All courses · core course
Cell Biology
A core course for biology majors and premedical students. It starts with how cells are measured and how experiments tell mechanisms apart, then follows membranes and compartments, the traffic of proteins and vesicles, the cytoskeleton and motors, the cell cycle, division and cell death, and ends with cells in tissues: adhesion, epithelia, stem cells and cell state.
5 units · 26 lessons
Unit 1 · Seeing and testing cells
- Unit 1: Seeing and testing cells A Measured Eukaryotic Cell A hamster cell in culture is about one quarter nucleus. A fission yeast cell is under one tenth. Why the difference?
- Unit 1: Seeing and testing cells Microscopy and Quantitative Images Two GFP-filled vesicles 150 nm apart look like one blob in the best ordinary light microscope. Zooming in will not split them. Why not?
- Unit 1: Seeing and testing cells Experiments That Distinguish Mechanisms A pellet named 'mitochondria' is never only mitochondria. How do you find out what is really in it?
Unit 2 · Membranes and compartments
- Unit 2: Membranes and compartments Membrane Organization and Topology The outer half of a red blood cell's membrane carries about 1.6 double bonds per phospholipid. The inner half carries about 3.4. Who keeps them apart?
- Unit 2: Membranes and compartments Transport Across Membranes Which way will potassium flow if you hold a cell at −70 millivolts? Its concentrations alone will not tell you.
- Unit 2: Membranes and compartments Organelles as Distinct Environments In HeLa cells the mitochondrial matrix measured near pH 8 and the Golgi near pH 6.6. How does one cell keep both?
- Unit 2: Membranes and compartments Protein Sorting into Compartments Made in a test tube with no membranes, a secretory protein comes out longer than the one the cell secretes. Why?
- Unit 2: Membranes and compartments The Nuclear Envelope and Nuclear Transport Why does a protein that shuttles in and out of the nucleus pile up inside when one drug is added?
- Unit 2: Membranes and compartments Protein Quality Control and Organelle Turnover A starving yeast cell eats pieces of itself. Why does a mutant that cannot do so die sooner?
- Unit 2: Membranes and compartments Nuclear Architecture and Membraneless Compartments How does a nucleus keep things apart with no membranes inside it?
Unit 3 · Traffic and movement
- Unit 3: Traffic and movement Vesicle Budding, Targeting and Fusion A yeast mutant keeps making secretory enzymes at 37 °C but cannot release them. Where do they go?
- Unit 3: Traffic and movement The Secretory Pathway Label a pancreas cell's new proteins for a few minutes, then watch them move: what route do they take, and how do you know?
- Unit 3: Traffic and movement Endocytosis, Recycling and Degradation Why can a patient's cells grip cholesterol-carrying LDL normally and still leave it outside?
- Unit 3: Traffic and movement Cytoskeletal Polymers and Dynamics A microtubule in a dish of pure tubulin grows for minutes, then collapses many times faster. Why would a polymer be built to fail?
- Unit 3: Traffic and movement Molecular Motors and Cargo One kinesin molecule moves in 8-nanometre steps and spends one ATP on each. How was that measured?
- Unit 3: Traffic and movement Cell Shape, Migration and Cilia Four men had sperm that could not swim. Three could not clear mucus from their lungs either. One missing motor explained both.
Unit 4 · Division and cell loss
- Unit 4: Division and cell loss Cell-Cycle States and Control Logic Fuse a cell that is copying its DNA with one that has finished. Why does the finished nucleus refuse to copy again?
- Unit 4: Division and cell loss Checkpoints and Irreversible Transitions A yeast cell missing one gene keeps dividing after irradiation and dies. Hold it back with a drug, and it can repair the damage. What was the gene for?
- Unit 4: Division and cell loss Mitosis and Chromosome Segregation In the dividing cultured human cells measured, most spindle microtubules are not made at the centrosomes. So where do they come from?
- Unit 4: Division and cell loss Cytokinesis and Organelle Inheritance Push the spindle off-centre in a sea urchin blastomere, and the signal for the furrow moves with it before the furrow does.
- Unit 4: Division and cell loss Cell Death and Clearance In a developing worm, 131 of the cells made in the hermaphrodite body die on schedule. Who decides?
Unit 5 · Cells in tissues
- Unit 5: Cells in tissues Adhesion and the Extracellular Matrix Take the calcium away and a sheet of epithelial cells comes apart. What was the calcium holding together?
- Unit 5: Cells in tissues Epithelia and Tissue Organization The gut lining is one cell thick. How does it move glucose one way and keep the gut contents out?
- Unit 5: Cells in tissues Stem Cells and Tissue Renewal The lining of a mouse's small intestine is rebuilt every few days. Which cells do it, and how would you prove it?
- Unit 5: Cells in tissues Cell Identity, Cell State and Disease Most of the lining of an older person's healthy oesophagus can carry a mutation found in cancer. Why is it still healthy?
- Unit 5: Cells in tissues Designing a Cell Biology Experiment A thousand cells in one dish are not a thousand experiments. How many are they?