Phosphorylation cascades involving a series of protein kinases are useful for cellular signal transduction because:

One target of S-Cyclin-Cdk is:

Irradiated mammalian cells usually stop dividing and arrest at a G1 Checkpoint.  Place the following events in the order in which they would occur. 1. production of p21 2. DNA damage 3. inhibition of cyclin-Cdk complexes 4. accumulation and activation of p53

Eukaryotic cells are able to trigger the release of molecules from secretory vesicles to the extracellular space using a process called exocytosis.  An example of molecules commonly released this way is:

Which of the following proteins would lack a sorting signal (signal sequence)?

In which organelle does photophosphorylation occur?

Ligand gated ion channels

Sutherland discovered that epinephrine:

A female patient diagnosed with osteoporosis tells the nurse that she is going to try to exercise regularly. Which exercise should the nurse recommend?

Which of these mechanism ensures that DNA replication is accurate?