Unit 4: Cell Communication and Cell Cycle

In Unit 4, students continue to learn about the role of cells, focusing on how cells use energy and information transmission to communicate and replicate. Through systems of complex transduction pathways, cells can communicate with one another. Cells can also generate and receive signals, coordinate mechanisms for growth, and respond to environmental cues. To maintain homeostasis, cells respond to their environment. They can also replicate and regulate replication as part of the cell cycle that provides for the continuity of life. In Unit 5, students will move on to learn about heredity. ^{(AP® Biology CED)}

4.1: Cell Communication

Topics: Signal transduction pathway (its 3 steps), target cells, ligands, autocrine signaling, paracrine signaling, endocrine signaling

4.2: Introduction to Signal Transduction

Topics: Reception -> Transduction -> Response, cell surface receptors (ligand-gated ion channels, g-protein coupled receptor, receptor tyrokinases), phosphorylation cascade, second messengers

4.3: Signal Transduction

Topics: The effects of signaling on a cell's actions, apoptosis, epinephrine signal transduction pathway

4.4: Changes in Signal Transduction Pathways

Topics: Mutations, environmental conditions affecting the signal transduction pathway, inhibitors and activators

4.5: Feedback

Topics: Positive and negative feedback, homeostasis, insulin pathway

4.6: Cell Cycle

Topics: Parts of the cell cycle (interphase, mitosis, G1, S, G2, PMAT), cells that don't go through the cell cycle

4.7: Regulation of Cell Cycle

Topics: Cyclin-Dependent Kinases (CDKs), checkpoint regulation, cancerous cells