Chapter 9

Examples of paracrine signaling

- Signals between immune cells - signals that coordinate the activities of cluster of cells during delelopment

The three subclasses of membrane receptors

-Enzymatic receptors -channel - linked receptors - G protein- coupled receptors

Types of cell communication

-Paracrine signaling - Synaptic signaling -endocrine signaling - Direct contact

Some cells send signals to themselves by secreting molecules that bind to receptors in their own plama membranes.

Autocrine signaling

Which signaling process occurs when cells release signals that travel long distances to affect target cells?

Endocrine signaling

How are G protein- coupled receptors different from enzymatic receptors

G protein coupled receptors act indirectly withthe help of an assisting protein

Hoe are G protein coupled receptors different from enzymatic receptors?

G protein- coupled receptors act indirectly with the help of an assisting protein

Identify the intracellular proteins that binds guanosine triphosphate (GTP) and guanosine disphate (GDP)

G proteins

compare endocrine, paracrine and autocrine signaling

Hormones are longer lived than paracrine or autocrine signals

What term is used to describe a signaling molecule

Ligand

In what type of signaling do secretions from one cell have an effect only on the celss in the neighboring area

Paracrine

The class of enzymes that removes phosphate groups, thus reversing the action of kinases

Phosphatases

What effects do paracrine signals have?

Short - lived, local effects

Autophosphorylation occurs when

Two receptor- ligand complexes associate and phosphorylate each other.

In animals, recepter kinases are usually ________ kinases; in contrast, plant receptors kinases belong to the ______ - theonine type.

Tyrosine, serine

The process of ______________ occurs when two receptor- ligand complexes associate together and phosphorylate each other

autophosphorylation

The process of cell communication

cell communication includes interaction between signal and receptor, signal transduction, and a cellular response

The proteins that allow the diffusion of ions across cellular membranes

channel- linked receptors

The association of a neuron and its target cell is called a _____________ synapse.

chemical

Intracellular receptors are usually located in the _________ or in the _______________.

cytoplasm, nucleus

Prior to binding the hormone, steroid hormone receptors are located in the ____________, however, their promary site of action is the ___________

cytoplasm, nucleus

In _________ contact, the signal is a molecule located in the plasma membrane of one cell, while the receptor protein is located in the plasma membrane of another, adjacent cell.

direct

Hormones, which are involved in _____________ signaling, last longer than signaling molecules involved in autocrine and paracrine signaling.

endocrine

Intracellular receptors bind this type of ligand

hydrophobic

Small molecules or ions that relay signals inside the cytoplasm are called second

messengers

A protein activated by a kinase can be deactivated by a different type of enzyme called a _____________

phosphatase

Two common ____________ messengers are cAMP and calcium ions

second

Different cells can respond to the same signaling molecule in a completly different way because they have different ________ ___________ pathways associated with that signaling molecule.

signal transduction

What happens when a signaling molecule binds to a channel- linked receptor.

the channel opens and allows the flow of ions through the membrane

What happens when a signaling molecule binds an enzymatic membrane receptor

the receptor is activated

A signal _______________ pathway is initiated when a ligand binds to a receptor protein.

transduction