Chapter 08 How Cells Communicate with Each Other and with the Environment

These flashcards cover key concepts and definitions from Chapter 08 on cell communication, aiding in exam preparation.

What is cell communication?

The process of cells detecting and responding to signals in the extracellular environment.

What is apoptosis?

The intentional process of cell death caused by signals.

What signaling molecule is responsible for phototropism in plants?

Auxin.

What are the five common ways signals are relayed in cell communication?

1. Direct intercellular signaling 2. Contact-dependent signaling 3. Autocrine signaling 4. Paracrine signaling 5. Endocrine signaling.

What are the three stages of cell signaling?

1. Receptor activation 2. Signal transduction 3. Cellular response.

What is the purpose of a ligand in receptor activation?

It binds noncovalently to a receptor, leading to a conformational change that transmits the signal.

What kind of receptors are most signaling molecules associated with?

Cell surface receptors.

What are enzyme-linked receptors?

Receptors that function as protein kinases, transferring a phosphate from ATP to specific amino acids.

What triggers the activation of G-Protein-Coupled Receptors (GPCR)?

Binding of a ligand to the receptor, which causes it to release GDP and binding of GTP.

What is the role of intracellular receptors?

They bind ligands that diffuse through the membrane, such as steroid hormones.

What is the function of receptor tyrosine kinases?

To stimulate cell growth or division in response to signaling molecules like growth factors.

What is a key feature of the protein kinase cascade in signal transduction?

Signal amplification, as each kinase can activate multiple proteins.

What is a second messenger, and give an example?

Molecules that relay signals inside cells; an example is cyclic AMP (cAMP).

How does epinephrine affect cellular signaling as a first messenger?

It binds to a GPCR and activates a signaling pathway that enhances cellular responses during stress.

What are the advantages of second messengers in signaling pathways?

1. Signal amplification 2. Increased speed of response.