538
11 Biomolecular Structure and Interactions
Fig. 11.4 Atomic-ForceMicroscope Image of a
plasmid DNA (pUC19). The
image is from Dalong Pang,
Alain R. Thierry, and Anatoly
Dritschilol, DNA studies
using atomic force
microscopy: capabilities for
measurement of short DNA
fragments, Front. Mol.
Biosci. (29 January 2015)
extends over tens of nanometers. The Rayleigh limit for the microwaves is avoided
by generating and detecting the electric field in the needle’s microwave near-zone.
Resolutions on the order of a few nanometers are possible.
11.9 Biomolecular Motor
In order for life systems to be able to generate order, those systems have developed
the ability to do work. This includes molecular motors in viruses, the transport
of molecules within cells, the movement of celia, flagella, pseudopodia, pressure
pumps, and muscle contraction. For higher-level organisms, movement helps gather
food, interact with other organisms, and explore and exploit the environment. At the
nanoscale, such organisms use biomolecular motors to effect movement.
Molecular motors have become an essential mechanism in life systems on Earth,
from the smallest organisms, viruses, to us. The activity of life necessarily involves
the use of force over a distance to create order. Force times distance is work. That
means the molecular motor transforms stored energy into work.
Physically, a motor is any device for transforming some form of energy into
mechanical motion. In principle, this transformation can be 100% efficient. Electric
motors with magnetic bearings and superconducting currents can transform energy
stored in electrical or magnetic pressure into the motion with no loss into heat.
However, the motors used in biological systems use energy stored in the molecular
bonds, typically the energy in ATP, as a source within cells. The rotation of flagella
11 Biomolecular Structure and Interactions
Fig. 11.4 Atomic-ForceMicroscope Image of a
plasmid DNA (pUC19). The
image is from Dalong Pang,
Alain R. Thierry, and Anatoly
Dritschilol, DNA studies
using atomic force
microscopy: capabilities for
measurement of short DNA
fragments, Front. Mol.
Biosci. (29 January 2015)
extends over tens of nanometers. The Rayleigh limit for the microwaves is avoided
by generating and detecting the electric field in the needle’s microwave near-zone.
Resolutions on the order of a few nanometers are possible.
11.9 Biomolecular Motor
In order for life systems to be able to generate order, those systems have developed
the ability to do work. This includes molecular motors in viruses, the transport
of molecules within cells, the movement of celia, flagella, pseudopodia, pressure
pumps, and muscle contraction. For higher-level organisms, movement helps gather
food, interact with other organisms, and explore and exploit the environment. At the
nanoscale, such organisms use biomolecular motors to effect movement.
Molecular motors have become an essential mechanism in life systems on Earth,
from the smallest organisms, viruses, to us. The activity of life necessarily involves
the use of force over a distance to create order. Force times distance is work. That
means the molecular motor transforms stored energy into work.
Physically, a motor is any device for transforming some form of energy into
mechanical motion. In principle, this transformation can be 100% efficient. Electric
motors with magnetic bearings and superconducting currents can transform energy
stored in electrical or magnetic pressure into the motion with no loss into heat.
However, the motors used in biological systems use energy stored in the molecular
bonds, typically the energy in ATP, as a source within cells. The rotation of flagella