Biology 3201 Diabetes/Benedict’s Test Lab
Introduction
Diabetes is a malfunction of one of the major homeostatic mechanisms in the body – the endocrine system. Two hormones, insulin and glucagon control the level of sugar in the blood. The more glucose in the blood and surrounding fluid, the greater the amount of insulin that gets produced. The insulin is produced and released by the pancreas and is used to lower the level of glucose in the blood. This is done by causing cells to uptake (remove) glucose from the blood. If insulin levels fall and blood sugar level becomes too high, glucose in the nephrons cannot be completely reabsorbed by the cells of your body, so glucose is released in the urine. One of the earliest tests for diagnosing diabetes was to taste the urine of a potential diabetic. If it was sweet, diabetes was a probable diagnosis. In this investigation you will observe data taken from various solutions to determine if the glucose levels are high. Benedict’s solution is a reagent that changes colour in the presence of glucose. Copper ions within the reagent react with glucose molecules and form cuprous oxide. Cuprous oxide gives a colour change from green to yellow to red depending on the amount of glucose present in a sample.
Type 1 Diabetes: This form of diabetes is believed to be an autoimmune disorder in which the insulin producing cells of the pancreas are destroyed. There is no insulin production practically overnight. Without insulin, the body cannot convert excess glucose to glycogen, fat to adipose tissue and protein into muscle. Also, insulin assists in the facilitated diffusion of glucose into the cell. This means the cells essentially starve. This form of diabetes is treated with insulin.
Type 2 Diabetes: This also referred to adult onset diabetes. Ninety percent of diabetics are type 2. In this case, the body produces insulin in insufficient quantities or the body cells are unable to respond to insulin normally. This type of diabetes is treated with diet and exercise. Medications and/or insulin shots may also be necessary.
Both forms of diabetes can result in weight loss, blindness and circulatory disorders. They can be diagnosed using urine analysis and/or a glucose tolerance test.
Complete the Table in your lab using the following information
Examples are on the right they are not to be used to for the lab results go to the bottom of the page to start the lab
Solution Color - Approximate glucose concentration (percentage of solution)
Blue - Negative
Light Green - 0.15% - 0.5%
Olive green - 0.5% - 1.0%
Yellow-green to green - 1.0% - 1.5%
Orange - 1.5% - 2.0%
Red brown - 2.0% and greater
Problem: How can you use different indicators to test for blood sugar in a solution (urine)? Prediction: Predict how you can tell if sugar is present in a solution (urine).
Materials:
4 samples of unknown glucose solution.
10 mL graduated cylinder
4 test tubes
grease pencil
test tube rack
beaker clamp
test tube clamp
Benedict’s solution
500 mL beaker
hot plate
medicine dropper
Procedure: Follow the instructions on each page to complete your lab. You will have to click pictures to get to the next page as you work your way through.
Introduction
Diabetes is a malfunction of one of the major homeostatic mechanisms in the body – the endocrine system. Two hormones, insulin and glucagon control the level of sugar in the blood. The more glucose in the blood and surrounding fluid, the greater the amount of insulin that gets produced. The insulin is produced and released by the pancreas and is used to lower the level of glucose in the blood. This is done by causing cells to uptake (remove) glucose from the blood. If insulin levels fall and blood sugar level becomes too high, glucose in the nephrons cannot be completely reabsorbed by the cells of your body, so glucose is released in the urine. One of the earliest tests for diagnosing diabetes was to taste the urine of a potential diabetic. If it was sweet, diabetes was a probable diagnosis. In this investigation you will observe data taken from various solutions to determine if the glucose levels are high. Benedict’s solution is a reagent that changes colour in the presence of glucose. Copper ions within the reagent react with glucose molecules and form cuprous oxide. Cuprous oxide gives a colour change from green to yellow to red depending on the amount of glucose present in a sample.
Type 1 Diabetes: This form of diabetes is believed to be an autoimmune disorder in which the insulin producing cells of the pancreas are destroyed. There is no insulin production practically overnight. Without insulin, the body cannot convert excess glucose to glycogen, fat to adipose tissue and protein into muscle. Also, insulin assists in the facilitated diffusion of glucose into the cell. This means the cells essentially starve. This form of diabetes is treated with insulin.
Type 2 Diabetes: This also referred to adult onset diabetes. Ninety percent of diabetics are type 2. In this case, the body produces insulin in insufficient quantities or the body cells are unable to respond to insulin normally. This type of diabetes is treated with diet and exercise. Medications and/or insulin shots may also be necessary.
Both forms of diabetes can result in weight loss, blindness and circulatory disorders. They can be diagnosed using urine analysis and/or a glucose tolerance test.
Complete the Table in your lab using the following information
Examples are on the right they are not to be used to for the lab results go to the bottom of the page to start the lab
Solution Color - Approximate glucose concentration (percentage of solution)
Blue - Negative
Light Green - 0.15% - 0.5%
Olive green - 0.5% - 1.0%
Yellow-green to green - 1.0% - 1.5%
Orange - 1.5% - 2.0%
Red brown - 2.0% and greater
Problem: How can you use different indicators to test for blood sugar in a solution (urine)? Prediction: Predict how you can tell if sugar is present in a solution (urine).
Materials:
4 samples of unknown glucose solution.
10 mL graduated cylinder
4 test tubes
grease pencil
test tube rack
beaker clamp
test tube clamp
Benedict’s solution
500 mL beaker
hot plate
medicine dropper
Procedure: Follow the instructions on each page to complete your lab. You will have to click pictures to get to the next page as you work your way through.