Cell Structure & Function Lecture 10 Flashcards
What are the four steps of intercellular signalling?
Signal reception, signal processing and tranduction, signal response, signal deactivation
What happens at signal reception?
Small molecules bind to receptors
Receptors send signal into cytosol
Signal is amplified
Signal is responded to in the nucleus
What happens when the signal is received at the receptor?
The receptors makes a conformational change and create a new complex specific to the signal it receives if it fits
What happens for steroid hormone signal reception?
The steroid diffuses through the lipid bilayer
Attaches to a receptor in the cytosol
Receptor travels into nucleus and changes the gene expression of the DNA`
What is the signalling molecule called for a gated ion channel?
Ligand
What happens with a ligand gated ion channel?
Molecule binds and opens the gate which lets the ions flow through inducing a cellular response
If a primary messenger is hydrophobic then it is?
Lipid soluble (steroid)
What happens if hormones cannot diffuse through the plasma membrane?
They rely on signal transduction pathways to convert extracellular signal to an intracellular signal (involves G proteins or receptor protein kinases)
What does signal responses do?
Changes gene expression
Activates specific proteins
Metabolism
How to cells turn off signals?
Cells have automatic & rapid mechanisms for signal deactivation
This protects them for future activation from more hormone signals
