Cell Signaling AP Biology

In cell signaling, how is the flow of specific ions

regulated?

• Opening and closing of ligand-gated channels

• Transduction

• Cytoskeleton rearrangement

• Endocytosis

What is a G protein?

• A protein on the cytoplasmic side of the a membrane that becomes activated by a receptor protein

• A specific type of membrane receptor protein

• A membrane bound enzyme that converts ATP to cAMP

• A tyrosine kinase relay protein

Many signal transduction pathways use second messengers to:

• transport a signal through the lipid bilayer portion of the plasma membrane.

• relay a signal from the outside to the inside of the cell.

• relay the message from the inside of the membrane throughout the cytoplasm.

• amplify the message by phosphorylating proteins.

What could happen to the target cells in an animal that lack receptors for local regulators?

• They could compensate by receiving nutrients via an α factor.

• They could develop normally in response to neurotransmitters instead.

• They could divide but never reach full size.

• They would not be able to multiply in response to growth factors from nearby cells.

A signal molecule that binds to a plasma-membrane protein is a

• ligand
• second messenger
• protein kinase
• receptor protein

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

• cAMP
• G Protein
• protein kinase
• protein phosphatase

What do second messengers do?

• transport a signal through the lipid bilayer
• relay a signal from the outside to the inside of the cell
• relay message from the inside of the mebrane throughout the cytoplasm
• dampen the message

Signal amplification is most often achieved by

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

What does a protein phosphatase do?

• removes phosphates
• transfers phosphates from ATP to proteins
• activates an enzyme with a signal molecule

What does a protein kinase do?

• removes phosphates
• transfers phosphates from ATP to proteins
• activates an enzyme