Question 1: Blood glucose levels are tightly regulated in the human body to maintain homeostasis. The hormones insulin and glucagon play key roles in lowering or raising blood glucose levels respectively, ensuring they stay within a healthy range.

Answer: Insulin lowers blood glucose by promoting its uptake into cells, while glucagon raises blood glucose by stimulating its release from the liver.

Question 1: Define the term 'homeostasis'.

Answer: Homeostasis is the maintenance of a stable internal environment despite changes in external conditions.

Question 2: Describe how insulin and glucagon work together to regulate blood glucose levels.

Answer: Insulin decreases blood glucose by increasing uptake into cells and storage as glycogen, whereas glucagon increases blood glucose by stimulating glycogen breakdown and glucose release from the liver.

Question 1: If a person's blood glucose level is measured at 5 mmol/L and the total blood volume is 5 litres, calculate the total amount of glucose (in milligrams) present in their blood. (Use the molar mass of glucose = 180 g/mol).

Answer: 450 mg

Question 2: A diabetic patient has a fasting blood glucose level of 8 mmol/L. If the normal range is 4-7 mmol/L, by what percentage is the patient's blood glucose level above the upper normal limit?

Answer: 14.29%

Question 1: Describe a simple experiment to test how insulin affects blood glucose levels in a laboratory setting. Include the key variables and safety precautions.

Answer: The experiment involves taking blood samples from a controlled group, administering insulin to one sample, and measuring glucose levels before and after. The independent variable is insulin concentration; the dependent variable is blood glucose level. Variables to control include sample volume, temperature, and timing. Safety precautions include handling insulin carefully, wearing protective gloves, and proper disposal of biological samples.

Question 1: A patient’s blood glucose readings over a day are: 4.5 mmol/L (morning), 9.0 mmol/L (after meal), 5.2 mmol/L (evening). Explain what these readings suggest about the patient’s blood glucose regulation and possible health condition.

Answer: The readings indicate normal fasting levels but a significant rise after a meal, suggesting normal insulin response. However, if the post-meal level remains high consistently, it could indicate impaired glucose tolerance or diabetes. Overall, the data should be compared with normal ranges to assess regulation efficiency.

Question 1: How do insulin injections help people with Type 1 diabetes? Explain the biochemical process involved.

Answer: Insulin injections provide the hormone externally to help regulate blood glucose levels, enabling glucose uptake into cells and preventing hyperglycaemia, by mimicking natural insulin action on receptors in cell membranes.

Question 2: Discuss one technological advancement that improves blood glucose monitoring for diabetics.

Answer: Continuous glucose monitors (CGMs) allow real-time tracking of blood glucose levels, providing alerts for high or low readings, and improving management of diabetes.