Molecular weight, carrier mobility

Mass transfer (the C term), which involves collisions and interactions between molecules, applies differently to both packed and capillary columns. Packed columns are mostly filled with stationary phase so liquid phase diffusion dominates. The mass transfer is minimized by using a small mass of low-viscosity liquid phase. Capillary columns are mostly filled with mobile phase, so mass transfer is important in both the gas and liquid phases. A small mass of low-viscosity liquid phase combined with a low-molecular weight carrier gas will minimize this term. 

These mobile electron carriers are relatively low-molecular-weight proteins and are both linked to the PS-1 reaction-center complex by electrostatic forces. Plastocyanin is located on the lumen side and is the electron donor to P700, while ferredoxin is located on the stroma side and receives electrons from the terminal, membrane-bound iron-sulfur proteins FeS-A/B. Water is the ultimate source of electrons for plastocyanin reduction. The electron from water is generated by its oxidation by photosystem 11, and transferred by way of cytochrome/in the cytochrome b(f complex. Reduction of NADP by ferredoxin requires mediation by the enzyme ferredoxin-NADP -reductase orFNR. Figure 1, right is a schematic representation of the relationship of the PS-1 reaction center to the peripheral electron carriers plastocyanin and ferredoxin as well as the protein catalyst ferredoxin-NADP -reductase. 

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