Cell Communication (Signaling) Part 2 AP Biology Cell Communication (Signaling) Part 2

Phosphorylation and Hydrolysis

Receptor Protein

G protein Receptor

Tyrosine – Kinase Receptor

Ion Channel Receptors Signal molecule (ligand) Gate closed Ions Plasma membrane Ligand-gated ion channel receptor Gate open Cellular response Gate closed

Intracellular receptors

Secondary Messenger cAMP Adenylyl cyclase Phosphodiesterase Pyrophosphate H2O P P i ATP Cyclic AMP AMP

First messenger (signal molecule such as epinephrine) Adenylyl cyclase G protein G-protein-linked receptor GTP ATP Second messenger cAMP Protein kinase A Cellular responses

Secondary Messenger Calmodulin EXTRACELLULAR FLUID Signal molecule (first messenger) G protein DAG GTP G-protein-linked receptor PIP2 Phospholipase C IP3 (second messenger) IP3-gated calcium channel Cellular re- sponses Various proteins activated Endoplasmic reticulum (ER) Ca2+ Ca2+ (second messenger) CYTOSOL

  Question: All receptor proteins, regardless of name, function or structure, operate the same way to trigger a response within a cell. In no more than three sentences, explain the signal transduction pathway. (5 Points)

Scoring Rubric: 1pt. Discussion of reception and Confirmational shape change. Deduct half point for no mention of conformational shape change. 1pt. Discussion of transduction converting the signal in to a cellular process. 1pt. Discussion of the response occurring. 1pt. Correct use of scientific terms. 1pt. Answer has no more than three sentences. (Following Directions.)   This question addresses Essential Knowledge: 3.D.3