Unit 4a - Cell Communication Flashcards
(29 cards)
Autocrine Signaling
Cell signals itself
Juxtacrine Signaling
Two cells are in contact w/ one another
Paracrine Signaling
Two cells that are close but not touching
Endocrine Signaling
When ligands travel long distances to signal
What are the 3 steps of cellular signaling
Reception
Transduction
Response
Reception
Detection of a ligand coming from outside the cell
Transduction
Converting a signal to a form that can bring about a response
Response
Cellular response to the signal molecule
Ligand
Signaling molecule that binds w/ a receptor.
What are the two types of receptors
Plasma Membrane
Intracellular
What happens in the FIRST step of a G-protein Receptor reaction?
The G protein has an inactive GDP.
What happens in the SECOND step of a G-protein Receptor reaction?
The ligand bonds to the receptor and the protein bonds to the receptors. The protein exchanges a GDP for a GTP.
What happens in the THIRD and FOURTH steps of a G-protein Receptor reaction?
The ligand unbinds w/ the receptor ; the protein (w/ GTP) binds with an enzyme and a cellular response occurs ; the GTP is turned to a GDP.
What happens in the FIRST step of a Tyrosine Kinase Receptor reaction?
A ligand is introduced near the inactive receptor.
What happens in the SECOND step of a Tyrosine Kinase Receptor reaction?
Ligands bind w/ the tyrosine kinase –> A dimer is created when the two kinase bind together.
What happens in the THIRD step of a Tyrosine Kinase Receptor reaction?
Six ATP give up one phosphate to the 6 tyrosine molecules on the kinase , becoming ADP.
What happens in the FOURTH step of a Tyrosine Kinase Receptor reaction?
Multiple cellular responses occur.
What happens in the FIRST step of Ligand Gated Ion Channel?
The receptor is closed w/o an ligand to bind and open it.
What happens in the SECOND and THIRD steps of a Ligand Gated Ion Channel?
The ligand binds to the receptor and the gate opens –> a cellular response occurs –> ligand detaches and the gate closes.
What is the structure of the G-Protein Coupled Receptor?
7 transmembrane segments.
Cascades
Relay signals from receptor to target molecule.
What is the structure of the Ligand Gated Ion Channel Receptor?
Signal on receptor changes shape ( to regulate the flow of specific ions)
Protein Kinase
Enzyme that phosphorylates and activates proteins at the next level.
Phosphorylation Cascade
Enhance and amplify signals
