Cell Signaling and Apoptosis

Flashcards covering the key concepts of cell signaling and apoptosis based on lecture notes.

What are signal transduction pathways?

Processes crucial for many cellular functions, allowing communication between cells.

How do bacterial cells sense their environment?

Through a process called quorum sensing, allowing them to detect the local density of their population.

What is the first step in a three-stage cell-signaling pathway?

Reception, where a signaling molecule binds to a receptor.

What major types of cell-surface receptors are there?

G protein-coupled receptors (GPCRs), receptor tyrosine kinases (RTKs), and ligand-gated ion channels.

What happens when a signaling molecule binds to a GPCR?

It activates a specific G protein, which then propagates the signal.

What do receptor tyrosine kinases do upon ligand binding?

They form dimers and add phosphate groups to tyrosines on the other monomer.

What role do second messengers play in signal transduction?

They help relay signals quickly within the cell, for example, cyclic AMP and Ca2+.

How do protein kinases and second messengers differ?

Protein kinases add phosphate groups to proteins, while second messengers help propagate signals within the cytosol.

What is apoptosis?

Programmed cell death that occurs in an orderly fashion, disposing of cell components.

What key process does apoptosis rely on?

Activation of caspases and nucleases, which are enzymes involved in the apoptotic process.

What is one of the ways apoptosis can be triggered?

Through signals originating from either outside or inside the cell.