When levels go above or below a set point a hormone is released to return the body to set point. When the body is restored to set point no more hormone is released. This is an example of...

• a positive feedback loop
• a negative feedback loop
• a neutral feedback loop

Tags

NGSS.HS-LS1-3

The 3 steps of signal transduction in order are

• reception, transduction, response
• response, transduction, reception
• reception, response, transduction
• transduction, reception, response

Protein kinases activate other relay proteins by adding a(n) ____ to them.

• phosphate
• ATP molecule
• cAMP
• GTP

Which of the following is an example of a second messenger?

• cAMP
• GTP
• insulin
• epinephrine

Signal amplification is most often achieved by

• an enzyme phosphorylation cascade

• binding of multiple signals

• branching pathways

• action of adenylyl cyclase

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

When epinephrine binds to cardiac (heart) muscle cells, it speeds their contraction. When it binds to muscle cells of the small intestine, it inhibits their contraction. Which of the following best accounts for the fact that the same hormone can have different effects on muscle cells?

• Cardiac cells have more receptors for epinephrine than do intestinal cells
• Epinephrine circulates to the heart first and thus is in higher concentration around cardiac cells
• The two types of muscle cells have different signal transduction pathways for epinephrine and thus have different cellular responses
• Cardiac muscle is stronger than intestinal muscle and thus has a stronger response to epinephrine

Each of the following numbered processes are involved in signal transduction pathways:  
 I.  Response  
II.  Amplification  
 III.  Reception  
IV.  Transduction
Which represents the sequence of events in a typical signal transduction pathway?

• I, II, III, IV
• III, I, IV, II
• II, IV, I, III
• III, IV, II, I

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

• ligand
• second messenger
• protein kinase
• receptor protein

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

• phosphorylation cascade
• cAMP
• signal receptors
• phosphatase