Cell Signaling Pathways

Front

How do growth factor receptor kinases work?

Back

Inactive (in this case) tyrosine-kinase receptor monomers are bound by an extracellular growth factor, which activates and DIMERIZES the receptors. The tyrosine on the receptor is activated by phosphorylation and is bound by intracellular signaling proteins (INSULIN works this way)

Front

What is Ras?

Back

A small GTP binding protein that is one of the most commonly mutated proteins in cancer

Front

What does Ras do in growth factor signaling?

Back

Inactive Ras is bound to a GDP, and once GDP is replaced by GTP, the Ras protein is activated. It can now bind to the intracellular proteins that have bound to the phosphorylated tyrosine-kinase receptors and regulate the growth factor signaling, it can also regulate MAP kinases

Front

What are MAP kinases?

Back

Mitogen Activated Protein (MAP) kinases are involved in cell proliferation, regulated by Ras

Front

T or F: the epidermal growth factor (EGF) receptor is highly mutative in cancer

Back

T

Front

What is arrestin?

Back

Protein that interacts with the alpha-subunit on a G-protein and prevents any further signaling from occurring

Front

How can cells terminate a signal transduction between its cell surface receptors?

Back

Internalizing and degrading the receptor-agonist complex, modifying a receptor so it inactivates, or by reducing the receptor or agonist availability through receptor internalization

Front

What are 3 examples within the body that use cell pathway signaling to perform a function?

Back

Striated muscle contraction using intracellular Ca2+, zymogen secretion from pancreatic acini, and insulin secretion from the pancreas

Front

Why is Xylitol dangerous for dogs?

Back

The pancreas confuses xylitol with glucose and releases insulin, removing glucose from the blood, causing blood sugar levels to drop (hypoglycemia) and possibly liver damage.