Chapter 18 Flashcards
Cells express receptors in order to?
respond to signals in their environment
The cell receptors receive the signal and convey the information to intracellular targets via
signal transduction
5 categories of signaling
a. neurotransmitter (synaptic)
b. endocrine
c. paracrine
d. autocrine
e. contact-dependent
What are 8 general classes of proteins/mechanisms involved in signal transduction?
a. G protein-coupled receptors
b. receptor protein kinase
c. phosphoprotein phosphatases
d. guanylyl cyclase
e. ion channel receptors
f. two-component system
g. transmembrane scaffolds
e. nuclear receptors/transcription factors
G protein-coupled receptors are linked to
trimeric GTP-binding proteins
Function of receptor protein kinases
phosphorylate their intracellular substrates
Function of phosphoprotein phosphatases
dephosphorylate substates
Function of guanylyl cyclase
catalyzes the GTP to 3’-5’ cyclic GMP
Function of ion channel receptors
change their conformation to permit ion flux through a pore
What are the 2-component system?
a sensor + a response regulator
Function of transmembrane scaffolds
help recruit regulatory proteins to a site on the membrane
Most cell-sensed signals are _____
chemical
What are 4 receptors that can respond directly to physical inputs?
a. pressure-sensing channels
b. mechanical strain sensors
c. electrical field sensing channels
d. heat/pain sensing o ion channels
