In molecules, AQ (TR:4), or “AnthraQuinone”, molecular formula: C14H8O2, is DTA-like animate molecule, with two oxygen feet, which has the ability, when powered, to carry “loads” of CO2 molecules.

Overview
In 2007, Ludwig Bartels, expanding on his earlier DTA experiments (2005), began investigating so-called "molecular carriers", specifically by doing STM studies on AnthraQuinone (AQ) (Ѻ), a DTA-like molecule, formula C14H8O2, with two oxygen feet. The following shows an "AQ molecule" attaching to or carrying a CO2 molecule (or two CO2 molecules) during diffusion along the Cu(111) high-symmetry direction by means of individual steps: [1]

AQ molecule (carrying load)

Bartels found that carrying more load, e.g. 2 or three CO2 molecule, slows the carrier down, just as a human is slowed down when carrying more bundles.

The following is a gif animation of DQ carrying its CO2 bundles:
AQ carrying
(add)

See also
ATP
DNA
● Kinesin
● Myosin
● Retinal | Retinal molecule | ABC model
RNA
Virus | Virus molecule

References
1. Leigh, David A., Lewandowska, Urszula, Lewandowski, Bartosz, and Wilson Miriam R. (2014). “Synthetic Molecular Walkers”, in: Molecular Machines and Motors: Recent Advances and Perspectives (editors: Alberto Credi, Serena Silvi, Margherita Venturi) (§4:111-38; pgs. 126-27). Springer.

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