The specimen room. Turn them yourself.

Cells

• Human cell 3D model

  A cut-away animal cell: the nucleus in purple, mitochondria in orange, in the textbook colours we use in every video.

  Common human cells are about 10 to 20 micrometres across.

  Source: Milo & Phillips, Cell Biology by the Numbers: “How big is a human cell?”

  Model: “Human Cell” by Shihab (Sketchfab, CC BY 4.0), recoloured to textbook colours, compressed

• Mitochondrion 3D model

  The power station of the cell, once a free-living bacterium. Its folded inner membrane holds the ATP synthase motors.

  A typical mitochondrion is roughly 2 micrometres long and 1 micrometre wide.

  Source: Milo & Phillips, Cell Biology by the Numbers: “How big are mitochondria?”

  Model: “Mitochondria” by CAPTAAINRO (Sketchfab, CC BY 4.0), recoloured to textbook colours, compressed

Human body

• Red blood cells 3D model

  The most common cell in your body, shaped like a dimpled disc.

  Red blood cells are 7 to 8 micrometres across and have no nucleus.

  Source: Milo & Phillips, Cell Biology by the Numbers: “How big is a human cell?”

  Model: “Red Blood Cells (Erythrocytes)” by _Bonehead14 (Sketchfab, CC BY 4.0), compressed

• Neuron 3D model

  A nerve cell: branching dendrites collect signals, one long axon sends them on.

  The longest neurons in your body are over a metre long.

  Source: Milo & Phillips, Cell Biology by the Numbers: “How big is a human cell?”

  Model: “Neuron” by Versal (Sketchfab, CC BY 4.0), recoloured to textbook colours, compressed

Microbes

• Bacterium 3D model

  A rod-shaped bacterium with its hair-like pili.

  An E. coli cell, a typical rod-shaped bacterium, is about 1 micrometre wide and 2 micrometres long.

  Source: Milo & Phillips, Cell Biology by the Numbers: “How big is an E. coli cell?”

  Model: “Bacterium” by andrewfrueh (Sketchfab, CC BY 4.0), recoloured to textbook colours, compressed

• Coronavirus 3D model

  A coronavirus particle, covered in the spike proteins that give the family its crown-like name.

  Model: “Corona Virus 3D Model” by Akshat (Sketchfab, CC BY 4.0), compressed

Animals

• Water bear (tardigrade) 3D model

  Our own 3D water bear, the one from our videos: a pleated body, four pairs of stubby clawed legs and a tube-like mouth. Watch it walk.

  A water bear is about half a millimetre long, and some have survived ten days in open space.

  Source: Cellula Magna: The animal that survived space (sources listed there)

Molecules

• DNA double helix 3D model

  Two backbones wound around each other, with the base pairs that spell out the genetic code between them.

  Model: “DNA” by Holoxica (Sketchfab, CC BY 4.0), recoloured to textbook colours, compressed

• ATP synthase Real data

  The real human ATP synthase. The green rotor turns inside the ring, and each turn makes ATP, the energy molecule every cell spends.

  In lab tests its rotor has been clocked at more than a hundred turns a second.

  Source: Protein Data Bank 8H9S (Lai et al. 2023, Molecular Cell)

• Kinesin on tubulin Real data

  A kinesin-1 motor domain (amber) standing on a tubulin dimer (greens), the step it takes along the cell’s microtubule roads.

  Kinesin advances about 8 nanometres a step, up to around a hundred steps a second.

  Source: Protein Data Bank 4HNA

• Tubulin dimer Real data

  Alpha and beta tubulin, the paired building block that stacks into microtubules.

  Each αβ-tubulin dimer is 8 nanometres long.

  Source: Protein Data Bank 1JFF

• ATP Real data

  Adenosine triphosphate, ball and stick: carbon grey, oxygen red, nitrogen blue, phosphorus orange, hydrogen white.

  By some estimates you remake roughly your own body weight of ATP every day.

  Source: PubChem CID 5957; Törnroth-Horsefield & Neutze 2008, PNAS