Ep3 What is insulin?
Hi all, so sorry for not posting as frequently as before, over the next few weeks the programme will continue and we will be exploring different variants of diabetes, treatments, CGMs and then delving deep into hormone related diseases including hyperthyroidism, Graves’ disease and many more! 🙂
❓What is Insulin?
Insulin is a hormone secreted by beta cells, which are found in clusters called islets of Langerhans, it helps regulate blood glucose levels by promoting glucose uptake to cells. Insulin is complementary to receptors on the cell membrane (including those in the liver and muscles, not the pancreas itself). When insulin binds to its receptor, it triggers glucose channels to open, allowing glucose to enter cells and be used and stored 9in respiration) – helping to lower blood sugar levels.
💊 Insulin and how it relates to diabetes:
In T1 diabetes, the body cannot produce insulin. People with this condition often need insulin injections. The first successful treatment was in 1922 by the University of Toronto, using insulin extracted from cattle pancreases to save a 14-year old boy who was previously dying from T1 diabetes. He saw saved. Dr. Frederick Banting and Charles Best discovered the hormone. Insulin is also complementary to specific receptors found on the surface of many cells, particularly muscle, liver, and adipose (fat) tissue cells. When insulin binds to its receptor, it triggers a cascade of intracellular signals and one key result is the movement of glucose transporter proteins (like GLUT4) to the cell surface, allowing glucose to enter the cell via facilitated diffusion.
💉 Common injection sites:
- Front of the thighs
- Around the belly button (where there’s more fat for comfortable absorption)
🧪 Molecular structure
- Made of 51 amino acids
- Two chains: A-chain and B-chain, connected by disulphide bridges
- Contains carboxyl group, amine groups, peptide bonds and disulphide bridges (especially between the cysteine residues) – these maintain its tertiary structure.
🏬 Quaternary structure
- Insulin forms dimers in the pancreas and then hexamers for storage
- When released, they break down into monomers, the active form that travels in the bloodstream