Topic 1: Cell Biology

1.1 Introduction to Cells

• Cell Theory: All living things are composed of cells, cells are the basic unit of life, and all cells come from pre-existing cells.

• Exceptions: Striated muscle, giant algae, aseptate fungal hyphae.

• Functions of Life (MR H GREN): Metabolism, Response, Homeostasis, Growth, Reproduction, Excretion, Nutrition.

• Unicellular vs Multicellular: Emergent properties in multicellular organisms.

• Stem Cells: Therapeutic uses (e.g., Stargardt’s disease, leukemia), ethical concerns.

1.2 Ultrastructure of Cells

• Prokaryotes vs Eukaryotes: Differences in structure, binary fission in prokaryotes.

• Organelles in Eukaryotes: Structure & function (mitochondria, nucleus, ribosomes, rough/smooth ER, Golgi, lysosomes, etc.)

• Electron vs Light Microscopes: Resolution differences.

1.3 Membrane Structure

• Phospholipid Bilayer: Hydrophilic heads, hydrophobic tails.

• Membrane Proteins: Integral, peripheral, roles in transport, communication.

• Fluid Mosaic Model: Singer and Nicolson model, vs Davson-Danielli model.

1.4 Membrane Transport

• Diffusion, Osmosis, Facilitated Diffusion, Active Transport

• Endocytosis/Exocytosis: Vesicle transport of large molecules.

1.5 Origin of Cells

• Abiogenesis: Conditions of early Earth, Miller-Urey experiment.

• Endosymbiotic Theory: Origin of mitochondria and chloroplasts.

1.6 Cell Division

• Cell Cycle: Interphase (G1, S, G2), M phase.

• Mitosis: Prophase, Metaphase, Anaphase, Telophase + cytokinesis.

• Cyclins: Control progression through the cell cycle.

• Mitotic Index: Use in cancer diagnostics.