Unit 4: Cell Communication & Cell Cycle

Key Concepts:

• Cell communication and signal transduction pathways

• Types of signaling (autocrine, paracrine, endocrine, synaptic)

• Reception, transduction, and response in signaling cascades

• Role of second messengers (cAMP, Ca²⁺, IP₃)

• Regulation of cellular responses (signal amplification, phosphorylation cascades)

• Feedback mechanisms (positive vs. negative feedback)