Test review unit 4 topics 1-4

Plasmodesmata

communication through cell junctions signaling substances and other materials dissolved in the cytoplasm can pass freely between adjacent cells

Local regulations: in paracrine signaling secretory cells release local regulators via Exocytosis to an adjacent cell

In animal nervous systems, neurons secrete neurotransmitters, diffusing across the synaptic cleft (space between the nerve cell and target cell)

An example of long distance

Hormones

release hormones that travel in the plant vascular tissue (xylem and phloem) or through the air to reach target tissues

Endocrine signaling; specialized cells release for one’s into the circulatory system where they reach target cells

Binds to ligands that are polar, large, water soluble ex, G protein coupled receptors (GPCRs), ligand-gated ion channels

Binds to ligands that can pass through the plasma membrane, hydrophobic ex, steroid and thyroid hormones, gases

Second messengers

Small, non proteins, molecules and ions help relay the message and amplify the response ex, Cyclic AMP

Neurons communicate with one another by sending Nuerotransmitters

It binds to a G protein that can bind to GTP, LIGAND BINDING TO GPCR ON THE EXTRACELLULAR SIDE HAS TO HAPPEN

Causes cytoplasmic side to change shape and allows for the G protein to bind to GPCR and thus activates them

Receptors that act as a gate for ions

Dephosphorylation by the enzyme protein phosphatate will shut off pathways.

BOTH USE HORMONES

Plants release hormones in plants vascular tissue or air to travel to target cell

Animals use endocrine signaling (circulatory system)