Parts 1-6 on Insendi Flashcards
Two key features of brain metabolism?
Requires a continuous supply of glucose and brain cannot metabolise fatty acids (can metabolise some ketone bodies)
Two glucose conditions?
- Hypoglycaemia- too little glucose and causes faintness and coma
- Hyperglycaemia- too much glucose, can cause irreversible damage
3 key features of heart metabolism?
- Heart must beat constantly so it is designed for completely aerobic metabolism
- Utilises TCA cycle substrates e.g free fatty acids and ketone bodies
- Loss of O2 leads to cell death and myocardial infarction
3 liver metabolic features?
- Undergoes wide repertoire of metabolic processes
- Storage organ (glycogen)
- Plays a key role in lipoprotein metabolism
Pentose phosphate pathway?
Glucose-6-phosphate used to produce nucleotides and generate NADPH for anabolic pathways
3 things the body does during a hypoglycaemic coma?
- Breakdown glycogen in the liver
- Releases FFA from adipose tissue
- Converts acetyl CoA into ketone bodies via the liver
How many reactions in gluconeogenesis are irreversible and have to be bypassed?
3 (hexokinase, phosphofructokinase and pyruvate kinase are the enzymes)
4 additional enzymes needed for gluconeogenesis?
Pyruvate carboxylase, phosphoenolpyruvate carboxykinase, fructose-1,6- biposphatase and glucose-6-phosphatase
Why are the 4 ‘additional’ high energy bonds needed in gluconeogenesis?
To turn an energetically unfavourable process into an energetically favourable one
Glucogenic amino acids?
Skeletons can give rise to glucose via gluconeogenesis
Ketogenic amino acids?
Cannot enter gluconeogenesis but can be used to synthesise fatty acids and ketone bodies
What can glycerol be converted into?
DHAP to enter the gluconeogenic pathway upstream