HF

Unit 4: Cell Communication & Cell Cycle

Cell Communication

  • Central Idea: Cell communication is the process by which cells send and receive signals to coordinate their activities.

Main Branches:

Types of Communication

  • Direct Cell Communication: cells communicate with each other through direct physical contact.

    • Gap Junctions: specialized intercellular connections that allow for direct communication and exchange of small molecules between adjacent cells

      • Connexins: Protein channels formed by alignment of two hemichannels from neighboring cells

      • Ion and Small Molecule Exchange

    • Plasmodesmata: microscopic channels along walls of plant cells, connecting the cytoplasm of adjacent cellsq

      • Symplastic Communication

      • Transport of Nutrients and Signals

  • Indirect Cell Communication

    • Autocrine Signaling

      • Cell Signaling to Itself

      • Growth and Proliferation

    • Paracrine Signaling

      • Local Signaling

      • Growth and Development

    • Endocrine Signaling

      • Hormonal Signaling

      • Long-Distance Communication

Signaling Molecules

  • Hormones

  • Neurotransmitters

  • Growth Factors

  • Cytokinesis

Signal Transduction Pathways

  • Receptor Activation

    • Ligand Binding

      • Specificity and Affinity

      • Activation of Receptor

    • Receptor Dimerization

      • Receptor Activation by Dimer Formation

      • Signal Amplification

  • Intracellular Signaling

    • Second Messengers

      • cAMP

      • Calcium Ions

    • Protein Kinases

      • Phosphorylation of Proteins

      • Activation of Cellular Responses

    • Phosphorylation Cascade

      • Amplification of Signal

      • Regulation of Multiple Targets

Cellular Responses

  • Gene Expression

  • Enzyme Activation

  • Cell Growth and Division

  • Apoptosis

Examples

  • Nervous System Communication

    • Synaptic Signaling

    • Action Potentials

  • Immune System Communication

    • Cytokine Signaling

    • Immune Response

Disorders and Diseases

  • Cancer

  • Diabetes

  • Alzheimer's Disease

I. Cell Communication A1. Importance of cell communication 2. Types of cell communication B. Signaling Pathways 1. Reception a. Ligands and receptors b. Membrane receptors c. Intracellular receptors 2. Transduction a. Signal amplification b. Protein kinases and phosphorylation cascades c. Second messengers 3. Response a. Cellular responses b. Gene expression changes C. Cell Signaling Examples 1. Endocrine signaling 2. Paracrine signaling 3. Autocrine signaling 4. Synaptic signaling

II. Cell Cycle A. Overview 1. Importance of cell cycle regulation 2. Phases of the cell cycle B. Interphase 1. G1 phase 2. S phase 3. G2 phase C. Mitosis 1. Prophase 2. Metaphase 3. Anaphase 4. Telophase D. Cytokinesis 1. Animal cell cytokinesis 2. Plant cell cytokinesis E. Cell Cycle Regulation 1. Checkpoints a. G1 checkpoint b. G2 checkpoint c. M checkpoint 2. Cyclins and cyclin-dependent kinases (CDKs) 3. Tumor suppressor genes 4. Oncogenes

III. Cell Communication and Cell Cycle Interactions A. Cell Signaling and Cell Cycle Control 1. Growth factors and cell division 2. Cell cycle checkpoints and signaling pathways B. Cell Cycle Regulation and Cancer 1. Loss of cell cycle control in cancer cells 2. Oncogenes and tumor suppressor genes in cancer development C. Therapeutic Implications 1. Targeting cell signaling pathways for cancer treatment 2. Cell cycle-specific drugs and chemotherapy

Note: This outline provides a concise overview of the topics covered in AP Bio Unit 4, including cell communication and the cell cycle