Final - Chapter 9.1-9.3, Chapter 10.1-10.2 Flashcards
Conformational changes in a receptor
lead to a response within the cell
Signals allow cells to
respond to a changing environment and communicate
What are the five types of signals between cells?
1) direct intercellular signaling, 2) contact-dependent signaling, 3) autocrine signaling, 4) paracrine signaling, and 5) endocrine signaling
With direct intercellular signaling,
cell junctions allow signaling molecules to pass from one cell to another
In contact-dependent signaling,
molecules bound to the surface of cells serve as signals to cells coming into contact with them
In autocrine signaling,
cells secrete signaling molecules that bind to their own cell surface or similar neighboring cell
In paracrine signaling,
the signal doesn’t affect the originating cell, it influences nearby cells
In endocrine signaling,
hormones travel long distances and have longer lasting effects
What are the three stages of cell signaling?
1) receptor activation, 2) signal transduction, and 3) cellular response
During cell signaling, what occurs during receptor activation?
A signaling molecule binds to the receptor
During cell signaling, what occurs during signal transduction?
The activated receptor stimulates a sequence of changes - signal transduction pathway
During cell signaling, what are three types of possible cellular responses?
A change in enzymatic activity, a change in the function of structural proteins, or a change in gene expression
A ligand is
a signaling molecule
Ligands bind with
high specificity
What are the three types of cell surface receptors?
1) enzyme-linked receptors, 2) G-protein-coupled reactions, and 3) ligand-gating ion channels
What happens to the domains of enzyme-linked receptors?
The extracellular domain binds the signal while the intercellular domain becomes a functional catalyst
How are G-protein-coupled reactions/receptors activated?
A G protein binds to a receptor
G protein releases
GDP and binds GTP instead
GTP binding causes what to a happen to a G protein?
The G protein dissociates into an a subunit and a B/y dimer, which affects signaling pathways
What happens when a ligand binds in a ligand-gating ion channel?
It causes ion channels to open so ions can flow through the membrane
Ligand-gating ion channels can transmit synaptic signals between ___ and muscles or between two ___
neurons, neurons
With G-protein-coupled reactions, ___ relay signals within cells
second messengers
GPCR
G-protein-coupled receptors
Signal binding to GPCR actiavtes
the G protein to bind to GTP, causing dissociation and frees a a subunit
