Cell Communication Quiz

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

• signal cell

• phospholipid bilayer

• signal receptors

• mitochondria

Which substances are found on cell surfaces and respond to nerve and hormone signals?

• starches and simple sugars

• subunits of DNA

• vitamins and minerals

• receptor molecules

Ligand binding sites

• must be the right shape to have the ligand attach to it

• are often found freely floating in the bloodstream

• are typically made from phospholipids

• A and C

True or False. After the ligand binds, the intracellular domain of a receptor protein changes shape, initiating transduction of the signal.

• True

• False

1.  Each of the following numbered processes are involved in signal transduction pathways:  
 I.  Response  
II.  Amplification  
 III.  Reception  
IV.  Transduction
Which of the following 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 is a G protein?

• specific type of membrane-receptor protein
• protein on the cytoplasmic side of a membrane
• membrane-bound enzyme
• relay protein

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

Do plant cells communicate using hormones?

• yes
• no

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