Related Experiment Video
Updated: Jun 29, 2026
06:08
Biophysical Characterization of Flagellar Motor Functions
Published on: January 18, 2017
Thinking about flagellar oscillation
1Division of Biology, California Institute of Technology, Pasadena, California, USA. brokawc@caltech.edu
Cell Motility and the Cytoskeleton
|October 2, 2008
Summary
Understanding cilia and flagella bending requires further research into dynein motor activity. Key questions involve how dynein-driven sliding causes oscillatory bending and bend propagation.
Area of Science:
- Cell Biology
- Biophysics
Background:
- Cilia and flagella bending is driven by dynein motor enzymes causing microtubular outer doublet sliding.
- The precise mechanisms by which dynein activity leads to oscillatory bending remain incompletely understood.
Purpose of the Study:
- To review the outstanding questions regarding dynein-driven sliding in cilia and flagella motility.
- To explore the requirements for oscillatory bending and bend propagation.
Main Methods:
- This is a review article, synthesizing existing knowledge and posing questions.
- It does not present new experimental data but analyzes theoretical requirements.
Main Results:
- One mode of dynein activity (active forward) is characterized, but an alternative mode (inactive or reverse) is likely necessary for oscillation.
- Questions remain about how mode switching occurs (curvature, sliding direction, or both) and if reciprocal inhibition is involved.
Conclusions:
- Further investigation is needed to understand dynein-driven sliding for oscillatory bending.
- Mechanisms for self-organization, reciprocal inhibition, and inter-dynein interactions are critical for bend propagation and metachronal coordination.
Related Concept Videos
01:18Flagella and Motility in Bacteria
Flagella are specialized, thread-like structures that extend from a bacteria's cell envelope. They play a crucial role in motility and chemotaxis. Their structural organization and functioning exemplify sophisticated biological engineering, enabling bacterial survival and adaptability in diverse environments.Structure of the FlagellumA bacterial flagellum consists of three key components: the filament, the hook, and basal body. The filament, a long, helical structure composed of repeating...
01:06Forced Oscillations
When an oscillator is forced with a periodic driving force, the motion may seem chaotic. The motions of such oscillators are known as transients. After the transients die out, the oscillator reaches a steady state, where the motion is periodic, and the displacement is determined.
01:04Oscillations about an Equilibrium Position
Stability is an important concept in oscillation. If an equilibrium point is stable, a slight disturbance of an object that is initially at the stable equilibrium point will cause the object to oscillate around that point. For an unstable equilibrium point, if the object is disturbed slightly, it will not return to the equilibrium point. There are three conditions for equilibrium points—stable, unstable, and half-stable. A half-stable equilibrium point is also unstable, but is named so because...
01:07Damped Oscillations
In the real world, oscillations seldom follow true simple harmonic motion. A system that continues its motion indefinitely without losing its amplitude is termed undamped. However, friction of some sort usually dampens the motion, so it fades away or needs more force to continue. For example, a guitar string stops oscillating a few seconds after being plucked. Similarly, one must continually push a swing to keep a child swinging on a playground.
Although friction and other non-conservative...
Although friction and other non-conservative...
01:30Oscillations In An LC Circuit
An idealized LC circuit of zero resistance can oscillate without any source of emf by shifting the energy stored in the circuit between the electric and magnetic fields. In such an LC circuit, if the capacitor contains a charge q before the switch is closed, then all the energy of the circuit is initially stored in the electric field of the capacitor. This energy is given by
01:05Mechanism of Ciliary Motion
The ciliary structures were first seen in 1647 by Antonie Leeuwenhoek while observing the protozoans. In lower organisms, these appendages are responsible for cell movement, while in higher organisms, these appendages help in the movement of the extracellular fluids within the body cavities.
The cilia are made up of microtubules in a 9+2 arrangement, with nine microtubule doublet ring bundles, surrounding a pair of central singlet microtubule bundles. The doublet microtubule bundles are...
The cilia are made up of microtubules in a 9+2 arrangement, with nine microtubule doublet ring bundles, surrounding a pair of central singlet microtubule bundles. The doublet microtubule bundles are...