diagnostics.
• Demonstrate a basic understanding of the application of laboratory testing to physiological functions.

How do I produce high quality work that merits a good grade?

A high quality lab report, should
• contain a title page giving the assessment title, unit code, assessment number, your student number and your final word count (excluding references)
• be created electronically using Microsoft WORD. A high quality report will not include photographs of hand drawn graphs, but will contain graphs created electronically using Excel
• have completed all ten questions outlined above
• contain appropriately labelled tables and figures referred to in the main text
• show all numerical working for question 2

How does this assignment relate to what we are doing in scheduled sessions?

This assignment is based on material covered in the urinary and digestive systems lectures and tutorials.