2006 - Question 6.
A 33 year old man considers that he is overweight (BMI = 27) and, in an effort to “trim the waistline”, is running about 4 km each evening after work. He runs at a moderate pace, well within his aerobic capacity. Outline the pathways for utilising fat and “trimming the waistline” in this scenario. In your answer include a description of control mechanisms which are relevant in stimulating utilisation of fat to sustain exercise. (It is not necessary to give details of hormone signal transduction mechanisms.)
(15 marks)

 

2007 - Question 6.
AMP Kinase has been suggested to be a “master switch” responding to energy status in cells. Describe how
AMP Kinase senses energy status in cells and two ways in which this enzyme controls availability of fuels
for energy generation in muscle cells.
(6 marks)

 

2008 - Question 5.
a) After a meal, one action of insulin in a normal person is to promote uptake of glucose into adipose tissue cells. Outline the pathway after uptake of glucose into adipocytes which leads to formation of fatty acids (subsequently stored as triacylglycerol [TAG]).
(5 marks)
b) In obese people, the ability of insulin to stimulate glucose uptake to adispose tissue or muscle is frequently impaired. Give an overview or outline of the mechanism by which insulin stimulates glucose uptake in these cells (full details not required). Then suggest mechanisms which contribute to resistance or insensitivity to this action of insulin in obese people.
(8 marks)

 

c) i. Identify two physiological circumstances in which the TAG stored in adipose tissue is broken down to yield fatty acids for use in the body. What is the main signal triggering TAG breakdown in each circumstance?
(3 marks)
ii. What is the major use of the fatty acid that is released ?
(2 marks)