What are the key mechanisms involved in molecular transport across cell membranes?
The key mechanisms involved in molecular transport across cell membranes are passive transport (including diffusion and facilitated diffusion) and active transport. Passive transport involves movement of molecules down their concentration gradient without energy, while active transport requires energy (ATP) to move molecules against their concentration gradient.
What factors influence the rate of molecular transport in porous materials?
The rate of molecular transport in porous materials is influenced by pore size, pore connectivity, material porosity, temperature, pressure, and the molecular properties of the transported substance such as size, shape, and diffusion coefficients.
How does temperature affect molecular transport in fluids?
Temperature affects molecular transport in fluids by influencing the kinetic energy of molecules; as temperature increases, molecules move faster, enhancing diffusion and reducing viscosity, which in turn accelerates molecular transport. Conversely, lower temperatures decrease kinetic energy, leading to slower molecular movement and reduced transport rates.
How do molecular transport processes impact drug delivery systems?
Molecular transport processes, such as diffusion, osmosis, and active transport, directly influence the efficiency and targeting of drug delivery systems by controlling the rate and extent to which drugs reach their intended site of action, thereby affecting the drug's bioavailability, therapeutic efficacy, and potential side effects.
What are common applications of molecular transport in environmental engineering?
Common applications of molecular transport in environmental engineering include the remediation of contaminated soil and groundwater, the design of wastewater treatment processes, air pollution control, and the development of membranes for desalination and water purification systems.