Receptors Flashcards
Can hydrophilic messengers pass through the membrane?
No. They are often too large. They are detected by membrane bound receptors.
Can hydrophobic messengers pass through the membrane?
Yes. Signal receptors can be located inside the cell.
Name three types of membrane receptor
G-protein-coupled-receptors (GPCRs)
Receptor tyrosine kinases (RTKs)
Ion channel receptors
True or False:
G-proteins are receptors on cell surfaces
False.
G-proteins are coupled with receptors called G-protein-coupled-receptors, but the G-proteins themselves are not the receptors
True or False:
G-protein-coupled-receptors (GPCRs) have seven alpha helixes
True
True or False:
G-protein-coupled-receptors (GPCRs) have eight alpha helixes
False
G-protein-coupled-receptors (GPCRs) have seven alpha helixes
G-proteins are inactivated when bound to what molecule?
Guanosine diphosphate (GDP)
G-proteins are activated when bound to what molecule?
Guanosine triphosphate (GTP)
True or False:
Receptor tyrosine kinases (RTKs) are the first enzymes of the pathways they are involved in?
True
They have intrinsic enzyme activity
Fill in the gaps:
Receptor tyrosine kinases (RTKs) add _____ onto _____
Receptor tyrosine kinases (RTKs) add phosphate residues onto other proteins (specifically tyrosine proteins)
True or False:
Receptor tyrosine kinases (RTKs) can only trigger one signal transduction pathway at once
False
Receptor tyrosine kinases (RTKs) can trigger multiple signal pathways at once
True or False:
Abnormal functioning of Receptor tyrosine kinases (RTKs) is associated with many types of cancers.
True
Fill in the gaps:
Before a ligand binds to receptor tyrosine kinases (RTKs), the receptors exist as ______.
Each receptor has a extracellular _____ _____ ____.
Before a ligand binds to receptor tyrosine kinases (RTKs), the receptors exist as (separate) monomers.
Each receptor has an extracellular ligand binding site.
Fill in the gaps:
After a ligand binds to a receptor tyrosine kinases (RTKs), the two monomers associate with each other to from a _____. This is the ____ form.
Ligands binding to the receptors must be _____.
After a ligand binds to a receptor tyrosine kinases (RTKs), the two monomers associate with each other to from a dimer. This is the active form.
Ligands binding to the receptors must be the same.
What is herceptin?
Monoclonal antibody to treat early-stage breast cancer. Binds to RTK receptor HER2, blocks ligands from excessively binding to HER2.