Chirality and Life

Abstract

Chirality, meaning handedness, pervades much of modern science, from the physics of elementary particles to the chemistry of life. The amino acids and sugars from which the central molecules of life-proteins and nucleic acids-are constructed exhibit homochirality, which is expected to be a key biosignature in astrobiology. This article provides a brief review of molecular chirality and its significance for the detection of extant or extinct life on other worlds. Fundamental symmetry aspects are emphasized since these bring intrinsic physical properties of the universe to bear on the problem of the origin and role of homochirality in the living world.

Review Article: Immobilized Molecules Using Biomaterials and Nanobiotechnology

“…They estimated that it is necessary to drill to a depth of 1.5 to 2 m to detect the amino acid signature of life that became extinct about three billion years ago. A microfabricated capillary [83] electrophoresis device (kind of new immobilization technology) for amino acid chirality determination was developed for extraterrestrial exploration [84]. Recently, antibody microarray, a new immobilization technology that kept the stability of antibody under space environment allowed it to be applied for planetary exploration Exomars mission [85].…”

Two‐Photon Absorption Circular Dichroism: A New Twist in Nonlinear Spectroscopy

“…[1] Because the specificity of ligand-receptor interactions plays a dominant role in life processes, a better understanding of the chiroptical properties of optically active molecules has been fundamental for all studies in biological activity, essentially those associated with the origin of life itself. [2] Molecules that are not superimposable on their mirror image, such as pure enantiomers, present differences in linear absorption coefficients and refractive indices for left and right circularly polarized light. The former effect is the so-called circular dichroism (CD), whereas the latter is known as optical rotation (OR).…”

Stirring competes with chemical induction in chiral selection of soft matter aggregates

“…In particular, one anticipates that achiral substances can be transformed, at most, into a racemic mixture of equally represented enantiomers, or into an enantiopure system with equal probability for the two enantiomers. Apart from the handedness imparted by proto-chiral organizing surfaces 3 , oriented reacting interfaces 4 , and aligning 5 or confining 6 boundaries, the balance above may be broken under the intervention of one within a few physical forces of signed helicity 7,8 , or through the effect of a chiral chemical modifier. In general terms, there is still the pending issue of whether a chiral physical force may be opposed in an effective way to a chiral chemical intervention.…”