Flashcards in Lecture 11 Deck (12):
converts ATP to cAMP
cyclic AMP (cAMP)
diffuses through the cell and activates a serine/threonine kinase, called protein kinase A,which phosphorylates other proteins
consists of a receptor protein associated with a G-protein on the cytoplasmic side.
? The receptor consists of seven alpha helices spanning the membrane.
? Effective signal molecules include yeast mating factors, epinephrine, other hormones, and neurotransmitters.
Plants and animals use hormones to signal at greater distances
ligand-gated ion channel
are protein pores that open or close in response to a chemical signal.
small molecules that bind specifically to a larger molecule
? Some transmitting cells release local regulators that influence cells in the local vicinity
Most protein kinases act on other substrate proteins, unlike the tyrosine kinases that act on themselves
Rather than relying on diffusion of large relay molecules like proteins, many signal pathways are linked together physically by scaffolding proteins
? Pathways initiated by both G-protein-linked receptors and tyrosine-kinase receptors involve small, nonprotein, water-soluble molecules or ions, called second messengers.
? These molecules rapidly diffuse throughout the cell.
? Two of the most important are cyclic AMP and Ca2+.
The process by which a signal on a cell?s surface is converted into a specific cellular response in several steps called a signal-transduction pathway