Back to AI Flashcard MakerBiology /OCR Biology A - 5.1.4 - Hormonal Communication Part 2

OCR Biology A - 5.1.4 - Hormonal Communication Part 2

Biology20 CardsCreated about 1 month ago

This deck covers key concepts related to hormonal communication, focusing on insulin and glucagon functions, blood glucose regulation, and diabetes.

What does insulin act on

Hepatocytes; Muscle cells; Adipose tissue; Brain cells
Tap or swipe ↕ to flip
Swipe ←→Navigate
1/20

Key Terms

Term
Definition
What does insulin act on
Hepatocytes; Muscle cells; Adipose tissue; Brain cells
When is insulin secreted
When blood glucose conc is too high
How does insulin work
Binds to receptors which activate a second messenger system
What does insulin do
Increase glucose uptake into cells by facilitated diffusion; Increase respiration rate (glycolysis); Glycogen conversion (glycogenesis) in hepatocytes...
What does glucagon work on
`Hepatocytes and muscle cells | Has spp receptors
When is glucagon secreted
When blood glucose is too low

Related Flashcard Decks

Study Tips

  • Press F to enter focus mode for distraction-free studying
  • Review cards regularly to improve retention
  • Try to recall the answer before flipping the card
  • Share this deck with friends to study together
TermDefinition
What does insulin act on
Hepatocytes; Muscle cells; Adipose tissue; Brain cells
When is insulin secreted
When blood glucose conc is too high
How does insulin work
Binds to receptors which activate a second messenger system
What does insulin do
Increase glucose uptake into cells by facilitated diffusion; Increase respiration rate (glycolysis); Glycogen conversion (glycogenesis) in hepatocytes and muscle cells; Lipogenesis
What does glucagon work on
`Hepatocytes and muscle cells | Has spp receptors
When is glucagon secreted
When blood glucose is too low
What does glucagon do
Glycogen breakdown (glycogenolysis); Decrease glucose uptake; Converting fatty acids and amino acids to glucose (gluconeogenesis)
Normal glucose conc
4-6 mmol dm3
When blood glucose conc rises
Detected by beta cells in islets of Langerhans; Secretes more insulin; Hepatocytes and muscle cells remove glucose from blood and convert to glycogen (glycogenesis); Blood glucose falls; -ve feedback
When blood glucose conc falls
Detected by alpha cells in islets of Langerhans; Pancreas secretes more glucagon; Hepatocytes and muscle cells convert glycogen to glucose and release it in to bloodstream (glycogenolysis); Blood glucose conc rises; -ve feedback
Describe how insulin secretion is controlled
VG K+ channels in plasma membrane open and K+ diffuses out of beta cell and inside has pd of -70; Blood glucose conc. increases and glucose enters cell; Glucose is phosphorylated then metabolised to form ATP; Presence of extra ATP causes ligand-gated K+ channels to close; K+ cannot diffuse out so membrane potential reduces to only -30; VG Ca2+ open to response in change in membrane potential - Ca move in; Ions cause vesicles to release insulin (exocytosis) into bloodstream
Processes that lower blood glucose
Glycolysis; Glycogenesis; Lipogenesis
Processes that increase blood glucose conc
Gluconeogenesis | Glycogenolysis
Causes of type 2 diabetes
Obesity; Poor diet; Insufficient exercise; Diet high in sugar; Genetics
Insulin resistance
Symptom of Type 2 diabetes | When the body doesn't respond to insulin
Hyperglycaemia
High blood glucose
What can long-term hyperglycaemia lead to
Modification of diff proteins e.g. collagen in blood vessels --> angina and heart failure; Also affects peripheral nerves (poor blood circulation)
Causes of Type 1 diabetes
Majorly genetically linked but environmental factors such as an infection which causes the immune system to destroy beta cells w/ similar antigens
Hypoglycaemia
Excessive, abnormal thirst; Frequent urination; Tiredness; Glucose is excreted in urine instead of being used in body
Why are Type 1 diabetics frequently dehydrated
Glucose increases osmolarity so more water is lost in urine