AP BIO UNIT 4

What are the three parts of signal transduction pathway?

• reception, transduction, response

• confirmation, transduction, transcription

• reception, amplification, transcription

• confirmation, amplification, response

Transduction step traditionally amplifies the signal, which of the following is not directly involved with transduction?

• secondary messengers

• protein modification

• phosphorylation cascade

• ligands

Describe what occurs when a ligand binds to a receptor.

• confirmational change in shape of receptor

• phosphorylation of ligand

• ligand passes through the membrane

• receptor binds additional ligands

An example of LOCAL cell communication is:

• White blood cells bumping into each other sharing antigen info

• Neurons communicating across a synapse

• Hormones traveling through the blood stream to target tissues

An example of DIRECT cell communication is:

• White blood cells bumping into each other sharing antigen info

• Neurons communicating across a synapse

• Hormones traveling through the blood stream to target tissues

What determines whether a signal molecule binds on the surface or enters the cell?

• size
• polarity
• ability to cross the membrane
• all of these are correct

The binding of a ligand to a ligand-gated ion channel can cause the channel to ___.

• open

• close

• both answers can be correct

A cell converting a chemical signal into a cellular response is known as __.

• energetics

• transduction

• ligand response

• transformation

Signal amplification is most often achieved by

• a signaling 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