Lab: Blood Exploration (Page 5 of 6) in pdf

PART C: Investigating the Buffering Capacity of Blood

1. Obtain 20mL of non-buffered blood solution in a 100mL beaker.

2. Using tweezers, pick up a strip of pH paper. Dip the pH paper in the blood, remove the strip

promptly, and match to the pH value on the tube. Record the value in the data table.

3. Your blood sample already has a buffer in it. Add 5 drops of HCl (acid solution) to your blood

solution, and re-test the pH using a new strip pH paper. Record the value in the data table.

4. Add 5 more drops of HCl to your blood solution, re-test the pH, and record the value in the

data table.

5. Add another 5 drops of HCl to your blood solution, re-test the pH and record the value in the

data table.

6. Add 10mL of HCl to your blood solution, re-test the pH and record the value in the data table.

7. Rinse your beaker thoroughly, dry, and repeat steps 1-6 with the buffered blood solution.

pH of Non-Buffered

pH of Buffered

Blood Solution

Initial

After 5 drops

After 10 drops

After 15 drops

After 10mL + 15 drops

Analysis Questions

PART A

1. Draw the “normal” shape of an RBC. Why is this form important for its function? Be specific.

2. Compare and contrast the shape of the red blood cells observed in the normal human blood

smear, the sickle cells smear, the frog blood smear, and the dolphin blood smear. Note any

structural differences observed.

3. Sickle cell is actually an autosomal recessive trait. This means one must inherit two defective

recessive alleles (one from each parent) to display the disease. However, being heterozygous

for the sickle cell trait has been shown to increase an individual’s resistance to the disease

malaria (carried by mosquitos, common in Africa). If two parents, each heterozygous for the

sickle cell trait, have an offspring, what is the probability the child will be born with sickle cell

disease? Show a Punnett square with your answer. Use “H” as the dominant allele and “h”

as the recessive, sickle allele.

Lab: Blood Exploration Page 5