Diabetes- glucose homeostasis

Question 1

what controls absorption use, storage, storage and circulating levels?

Answer 1

hormones

Question 2

why is glucose so important?

Answer 2

it is the only source of energy for the brain

Question 3

what is the normal blood glucose level?

Answer 3

5mM (3.4-5.8mM

Question 4

What is hyperglycaemia?

Answer 4

when blood glucose levels are too high

Question 5

what is hypoglycaemia?

Answer 5

when the blood glucose levels are too low

Question 6

how do we fuel the body?

Answer 6

by eating carbohydrates, proteins and fats then broken down in order to be absorbed

Question 7

what are the energy stores for glycogen?

Answer 7

in the liver and in skeletal muscle and it is easily available.

Question 8

what is the word for making glycogen?

Answer 8

glycogenesis

Question 9

what is the word for breaking down glycogen?

Answer 9

glycogenolysis

Question 10

what is the energy store for fats and in what form?

Answer 10

stored in the adipose tissue as triglycerides

Question 11

what is the energy store for protein?

Answer 11

skeletal muscles

Question 12

what is the word for when amino acids are converted to glucose?

Answer 12

gluconeogenesis

Question 13

what is the word given for the breakdown of protein?

Answer 13

proteolysis

Question 14

what does insulin do?

Answer 14

decrease blood glucose levels and secreted by the B-cells in the Islets of Langahans of endocrine pancreas

Question 15

what does glucagon do?

Answer 15

secreted when levels of glucose are low from the a-cells in the Islets of Langerhans

Question 16

what are the difference between cortisol and adrenaline?

purpose, … term, secreted from?

Answer 16

• both for stress
• cortisol is long term stress and adrenaline is for short term fight or fight
• both increase blood glucose and fatty acids
• cortisol is secreted from the adrenal cortex
• adrenaline is secreted from adrenal medulla

Question 17

what does somatostatin?

Answer 17

will inhibit digestion and absorption, secreted from delta cells

Question 18

what are the insulin receptors?

Answer 18

tyrosine kinase-coupled receptor

Question 19

how is insulin synthesised?

Answer 19

its synthesised like all other peptides in the ribsosmes on the RER.

• process involves the folding of it to form disulphide bonds then moves to the Golgi apparatus.
• removal of the C peptide so we are left with A chain of 21aa and B with 30aa liked by bonds

Question 20

how does glucose pass through the B-cell in the islets of Langerham?

Answer 20

• weve ate and glucose is in the body and it enters the cell via the GLUT2 transporter mediating facilitated diffusion
• glucose moves down it conc grad and glycolysis and citric acid cycle»ATP increases
• ATP closes the ATP K+ channel so less K+ moving out so more positive inside so cell is depolarised
• depolarisation activates the Ca2+ channels so open and Ca2+ floods into the cell
• this induces Ca2+ induced Ca2+ released.
• causes exocytosis within the secretory granules.

Question 21

how does insulin decrease lower blood glucose?

Answer 21

• increase glucose uptake into cells (skeletal muscle and adipose tissue)
• increase glycogenesis in the liver and skeletal muscle
• decrease glycogenolysis
• decrease gluconeogenesis
• increase glycolysis

Question 22

what does GLUT-4 do?

Answer 22

its a receptor that moves from inside the cell to the membrane when insulin in present in order to allow glucose intake, then GLUT4 moves back into cell when enough glucose has entered cell enocytosis occurs.

Question 23

what is glucagon?

Answer 23

acts to increase blood glucose levels

Question 24

where does glucagon work?

Answer 24

it acts on the cell surface G-protein-coupled-receptor. G protein is GalphaS so increases cAMP

Question 25

where is glucagon secreted from and target cell?

Answer 25

alpha cell, main target cell is the liver