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Bacteria move around using motors that are smaller than 1,000th the width of a human hair and which rotate faster than a Formula 1 engine. Human cells also contain linear motors which transport cargo and help in cell division. The scientists behind this exhibit investigate how these mini motors work and are building their own.
crystal structure of the motor protein kinesin shows that it has
two identical "feet"(green and blue). The fuel for the motor is ATP
(adenosine triphosphate). Fuel molecules are shown in red. Rendered
with the UCSF Chimera package.
Due to their small size, molecular motors operate in an
environment with very high friction. For humans, this would be
equivalent to swimming in treacle. The friction levels lead to
challenges and solutions which are removed from our everyday
experience yet are happening in our cells all the time.
How it works
Man-made machines and computer chips have been shrinking in size
but we are reaching the limits of what can be made using current
technology. In order to make smaller machines we will have to start
using bottom up construction with molecular components that
Self-assembled motors already exist in the natural world. There
are rotary and linear mini motors which are efficient (~50-100%)
and take part in a wide range of processes from movement of
organisms to cell division. By understanding how these motors work
we can then use them to build and power molecular-scale
We can also try to build our own mini motors. DNA is an ideal
material to do this as the interactions between synthetic DNA
molecules can be controlled to program how they assemble.
Increasingly complex structures have been designed and made by
self-assembly including geometric figures, containers and walking
Lead image: A reconstruction of the
bacterial flagellar motor from Salmonella enterica using electron
microscopy data. The bacterial flagellar motor crosses the cell
membrane and uses the difference in proton concentration inside and
outside the cell to power its rotation. A long helical tail is
attached to the motor and acts like a propeller allowing the
bacteria to swim. Credit: Rendered with the UCSF Chimera