Blood sugar levels 

• glucose is required for cell respiration
• glucose must be present in the blood at all times
• the levels have to be kept within certain limits to prevent damage to the body
• too high or low you may die

control of blood glucose

• 2 hormones control glucose levels
• insulin and glucagon
• these are released from the islets of Langerhans
• alpha cells release glucagon
• beta cells release insulin

rise in glucose levels

• absorption of carbohydrates such as starch and sugars after a meal
• starch is broken down into glucose before absorption
• glucose is absorbed by the small intestine
• blood glucose levels will rose

response to rise in glucose levels

• conversion of amino acids to glycerol and glucose.excess amino acids absorbed from food cannot be stored,they are deaminated in the liver
• the amino part is converted into urea and excreted.the rest of the molecule is converted into glucose
• conversion of glycogen into glucose

effects of insulin

• released when glucose levels rise
• target cells are liver and muscle
• cause these cells to take up glucose by increasing their membrane permeability by adding more transport proteins to the membrane
• glucose uptake is by facilitated diffusion
• stimulate the cells to produce an enzyme that converts soluble glucose into insoluble glycogen
• the glycogen will act as a glucose store
• as a result blood glucose levels fall
• they are stored as glycogen rather than glucose so that the balance of the cell is not disturbed

effects of insulin

• increases the rate of respiration to lower glucose levels

• increases the rate of conversion of glucose into fat in adipose cells

  %%⭐ blood glucose rises → detected by beta cells → beta cells release insulin → blood glucose levels fall to normal → detected by beta cells → reduce insulin production.%%

effects of glucagon

• released when glucose levels fall
• target cells are liver cells
• cause cells to produce an enzyme that converts glycogen to glucose
• gluconeogenesis
• causes the cells to release the glucose into blood
• glucose levels in the blood will rise - bringing it back to normal

%%⭐ blood glucose levels fall → detected by the alpha cells → alpha cells release glucagon → blood glucose levels fall to normal → detected by alpha cells → reduce glucagon production%%

\