lecture 12 - integrated metabolism

Question 1

why do cell processes need to be controlled?

Answer 1

• Each cell has potential for carrying out many different chemical reactions/pathways
• Many are conflicting in purpose
• Co-ordinate metabolic activities within a cell
• Cells do not work as individuals
• Co-ordinate (integrate) metabolic activities of cells in different parts of the organism
• Enable efficient utilisation of metabolites to meet current needs of the organism

Question 2

how are metabolic activities controlled in different ways?

Answer 2

Hormonal control
Substrate supply
Allosteric enzymes
Nervous control

Question 3

what are the major metabolic processes for adipose tissue?

Answer 3

carbohydrate metabolism (TCA cycle)
,lipid metabolism (FA synthesis, lipolysis)

Question 4

during adipose tissue what is broken down for energy production to produce glycerol?

Answer 4

glucose

Question 5

what are the major metabolic processes for muscle tissue?

Answer 5

carbohydrate metabolism, lipid metabolism, protein metabolism (protein synthesis/degradation)

Question 6

what are the major metabolic processes for liver tissue?

Answer 6

carb metabolism, lipid metabolism, protein metabolism (transasmination/deamination, urea cycle)

Question 7

what are the 3 major hormones in control of energy metabolism in the tissues?

Answer 7

insulin (adipose), glucagon(liver), adrenaline(muscle)

Question 8

when adding a phosphate group to an enzyme what does it do?

Answer 8

switches it off (decreasing binding activity) or activates it (increasing binding activity)

Question 9

what is the overall effect of insulin?

Answer 9

• glycogen synthesis and FA synthesis is turned on
• glycogen degradation and lipolysis is turned off

Question 10

what does PP1 do in relation to glycogen phosphorylase?

Answer 10

deactivates it - inhibits the breakdown of glycogen into glucose

Question 11

what is the overall effect of glucagon?

Answer 11

• glycogen degradation, lipolysis and gluconeogenesis is turned on
• glycogen synthesis and glycolysis is turned off
• glucose is released from liver into blood

Question 12

what is the overall effect of adrenaline?

Answer 12

• glycogen degradation and lipolysis is turned on
• glycogen synthesis is turned off
• Glucose released from liver into blood but in muscle used for glycolysis, not released into blood