Diabetes - Science Flashcards
What do A cells secrete?
Glucagon
What do D cells secrete?
Somatostatin
What do PP cells secrete?
Pancreatic polypeptide
Which part of B cells is insulin synthesised?
RER
Which peptide is the by-product of insulin product and why is it useful?
C-peptide
Can be measured to help determine insulin levels
Which 2 proteins make up a Katp channel?
Kir
SUR1
An overactive Katp channel results is which condition?
Diabetes
Which condition results from inactive Katp channels?
Hyperinsulinaemia
What kind of receptor is the insulin receptor?
Dimerise tyrosine kinase
Which part of the insulin receptor does insulin bind to and which part phosphorylates?
Insulin attaches to alpha subunit
Beta subunit phosphorylates
What are the biological effects of insulin?
Amino acid uptake in muscle
DNA synthesis
Protein synthesis
Growth responses
Glucose uptake in muscle & adipose tissue
Lipogenesis in adipose tissue & liver
Glycogen synthesis in liver & muscle
Gene expression
Lipolysis
Gluconeogensis in liver
What to B cells secrete?
Insulin
Mechanism of insulin secretion
Glucose enters B cells through GLUT2 and is phosphorylated by glucokinase
Increased metabolism of glucose leads to increased intracellular ATP production
ATP inhibits Katp channels
Inhibition of Katp channels depolarises the cell membrane
Depolarisation of the membrane leads to the open of Ca2+ channels
Increase in internal Ca2+ leads to fusion of secretory vesicles with the cell membrane and release of insulin
Where are ketone bodies formed?
Liver mitochondria
How are ketone bodies produced?
Derived from acetyl-CoA from Beta oxidation
