Unit 4 Quiz Review (AP)

What is the initial molecule that binds to a receptor in cell communication known as?

• Activator

• Enhancer

• Ligand

• Repressor

What is the first step of signal transduction?

• Termination

• Response

• Reception

• Transduction

All cells respond to the same ligand with the same response.

• True

• False

What is the function of second messengers, such as Ca²⁺ and cAMP, in a cell signaling pathway?

• To help the ligand bind to the receptor

• To amplify the signal inside the cell

• To terminate the signal transduction pathway

• To act as a receptor on the cell membrane

Which of the following structures turns gene expression on or off?

• DNA polymerase

• Transcription factor

• Promoter

• RNA polymerase

What is the main purpose of a signal transduction pathway?

• To break down molecules

• To communicate with other cells

• To convert a signal into a specific cellular response

• To synthesize proteins

What type of signaling involves the release of signals into the bloodstream to reach distant cells?

• Paracrine signaling

• Endocrine signaling

• Autocrine signaling

• Juxtacrine signaling

What happens immediately after a ligand binds to a receptor on the cell surface?

• The receptor is degraded

• The receptor undergoes a conformational change

• The ligand is destroyed

• The cell undergoes division

What is the function of protein kinases in signal transduction pathways?

• To deactivate enzymes

• To phosphorylate other proteins

• To synthesize DNA

• To transport ions

Which signaling pathway involves local communication through which neurotransmitters diffuse across the space between the nerve cell and a target cell?

• Endocrine

• Paracrine

• Synaptic

• Autocrine