PSL300H1 Lecture Notes - Lecture 6: Anabolism, Alpha Cell, Exocrine Gland
Lecture 6 notes
• Insulin
o Hormone made by the pancreas specialized cells called beta cells, it takes glucose and
puts it in to the cells
o Prevents hyperglycaemia
o Stimulates by high glucose, GLP1, PNS
o Decreases blood glucose, and heavily involved in growth, promotes anabolic pathway
• Glucagon
o Prevents low blood sugar in the body, hypoglycaemia
o Alpha cells in pancreas secrete glucagon in response to low blood sugar
o It takes glycogen from the cells and breaks it down in to glucose for use
• GLP-1
o Stimulates insulin secretion, increases beta cell mass
o Released from intestine
o Decreases our appetite and glucagon
• Metabolism
o Sum of all chemical reactions in the body
o 2 states
▪ Fed, absorptive, anabolic, (insulin)
▪ Fasted, post absorptive, catabolic, (glucagon)
o Basil metabolic rate BMR
▪ An individuals energy expenditure when resting
▪ On the diagram any left side to the right side, it is anabolic, insulin (building up
larger molecules from smaller; glucose to glycogen)
• Insulin takes glucose and puts it into the cell making glycogen, process
called glycogenesis
• All going to the left side of the diagram are catabolic
o Breaking down larger molecules to make energy
o Glucagon takes glycogen and breaks it down in to glucose
• Pancreas
o 98% of it is an exocrine gland
▪ Majority will make enzymes that will be put into the small intestine to facilitate
digestion
o 2% is called the Islet of Langerhans
▪ Made of beta cells, delta cells, and alpha cells that secrete endocrine hormones
▪ Beta cell releases insulin that binds to a receptor-enzyme complex to signal
secondary messenger system, phosphorylating proteins triggering cell response
▪ Alpha cell releases glucagon that binds to G protein-coupled receptor to trigger
secondary messenger systems phosphorylating proteins and triggering cell
response
