Unit 4: Cell Communication

Which of the following terms represents a signaling molecule?

• Receptor

• Ligand

• Cofactor

• Enzyme

Which of the following terms represents a molecule that receives a signaling molecule?

• Receptor

• Ligand

• Cofactor

• Enzyme

What type of cell communication occurs when a cell releases ligands that are received by nearby neighboring cells that have a receptor for the ligand?

• Autocrine

• Endocrine

• Juxtacrine

• Paracrine

What type of cell communication occurs when a cell releases a ligand that is used to regulate itself?

• Autocrine

• Endocrine

• Juxtacrine

• Paracrine

What type of cell communication occurs when the neighbors in direct contact with a signaling cell receive its ligands?

• Autocrine

• Endocrine

• Juxtacrine

• Paracrine

What type of cell communication occurs when the signaling cell secretes ligands that travel longer distances to its target cells, for example through the bloodstream?

• Autocrine

• Endocrine

• Juxtacrine

• Paracrine

True or false: Ligands can be proteins or lipids

• True

• False

True or false: Ligands can only be proteins or lipids

• True

• False

True or false: Small nonpolar lipid ligands can travel directly through the cell membrane to reach internal receptors.

• True

• False

True or false: A transmembrane receptor protein is required for all ligands.

• True

• False