AP Bio-Unit 4-Cell Signaling-Review (Section 5.6)

Which is not a part of a signal transduction pathway?

• response
• transcription
• transduction
• receptor

What role do protein kinases serve?

• remove phosphate groups to deactivate enzymes
• inactivate cAMP to AMP
• add phosphate groups to activate enzyme's
• activate G proteins

Epinephrine (also known as adrenaline or adrenalin) is a hormone and a neurotransmitter. The model for the action of Epinephrine is shown below.
Which of the following molecules act as a second messenger in the cascade by which epinephrine stimulates the activation of the enzyme glycogen phosphorylase?

• Adenosine
• Adenylyl cyclase
• Citric acid
• Cyclic AMP

Signal amplification is most often achieved by

• an enzyme cascade
• binding of multiple signals
• branching pathways
• action of adenylyl cyclase

What is a phosphorylation cascade?

• travelling of hormones through the air
• travelling of hormones through the blood
• the removal of a phosphate
• a series of molecules that get phosphorylated

G proteins are a family of proteins involved in transmitting chemical signals originating from outside a cell into the inside of the cell. G proteins function as molecular switches.
Which of the following best describes the role in which the G protein is most intimately involved in the process shown above?

• Production of the ligand molecule.
• Reception of the signal.
• Transduction of the signal.
• Production of response to signal.

The term steroid describes both hormones produced by the body and artificially produced medications that duplicate the action for the naturally occurring steroids. All of the following describe steroid hormones EXCEPT:

• A.  They bind with receptor proteins in the plasma membrane to trigger cellular responses.
• A.  They are derived from cholesterol and are lipid soluble.
• They serve as ligands in signal transduction pathways
• A.  They are exemplified by testosterone, estrogen and progesterone

Cell signaling involves converting extracellular signals to specific responses inside the target cell. Which of the following best describes how a cell initially responds to a signal?

• The cell experiences a change in receptor conformation
• The cell experiences an influx of ions
• The cell experiences an increase in protein kinase activity
• The cell experiences G protein activation

Which areas in the diagram depict the process of transduction in the signal transduction pathway of cell communication?

• Q and R
• Q and U
• S and T
• T and U

Which of the following can activate a protein by transferring a phosphate group to it?

• cAMP
• G Protein
• protein kinase
• protein phosphatase