Blood Glucose Regulation Lab Report

LABORATORY REPORT Activity: Blood Glucose Regulation Predictions 1. Plasma glucose levels will be highest 1-3 hours after the meal 2. Plasma ketone levels will be highest before the meal (fasting) 3. Plasma insulin levels will be highest immediately after the meal (0 hr) 4. Plasma glucagon levels will be highest immediately after the meal (0 hr) Materials and Methods 1. Dependent Variable plasma levels of glucose, ketones, insulin, and glucagon 2. Independent Variable food and beverage intake 3. Controlled Variables physical activity, caffeine and alcohol intake, gender, age, BMI 4. Why were physical activity and caffeine and alcohol intake the controlled variables? Physical activity, caffeine and alcohol effects plasma levels of glucose, ketones, insulin, and glucagon. 5. What type of assay was used to measure plasma glucose and ketone levels? Enzymatic analysis was used to measure plasma glucose and ketone levels. 6. What type of assay was used to measure plasma insulin and glucagon levels? Radioimmunoassay was used to measure insulin and glucagon levels. Results Table 2: Glucose and Ketone Concentration in Blood Plasma Fasting Immediately post meal I hr post meal 2 hr post meal 3 hr post meal Sub. 1 5.3 6.5 6.4 5.5 4.7 Glucose (mmol/l) Sub. 2 Sub. 3 5.3 5.3 6.4 6.4 6.2 5.5 4.8 6.4 5.6 4.6 average 5.3 6.4 Sub. 1 96 92 6.3 5.5 4.7 55 64 67 Ketones (µmol/l) Sub. 2 Sub. 3 100 111 108 96 69 53 61 57 55 66 average 102 99 60 57 65 Laboratory Report Glucose Concentration in Blood Plasma µmol/l 7 5.6 1. Fasting 2. Immediately post meal 3. 1 hr post meal 4. 2 hr post meal 5. 3 hr post meal 4.2 2.8 1.4 0 1 2 3 4 5 Ketone Concentration in Blood Plasma µmol/l 110 88 1. Fasting 2. Immediately post meal 3. 1 hr post meal 4. 2 hr post meal 5. 3 hr post meal 66 44 22 0 1 2 3 4 5 1. When was plasma glucose concentration highest? If values are similar for several time points (within a few points of each other), then give range of times when plasma glucose concentration was highest. Plasma glucose was highest between 0 hr post meal and 1 hr post meal. 2. When was plasma glucose concentration lowest? If values are similar for several time points, then give range of times when plasma glucose concentration was lowest. Plasma glucose concentration was the lowest at the 3 hr post meal. Glucose concentration was not much higher when in the fasting stage of experiment. 3. When was plasma ketone concentration highest? If values are similar for several time points, then give range of times when plasma ketone concentration was highest. Plasma ketone concentration was highest in between fasting and 0 hr post meal. 4. When was plasma ketone concentration lowest? If values are similar for several time points, then give range of times when plasma ketone concentration was lowest. Ketone concentration was lowest during hours 1 and 2 post meal marks. Table 3: Insulin and Glucagon Concentration in Blood Plasma Insulin (pmol/l) Fasting Immediately post meal I hr post meal 2 hr post meal 3 hr post meal Glucagon (pmol/l) Insulin / Glucagon Ratio Sub. 1 60 96 Sub. 2 65 98 Sub. 3 69 77 average 65 90 Sub. 1 37 35 Sub. 2 33 34 Sub. 3 36 37 average 35 35 172 129 181 122 175 139 176 130 29 34 28 34 32 36 30 35 5.9 3.7 72 68 56 65 36 34 35 35 1.9 1.9 2.6 Laboratory Report Insulin and Glucagon Concentration in Blood Plasma pmol/l 180 144 1. Fasting 2. Immediately post meal 3. 1 hr post meal 4. 2 hr post meal 5. 3 hr post meal 108 72 36 0 1 2 3 4 5 Insulin to Glucagon Concentration Ratio 6 4.8 1. Fasting 2. Immediately post meal 3. 1 hr post meal 4. 2 hr post meal 5. 3 hr post meal 3.6 2.4 1.2 0 1 2 3 4 5 1. When was plasma insulin concentration highest? If values are similar for several time points, then give range of times when plasma insulin concentration was highest. Insulin concentration was highest 1 hour post meal. 2. When was plasma insulin concentration lowest? If values are similar for several time points, then give range of times when plasma insulin concentration was lowest. Insulin concentration was the lowest when fasting (65) and then dropped back down to 65 again at the 3 hr post meal mark. 3. When was plasma glucagon concentration highest? If values are similar for several time points, then give range of times when plasma glucagon concentration was highest. Glucagon concentration was the highest at fasting, 0 hr, 2 hr, and 3 hr post meal marks; all measuring at 35. 4. When was plasma glucagon concentration lowest? If values are similar for several time points, then give range of times when plasma glucagon concentration was lowest. Glucagon concentration was lowest at the 1 hr post meal mark. 5. When was plasma insulin/glucagon concentration highest? If values are similar for several time points, then give range of times when plasma insulin/glucagon concentration was highest. Insulin/glucagon was highest at 1 hr post meal. 6. When was plasma insulin/glucagon concentration lowest? If values are similar for several time points, then give range of times when plasma insulin/glucagon concentration was lowest. Insulin/glucagon concentration was lowest when fasting and at the 3 hr post meal mark. Discussion 1. Explain how insulin changed plasma glucose concentration over the course of the experiment. When food was consumed and glucose was absorbed into the body, plasma glucose levels increase causing insulin to be released into the blood. Insulin and glucose were highest at 1 hr post meal. Insulin secretion gave a steady decrease in glucose levels at hours 2 and 3 post meal. 2. Explain how glucagon changed plasma glucose concentration over the course of the experiment. At the 3 hour post meal mark, glucagon stimulated glycogenesis and glycogenolysis to maintain plasma glucose level. Laboratory Report 3. Explain what caused the change in plasma ketone concentration over the course of the experiment. When fasting, the body starts using fat as energy creating ketones. This is why the plasma ketones were highest when fasting and before the body starting absorbing glucose 0 hrs post meal. Once the body is able to absorb glucose, it no longer needed fatty acids for energy, thus, ketone concentration dropped. 4. Explain how negative feedback caused the changes in plasma insulin concentration observed during the experiment. When plasma insulin levels rose, glucose levels dropped. When plasma glucose is low, the body no longer needs as much insulin. 5. Explain how negative feedback caused the changes in plasma glucagon concentration observed during the experiment. When plasma glucose levels dropped, glucagon increases to maintain glucose levels. Once glucose increased again, the body stops the production of glucagon. 6. The insulin/glucagon ratio changed over the course of the experiment indicating changes in glucose storage and changes in ability to increase blood glucose concentration via glycogenolysis and gluconeogenesis. State when glucose storage capability was highest and why. Insulin/glucagon ratio indicates when glucose is being stored or when the glucose is being used to maintain by glycogenolysis and gluconeogenesis. Glucose storage capability was highest at 1 and 2 hr post meal because the body was able to store glucose as it was not needed for glycogenolysis and gluconeogenesis. 7. State when glycogenolysis and gluconeogenesis were highest and why. Glycogenolysis and gluconeogenesis was highest while fasting and the 3 hr post meal mark because glucose was not readily available and was needed to maintain glucose levels. 8. Explain how a high blood ketone level helps the body conserve blood glucose. When glucose is not readily available, the body raises blood ketones levels. Ketones can be used as fuel for the body to produce energy. 9. Restate your predictions that were correct and give the data from your experiment that supports them. Restate your predictions that were not correct and correct them, giving the data from your experiment that supports the correction. *see addition submission for #9 Application 1. During exercise, epinephrine and norepinephrine are released from the adrenal medulla. Epinephrine and norepinephrine have the same effect on plasma glucose levels as glucagon. Explain how epinephrine and norepinephrine affect plasma glucose and why this is important during exercise. Epinephrine and norepinephrine stimulate glycogenolysis. Glycogenolysis increases blood glucose levels making it possible to exercise utilizing available and stored glucose. 2. The symptoms of diabetes mellitus include high plasma glucose levels and ketoacidosis (blood pH decreases due to increasing levels of ketones). Explain how diabetes causes these symptoms. When blood glucose can not get into cells, glucose levels rise. When blood sugar is high and insulin levels are low, the body starts breaking down fat for fuel because it does not require insulin. The fuel called ketones. When too many ketones build up in the system, the blood becomes acidic.