Run And Tumble Bacterial Swimming
This animation shows how E. coli, a peritrichous bacterium, moves using multiple flagella. It contrasts the RUN phase, where counterclockwise motor rotation bundles flagella into a propeller for straight swimming, with the TUMBLE phase, where reversed rotation scatters the bundle and reorients the cell. The sequence highlights how alternating runs and tumbles let bacteria navigate their environment, useful for students studying microbiology, cell motility, or biophysics.
16:9 · every frame verified for overlaps, spacing and edges before rendering
The prompt that made it
Create a scientifically accurate educational animation explaining how a peritrichous bacterium such as Escherichia coli moves using its flagella. The animation must clearly distinguish between RUN and TUMBLE. SCENE 1 — BACTERIUM AT REST Show a rod-shaped bacterium with many flagella distributed over its entire surface. The bacterium is stationary. Show the label: "Bactérie péritriche". SCENE 2 — RUN: FORWARD MOVEMENT Show the flagellar motors rotating counterclockwise when viewed from outside the bacterial cell. The flagellar filaments rotate and become organized into a coherent bundle behind the bacterium. The bundle acts as a propeller and pushes the bacterium forward. Show the bacterium moving approximately in a straight line. Show a large arrow indicating the direction of movement. Display: "Rotation antihoraire → faisceau de flagelles → déplacement vers l'avant" IMPORTANT: The flagella must be shown rotating around their axes. They must NOT look like arms simply waving back and forth. SCENE 3 — TUMBLE: CHANGE OF DIRECTION Show some flagellar motors reversing their direction of rotation. The coherent flagellar bundle breaks apart. The individual flagella become separated and point in different directions. The bacterium stops moving in a straight line and rapidly changes its orientation. Display: "Inversion de la rotation → dispersion des flagelles → réorientation" SCENE 4 — NEW RUN After the tumble, show the flagella becoming coordinated again and forming a new bundle behind the bacterium. The bacterium begins swimming forward in a new direction. Show a new arrow indicating the new direction. Display: "Nouvelle coordination → nouveau déplacement" SCENE 5 — FINAL SUMMARY Show the complete sequence visually: RUN ↓ Rotation coordonnée des flagelles ↓ Formation d'un faisceau ↓ Déplacement rectiligne TUMBLE ↓ Inversion de rotation ↓ Dispersion des flagelles ↓ Réorientation NEW RUN ↓ Formation d'un nouveau faisceau ↓ Déplacement dans une nouvelle direction SCIENTIFIC REQUIREMENTS: - Use a realistic rod-shaped bacterial cell. - Show numerous flagella distributed over the entire cell surface. - Clearly show the difference between flagellar rotation and simple waving. - Make the formation and disappearance of the flagellar bundle clearly visible. - Do not show the bacterium continuously spinning around its own axis during the RUN. - Use slow motion during the flagellar rotation and during the transition from RUN to TUMBLE. - Use clear arrows to show the direction of bacterial movement. - Use French scientific labels. - Add a clear French voice-over explaining the mechanism. - Target audience: university-level biology/SVT students. - Duration: 60–90 seconds. - Clean 3D scientific animation style.
Make the next one in this series
- Show how chemotaxis biases run length toward higher attractant concentration
- Animate the flagellar motor's rotary structure and proton-motive force in detail
- Compare peritrichous flagellar bundling to polar flagellum swimming in other bacteria
