control of blood glucose Flashcards
what is normal blood glucose levels usually around
90 mg per 100g of blood
what monitors blood glucose concentration
pancreas
when does blood glucose conc rise
after eating food containing carbs
when does blood glucose conc fall
after exercise
why does blood glucose conc fall after exercise
glucose is used up in respiration
what do insulin and glucagon act as
effectors
what is the role of insulin
lowers blood glucose concentration when it is too high
what receptors does insulin bind to
specific receptors on liver and muscle cells
how does insulin increase blood glucose concentration
increases permeability of cell membranes to glucose so they take up more glucose
activates enzymes which convert glucose to glycogen
what is the term for converting glucose to glycogen
glycogenesis
what is the role of glucagon
raises blood glucose concentration when it is too low
where does glucagon bind to
specific receptors on liver cells
what does glucagon activate
enzymes the breakdown glycogen into glucose
what is the process of breaking down glycogen called
glycogenolysis
what does glucagon also use to create glucose
glycerol and amino acids
what is the process of forming glucose from non carbs called
gluconeogenesis
what does glucagon decrease the rate of in cells
respiration
what keeps blood glucose levels normal
negative feedback loop
when blood glucose levels are high, what happens to beta cells
more glucose enters them via facilitated diffusion
what does more glucose in beta cells cause
the rate of respiration to increase making more ATP
what does the increase in ATP cause
potassium ions in beta cells to close, so they build up inside of the cell
what does the build up of potassium ions in the beta cells cause
inside of the beta cell is less negative so that it is depolarised
what does depolarisation of beta cells trigger
calcium ion channels to open, calcium ions diffuse into the cell
what does the movement of calcium ions inside of the beta cells cause
vesicles to fuse with the plasma membrane releasing insulin via exocytosis
