Download Brain regions related to quantum coherence

Brain regions related to quantum coherence
Research since 2007 has shown that quantum coherence is utilised in increasing the
efficiency of energy transfer in photosynthetic systems. What has not been
emphasised in the discussion of this research is that the mitochondria that produce
energy in animals cells probably evolved from the same type of bacteria as the
chloroplasts of modern plant systems. Evolution tends to retain features so the
likelihood of quantum coherence being utilised in human cells including neurons looks
quite high. The high levels of activity and integration associated with conscious
processing looks a possible trigger for requiring a more efficient form of energy
transport.
The beginning for organic energy
Photosynthesis, by which sunlight is converted into energy for organisms was the first type of
organic energy to appear. With the eukaryotic cells, such as those found in modern animals
and plants, specialised membranes in energy-converting organelles perform this function.
These organelles are mitochondria in animal cells, and the quite similar chloroplasts in plants.
Both mitochondria and chloroplasts are characterised by a large amounts of internal
membrane, and these membranes are involved in the transfer of electrons and the production
of ATP. It is thought that both mitochondria and chloroplasts evolved from unicellular
prokaryote cells that were subsequently engulfed by primitive eukaryote cells.
Chemiosotic coupling
Mitochondria, chloroplasts and prokaryotes use a common pathway, known as chemiosmotic
coupling, to generate energy. This name refers to the connection between the generation of
ATP and membrane transport. Electron transfer provides most of the energy for living things.
Electrons move spontaneously between molecules with a low affinity for electrons, to
molecules with a high affinity for electrons. The process of chemiosmotic coupling is
performed by protein complexes embedded in membranes. A proton (H+) gradient over the
membrane allows the synthesis of ATP. ATP is used as a store of energy in cells to drive
chemical reactions within the cell. Its energy can be released by giving up terminal phosphate
which changes it into ADP. Phosphorylation subsequently recycles the ADP back into the
ATP energy store.
High-energy electrons are derived from processes such as sunlight for photosynthesis, or the
oxidation of food-derived molecules in animals. These high-energy electrons are transferred
by means of electron carriers embedded in the membrane. Electron transfer releases energy,
which pumps protons across the membrane, creating a proton gradient. This gradient
represents stored energy, which drives an enzyme to synthesise ATP from ADP and
phosphate.
Electron transfer provides most of the energy for living things. Electrons move spontaneously
between molecules with a low affinity for electrons, to molecules with a high affinity for
electrons. Each carrier can interact only with the carrier adjacent to it. Electrons can move
along covalent bonds. They can also jump across a gap of as much as 2 nm. This jump is
achieved by quantum tunnelling. The drop in redox potential between two electron carriers is
proportional to the free energy released when an electron transfers between them.
Mitochondria
The mitochondria produce most of the ATP in an animal cell. Energy is harnessed by an
electron-transport chain in the mitochondria’s inner membrane. A large amount of free energy
is released when protons (H+) flows back across the inner membrane to allow the production
of ATP by the ATP synthase. This provides a high level of free energy to drive the whole cell’s
requirements.
ATP Synthase: an ancient enzyme
The ATP synthase is of ancient origin. The same enzyme is found in mitochondria,
chloroplasts of plants and algae and the plasma membrane of bacteria. Mitochondria convert
energy from chemical fuels, while chloroplasts convert energy from sunlight. With
mitochondria, electrons released from carbohydrate food molecules are transferred through
the organelle’s membrane by a chain of electron carriers. They release energy moving from a
high energy to a low energy state. Electrons are transferred by diffusing molecules that attract
an electron at one location and shed it at another. This is known as an electron-transport
chain and is associated with the inner membrane of the mitochondria.
Chloroplasts
Several of the main components of the chloroplast are similar to those of the mitochondria,
but the chloroplast membrane also has some components not found in the mitochondria,
notably the photosystems of the chloroplast where light is captured by chlorophyll to drive the
transfer of electrons. The plasma membranes of most bacteria contain an ATP synthase
similar to those found in mitochondria. An electron-transport chain harvests energy by
pumping H+ out of the cell, establishes a proton gradient, and thus drives the ATP synthase
to produce ATP.
In the chloroplasts, ATP provides fuel for organic molecules. The mechanisms involved in
light-driven photosynthesis are the same in principle to those used by the membranes of
mitochondria. Chloroplasts are contained within two concentric membranes. They use the
same type of chemiosmotic processing as mitochondria, and although much larger than
mitochondria, they are organised on the same principles, with transport proteins embedded in
the less permeable inner membrane. The inner membrane encloses a space called the
stroma, which is analogous to the enzyme containing matrix in mitochondria, with both
spaces containing enzymes.
However, the chloroplasts have a third distinctive membrane not found in mitochondria. This
is the thylakoid membrane which contains light-capturing systems, electron-transport chains
and the ATP synthase. The first stage of photosynthesis is that the energy of sunlight
energises an electron in the chlorophyll pigment, which allows the electron to move along an
electron-transport-chain in the thylakoid membrane. This is analogous to the electrontransport-chain found in mitochondria. During the chloroplast’s electron transport, H+ is
pumped across the thylakoid membrane producing a proton gradient which drives the
synthesis of ATP, which in turn fuels the subsequent conversion of carbon dioxide into
carbohydrate. An effective method of making ATP is thought to have arisen early in evolution,
and has been conserved with only small variations since then. The crucial components are
ATP synthase, redox driven H+ pumps and photosystems arise.
A photosystem, as used in photosynthesis, comprises two components, an antenna complex
and a reaction centre. The antenna system funnels electron energy into the reaction centre.
These multiprotein photosystems catalyze the conversion of light energy captured by excited
chlorophyl molecules. A photosystem has two closely linked components, an antenna system
with pigment molecules that capture light energy and a reaction centre. The antennae system
feed energy to the reaction centre. The antenna which captures the sunlight comprises a
number of membrane protein complexes, called light-harvesting complexes. The reaction
centre consists of a complex of proteins and chlorophyll molecules which convert the light
energy into chemical energy.
CONCLUSION: Since 2007 research has shown that quantum coherence is functional in
increasing the efficiency of energy transfer in photosynthetic systems, including multicellular
plants at room temperature. What has never been emphasised in discussions about this type
of research is that similar systems to those utilising quantum coherence in plants are also
present, in the form of mitochondria, in animal cells including neurons. Evolution has a
tendency to retain features, so there is no reason to believe that it would not have retained
the ability to utilise quantum coherence in animal cells, and thus in neurons. The intensive
activity and integration involved in conscious processing thus looks a prime candidate for the
more efficient energy transfer offered by quantum coherence.