Control of blood glucose concentration Flashcards
What is hyperglycaemic?
Lots of sugar = H2O removed
What is hypoglycaemic?
Not enough sugar = energy deprived from cells
Where does glucose come from?
Diet
Glycogenolysis
Glycogenesis
Gluconeogenesis
What is glycogenolysis?
Breakdown of glycogen to glucose
What is glycogenesis?
Formation of glycogen from excess glucose
What is gluconeogenesis?
Production of glucose
What is the glucose made from produced in gluconeogenesis?
Glycerol + amino acids (liver)
Why is the pancreas important?
Produces digestive enzymes
Produces hormones
What does the pancreas contain?
Islets of Langerhans
What hormones does the pancreas produce?
Insulin
Glucagon
What does glucagon do?
Increase blood sugar levels
What does insulin do?
Decrease blood sugar levels
What are the Islets of Langerhans?
Hormones producing cells
Beta + alpha cells
Which cells produce glucagon?
Alpha cells
Which cells produce insulin?
Beta cells
How do the islets of Langerhans work?
Antagonistically
What is the second messenger model used by?
Non lipid-soluble hormones
What does the second messenger model initiate?
Response inside of cells
What happens in second messenger model?
Adenylate cyclase activated
Converts ATP to cyclic AMP
cAMP activates kinase enzyme
Glycogenolysis occurs
Describe how insulin reduced the conc of glucose in the blood
Beta cells detect increased conc
Insulin secreted
Insulin binds to glycoproteins on cell surface membrane
Alters tertiary structure of glucose channel
Activates carrier proteins to open glucose channel
Increased permeability of muscle
Glucose is converted to glycogen (glycogenesis)
BLOOD SUGAR LEVELS DECREASE
Describe how glucagon increases conc of glucose in the blood
Alpha cells detect drop in glucose conc
Secrete glucagon
Only liver cells have glucagon receptors
Activates kinase enzyme = glycogenolysis + gluconeogenesis
Glucose released
BLOOD SUGAR LEVELS INCREASE
How does insulin control rely on antagonistic + negative feedback mechanisms?
Corrective mechanism
Glucagon + glucose act oppositely
What can diabetes be called?
Mellitus
What happens with diabetes?
Cannot metabolise carbohydrates effectively
What is Type 1?
Insulin dependant
What is Type 2?
Insulin independent
When does Type 1 happen?
Early onset
When does Type 2 happen?
Often correlated with obesity
How can Type 1 be treated?
Insulin injections
Regulated/monitored using biosensor
How can Type 2 be treated?
Monitoring carbohydrate intake + exercise
What happens in Type 1 diabetes?
Immune system attacks beta cells
What happens in Type 2 diabetes?
Produce insulin but cells don’t respond
Glycoproteins receptors lose responsiveness to insulin
Does Type 1 produce insulin?
NO
Why wouldn’t you transplant the pancreas of someone with Type 2 diabetes?
As still produce insulin
But cells don’t respond
What are symptoms of diabetes?
High blood glucose levels Glucose in urine Thirst + hunger Urinate frequently Weight loss
What do some people with diabetes gain blurred vision?
As shape of lens changes
Affects nerves = poor blood circulation
Why do people with diabetes produce glucose in urine?
Glucose cannot be reabsorbed
Why do people with diabetes get thirsty + hungry?
Decrease water potential = more H2O lost
Why do people with diabetes urinate frequently?
Lack of glucose
Why do people with diabetes get very tired?
Low respiratory rate
Why do people with diabetes lose weight?
Less glucose = less energy for growth + repair = cells start to break down
