Bio Cellular Signaling Ch 9

Cell signaling pathway

signal reception —> signal transduction —> cellular response

CONCEPT 9.1: _______ signals are converted to _______ within the cell

CONCEPT 9.1: External signals are converted to responses within the cell

• Ancestral signaling molecules likely evolved in prokaryotes and single-celled eukaryotes and were adopted for use in their multicellular descendants

CONCEPT 9.2: ________: A ______ing molecule binds to a _______ ________, causing it to change ______

CONCEPT 9.2: Reception: A signaling molecule binds to a receptor protein, causing it to change shape

• The binding between a signal molecule (ligand) and receptor is highly specific

• A shape change in a receptor is generally the initial transduction of the signal

• Most signal receptors are plasma membrane proteins, but others are located inside the cell

CONCEPT 9.3: ______: _______ of _______ interactions transmit ______ from ______ to _____ molecules in the cell

CONCEPT 9.3: Transduction: Cascades of molecular interactions transmit signals from receptors to relay molecules in the cell

• Cell signaling is usually a multistep process

• Multistep pathways can greatly amplify a signal

• Multistep pathways provide more opportunities for coordination and regulation of the cellular response

CONCEPT 9.4: _______ __________: Cell ______ leads to _________ of ___________ or _________ activities

• The cell’s response to an extracellular signal is called the “______________”

CONCEPT 9.4: Cellular response: Cell signaling leads to regulation of transcription or cytoplasmic activities

• The cell’s response to an extracellular signal is called the “output response”

Signal receptors, relay molecules, and second messengers participate in a variety of pathways, leading to nuclear and cytoplasmic responses, including cell division