Bionanotechnology

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Bionanotechnology
The principles of physics, as far as I can see,
do not speak against the possibility of
maneuvering things atom by atom. It is not an
attempt to violate any laws it is something, in
principle, that can be done but in practice, it
has not been done because we are too big.Richard
Feynman (1959 talk at Cal Tech). I am inspired by
the biological phenomena in which chemical forces
are used in repetitious fashion to produce all
kinds of weird effects (one of which is the
author).Richard Feynman
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Bionanotechnology
The principles of physics, as far as I can see,
do not speak against the possibility of
maneuvering things atom by atom. It is not an
attempt to violate any laws it is something, in
principle, that can be done but in practice, it
has not been done because we are too big.Richard
Feynman (1959 talk at Cal Tech). I am inspired by
the biological phenomena in which chemical forces
are used in repetitious fashion to produce all
kinds of weird effects (one of which is the
author).Richard Feynman
As we read these words, 10,000 different
nanomachines are at work inside each of our
bodies.
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These bio-nanomachines underpin the many
processes of life digesting, breathing, growing,
repairing, sensing, responding.
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• These bio-nanomachines underpin the many
  processes of life digesting, breathing, growing,
  repairing, sensing, responding.
• Many of these biological nanomachines still
  perform their atomic-sized functions when
  isolated from our bodies.

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• These bio-nanomachines underpin the many
  processes of life digesting, breathing, growing,
  repairing, sensing, responding.
• Many of these biological nanomachines still
  perform their atomic-sized functions when
  isolated from our bodies.
• Natural digestive enzymes, like pepsin
  lysozyme in laundry detergents digest away
  stains.
• Amalyses convert powdery starch to sweet corn
  syrup on an industrial scale.
• Genetic engineering much biotechnology is
  based on DNA and its manipulation by
  nanomachines.

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Differences between the Everyday World and the
Bio-Nano World partial reminder

• Gravity weight are often negligible in the Nano
  Worldexamples include Brownian motion and
  intermolecular forces (often crucial in
  bionanomachines).

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Differences between the Everyday World and the
Bio-Nano World partial reminder

• Gravity weight are often negligible in the Nano
  Worldexamples include Brownian motion and
  intermolecular forces (often crucial in
  bionanomachines).
• Forces can turn on and off very quickly (due to
  drag effects)examples include bacterial cells
  with long, corkscrew flagella.

The cells stop moving forward instantlyin less
than an atomic radiuswhen the flagellum stops
propelling the cell.
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• Atomic granularity shows up in the
  nanoworldnano-scale biomachines, such as rotary
  motors, are unlike macroscopic rotary motors.
  Nano-motors show discrete turns.

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• Thermal motion is important at the nano-scale
  i.e., Brownian motion.

• Individual parts of biomachines depend on random
  motion diffusion (very different from everyday
  machines). The bulk of work performed in cells
  is done in the context of random, diffusive
  motion.
• Diffusive motion is fast at the cellular level a
  protein released in one part of a cell is likely
  to be at any location in the cell within 0.01
  seconds two molecules on opposite sides of a
  cell will interact within 1 second!

5. Bionanomachines require a water environment.
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Examples of Bionanotechnology

• Vorticella valerias spasmoneme. Vorticella is a
  one-celled protozoan, at home in pond water,
  rooted to the bottom of the pond

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Examples of Bionanotechnology

• Vorticella valerias spasmoneme. Vorticella is a
  one-celled protozoan, at home in pond water,
  rooted to the bottom of the pond

30-50 µm
Cell body (upside down bell shaped) with cilia
along the upper edge for feeding.
Substrate (leaf, rock)
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Examples of Bionanotechnology

• Vorticella valerias spasmoneme. Vorticella is a
  one-celled protozoan, at home in pond water,
  rooted to the bottom of the pond

30-50 µm
Cell body (upside down bell shaped) with cilia
along the upper edge for feeding.
Stalk (20-300 µm)
Substrate (leaf, rock)
When threatened, Vorticella collapses its stalk.
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What causes this reversible collapse? Not water
transport in/out of cells (of course).
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What causes this reversible collapse? Not water
transport in/out of cells (of course). Current
theory Coulomb repulsion
between protein filaments in Vorticellas stalk
causes it to extend. How? Charged proteins
(spasmins) in the stalk.
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_
_
_
_
Each charged spasmin is composed of 180 amino
acid residues, some of which are polar (charged).
_
_
_
30 nm
_
Stalk
3 nm
The negatively-charged spasmins repel each other
and the stalk extends. When the stalk is in the
presence of calcium, the stalk collapses Ca
ions shield the polar residues.
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Polar residues (-)
Ca()
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• Biomolecular Rotary Motors

• F1-ATPase (F1- Adenosine Triphophase Synthase)
• ATP Synthase (F0F1)
• These motors occur in cell walls, where they are
  mountedthey transmit rotational torque and power
  across the cell wall.

The long flagellar motor (pink, at left) of
Escherichia coli, built for propulsion, spans the
cell wall of a bacterium and turns the
corkscrew-shaped flagellum in this illustration
from Goodsell's Bionanotechnology." A second
rotary motor of the cell, ATP synthase, also
spans the cell wall (red, at right). The flagella
rotate at rates of more than 100,000 rpm.
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F1-ATPase
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• F1-ATPase as a rotary motorexperimental
  observations

• A buffer solution with 2 mM Na2ATP fuels
  rotation
• A buffer solution with 10 mM NaN3 (sodium azide)
  stops the rotation.
• The molecular power source is hydrolysis of ATP
  molecules 240 pNnm 240 10-21 Joules.
• Energy for 1 turn 119 125 pNnm
• Efficiency of these motors is 50 (120
  pNnm)/(240 pNnm)

A good engine and power source for NEMS
(nano-electromechanical systems)
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• Bio-molecular rotary motor powered propellers.
• 80 nm Ni post from array.
• Schematic view of F1-ATPase molecular motor.
• Array of Ni propellers, 750 nm 1400 nm in
  length, 150 nm in diameter.
• Schematic view of one assembled device from
  array.

Wolf, figure 3.4
Rotation in fluid of propeller (0.8 8.3 rps)
fueled with ATP is 50 efficient.
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• ii. ATP Synthase (F0F1)experimental observations
  
• bio-molecular motor produces a torque of 40
  pNnm
• rotation occurs when ambient solution contains 5
  mM Mg ATP
• Rotations in the range 0.2 3.5 rotations per
  second

There is no detailed understanding of this motor,
as of yet.
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Rotor
Wolf, figure 3.3
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3. Ion Channels in cell walls
Bio-nano-transistors
Transistor starts/stops a current flow
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3. Ion Channels in cell walls
Bio-nano-transistors
Transistor starts/stops a current flow
Example Voltage Gated Potassium Channel in
Neurons and other excitable cells. The potassium
channel is embedded in the cell wall and it
opens/closes to allow potassium ions to pass
through.