receptors and agonist Flashcards
What role do receptors play in the body?
Receptors are protein molecules that transmit messages into cells, facilitating communication pathways within the body.
What occurs when a neurotransmitter binds to a receptor?
Binding induces a change in the shape of the binding site and protein, transmitting a signal.
What are the three main types of membrane-bound receptors?
Ion channel receptors, kinase-linked receptors, and G-protein-coupled receptors.
How do agonists function?
Agonists mimic natural neurotransmitters and activate receptors by binding with the correct binding groups in the right position and being the correct size for the binding site.
What is critical for an agonist’s effectiveness?
The presence and correct positioning of binding groups, as well as the correct size and shape to fit the binding site.
How do antagonists interact with receptors?
Antagonists bind to the receptor without activating it, inhibiting the binding of natural messengers and deactivating the receptor.
What is the “umbrella” effect in allosteric modulation?
It is when antagonists bind near the active site and act as an “umbrella,” preventing the natural substrate from accessing the active site.
What defines a partial agonist?
Partial agonists bind to receptors and induce suboptimal conformational changes, leading to reduced effects compared to full agonists.
How do inverse agonists differ from antagonists?
Inverse agonists reduce or prevent the inherent activity of receptors that are active even without a chemical messenger, unlike antagonists which block receptor activation.
Why do partial agonists show both agonist and antagonist activity?
They may utilize different binding regions within the active site, resulting in varying effects.
What is the equilibrium concept in receptor activity?
Receptors may exist in an equilibrium between active and inactive forms, influenced by agonists and antagonists.
