Features Of Signal Pathways

Question 1

Ligand gated ion channels

Answer 1

• very fast response time, a few msecs
• very short acting, a few to a hundred msecs
• common on nerves and muscles
• signal amplification is through membrane potential

Question 2

GPCR

Answer 2

• fast response times, hundreds of msecs
• short acting, secs to mins
• common for both neurotransmitters and hormones
• uses small molecule second messengers
• modifies protein function (fast) and gene transcription (slower)

Question 3

Catalytic receptors

Answer 3

• fast to slow response times, seconds to hours
• moderate to long acting, mins to hours
• common for growth factors and hormones
• modify protein function by phosphorylation
• modifies gene expression

Question 4

Steroid receptors

Answer 4

• very slow response times, hours
• long acting, hours to days
• actions through gene trascription