Complete Table 2.2 to indicate the correct order in which these events happen. Three of the events have already been placed correctly.
An investigation was done to measure the rate at which glucose is supplied for respiration from three different glucose sources: a meal; glycogenolysis - the breakdown of glycogen; gluconeogenesis - the production of glucose from non-carbohydrate molecules. After a person had eaten a meal, the rates at which glucose was supplied for respiration from the three sources were measured at regular intervals over a $24$-hour period. No food was eaten during this period. Fig. 2.1 shows the results of this investigation.
State the time after the meal when the rate of glucose supplied from the meal for respiration was equal to the rate of glucose supplied from glycogenolysis for respiration.
State the earliest time after the meal when all of the glucose for respiration came from gluconeogenesis.
Name the homeostatic mechanism that keeps blood glucose concentration at a set point.
In humans, carbohydrates such as glucose are not the only respiratory substrates. Name two non-carbohydrate respiratory substrates in humans.