Question

A tyrosine kinase receptor is different from a G-protein linked receptor in that it can trigger _________ at the same time. When both __________ are in their receptor sites, the molecules form a dimer – two molecules joined together. ATP is converted to ADP and the ___________ gets attached to the tyrosine molecules. The addition of the ____________ causes a cascade of cellular responses.

Answer 1

Answer:

1. multiple pathways
2. ligands/signaling molecules
3. inorganic phosphate
4. inactive relay proteins

Explanation:

Receptor Tyrosine Kinase:

• Receptor tyrosine kinase (RTK) is the largest class of enzyme linked cell surface receptors.
• When a growth factor or a ligand binds to two neighboring RTK receptors, the two receptors bind together and form a dimer.
• This change in the conformation of the RTKs activates the associated tyrosine kinase enzymes.
• Tyrosine kinases break down ATP to ADP and phosphorylate the RTKs. Cross phosphorylation between the receptors helps activate multiple tyrosine kinases on the neighboring RTK.
• Once phosphorylated, the cytoplasmic ends of the RTKs are available for docking by relay proteins or signaling molecules with an SH-2 domain.