The Biology Project > Cell Biology > Cell Signaling > Problem Set

Cell Signaling Problem Set

Problem 8: Protein Kinase Cascades

Some receptors for growth factors activate a protein kinase cascade, with the participation of multiple enzymes to effect a change in gene expression. Which of the following statements about a protein kinase cascade are true?

A.	Multiple steps allow the amplification of the signal.
B.	External signals can lead to changes in gene expression.
C.	Multiple steps leading to kinase activations can result in cells having different responses, depending on the presence or absence of target proteins.
D.	Multiple steps in an activation mean that abnormal stimulation of a cell response such as growth can occur with mutations in more than one gene.
E.	All of the above are true. Yes, protein kinase cascades are important components of membrane signaling. The signal is amplified, target proteins for kinases determine responses, and mutations in signaling pathways are a significant part of cancer cell growth.

The Biology Project > Cell Biology > Cell Signaling > Problem Set