Topic 1: Cell-to-Cell Signaling

Cell-to-cell signaling is critical for…?

The function & survival of cells

What is cell-to-cell signaling responsible for?

The growth and development of multicellular organisms

C-to-C signaling involves of the transmission of…?

A signal from a sending cell to a receiving cell

What ways do cells communicate?

1. Direct Contact

2. Local or long-distance signaling

What is direct contact?

Communication by cell-cell contact

What does direct contact do?

Allows signaling substances to exchange directly between the cytoplasm of two adjacent cells via channels

Annimal Cells:

Gap Junction

Plant Cells:

Plasmodesmata

What can complementary cell-surface molecules between adjacent cells do?

Interact & bind to each other

Paracrine signaling is a form of?…

Local Signaling

What is happens during paracrine signaling?

A signaling cell that will release

What is paracrine signaling?

When chemical messages (ligands) travel a short distance through extracellular fluid, causing a response in nearby target cells

Where does synaptic signaling occur?

In animal nervous systems

What happens during synaptic signaling?

Neurons secrete neurotransmitters that diffuse across the synaptic cleft and bind to receptors, causing a chemical change inside the receiving cell

What is autocrine signaling?

When a cell signals to itself

What happens during autocrine signaling?

1. Cells release a ligand that binds to receptors on the same cell to initiate signaling

2. Allows the cell to regulate itself through positive and/or negative feedback

What molecules do animals and plants use for long-distance signaling?

Hormones

Why do animal and plants use hormones?

To produce a response in target cells that may be far from the signaling cell

Plants release hormones that travel in what?

Plant vascular tissue (xylem & phloem) or through the air to reach target tissues

What signaling do animals use?

Endocrine Signaling

What does endocrine signaling do?

Release hormones from specialized cells into the circulatory system where they reach target cells

Cell signaling begins with an interaction between what?

A ligand & receptor

What are ligands?

Chemical Messengers