UNIT 4 CUMU. WARM-UP 2

In cell signaling, how is the flow of specific ions

regulated?

• Opening and closing of ligand-gated channels

• Transduction

• Cytoskeleton rearrangement

• Endocytosis

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.

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

• ligand
• second messenger
• protein kinase
• receptor protein

Which of the following is a chemical message that usually travels through the bloodstream to target cells?

• hormone
• local regulator
• endocrine cell

What determines whether a cell is a target cell for a particular signal molecule?

• phosphorylation cascade
• cAMP
• signal receptors
• phosphatase

Signal amplification is most often achieved by

• an phosphorylation cascade

• binding of multiple signals

• branching pathways

• action of adenylyl cyclase

What do secondary messengers, like cAMP, do?

• transport a signal through the lipid bilayer

• relay & amplify a signal from the outside to the inside of the cell

• relay & amplify a message from the inside of the membrane throughout the cytoplasm

• dampen the message

Which of these is a pro of an enzymatic cascade?

• It leads to regulation

• It amplifies the response of a single binding molecule

• It decreases the response of a single binding molecule

• Because it is unregulated, it provides a variety of responses

The three stages of cell signalling are

• paracrine, local, and synaptic
• reception, transduction, and response
• transcription, translation, and folding
• alpha, beta, and gamma

cAMP and calcium are examples of 

• secondary messengers
• hormones
• ligands
• enzymes