Molecular weight is the mass in grams of a mole of a chemical formula unit. The hypothesis was based on previous observation that the molecular weight of a substance influenced the rate of diffusion. In this study, the authors used several compounds to test their hypothesis, including potassium dichromate, methylene blue, and potassium permanganate. Read on to learn more about these compounds. We’ve also covered the effect of high blood pressure and fluorescent molecules’ shape on diffusion.
The rate of diffusion is proportional to the molecular weight of a substance. Lighter molecules are more diffuse and liquefiable than heavier ones. The inverse relationship between the mass and density of a substance is true for gaseous substances, too. Therefore, it is important to consider molecular weight when choosing a material for diffusion. As a rule of thumb, the lighter the molecule, the faster it will diffuse.
In experiments using fluorescent molecules, the shape of the molecule strongly affected the diffusion rate of the solute. For example, linear dextran moved slower than globular proteins. Similarly, parvalbumin was more diffuse than dextran-10k, despite their similar molecular weights. The shape of the solute also affects diffusion. Molecular weight, shape, and shape all affect the rate of diffusion.
Rate of diffusion
The concentration gradient in extracellular fluid determines the rate of diffusion of substances. Different substances will have different rates of diffusion depending on their molecular weight. Higher molecular weights will diffuse more quickly than lower ones. The closer the concentration gradient is to the equilibrium value, the slower the rate of diffusion. The heavier the molecule, the slower the rate of diffusion will be. Molecular weight affects the diffusion rate in two ways.
The methylene blue test showed that it diffraction is influenced by molecular weight. The lowest molecular weight substance was methylene blue. The other two substances had higher molecular weights. The lower molecular weight substance had the largest diameter, whereas the highest was potassium dichromate. The higher the molecular weight, the slower the rate of diffusion. In this study, methylene blue had the lowest mean rate of diffusion.
Effect of high blood pressure on diffusion
When high blood pressure is present, it affects the concentration gradient, which in turn accelerates the rate of diffusion. Diffusion occurs as the material moves through the membrane according to a concentration gradient. High blood pressure forces large quantities of dissolved substances and water out of the blood, increasing the concentration of protein in the urine. The effect is similar to that seen with drugs. Nevertheless, the effects of high blood pressure on the concentration gradient are not immediately apparent.
The experimental data are lower than the theoretical predictions, and the discrepancy between the two is a factor of two at Ph = 0.25. These results agree with the long-term tracer diffusion coefficients of hemoglobin and myoglobin. The short-time self-diffusion coefficient is estimated from the decay of the correlation function. This method of analysis can be adapted to other systems, including vivo.
Effect of shape of fluorescent molecule on diffusion
To understand the underlying principles of fluorescent molecule diffusion, one must first examine the fundamentals of its physics. Fluorescent molecules exhibit two types of diffusion: membrane diffusion and lateral diffusion. A membrane diffusion occurs at the interface between two different materials. For example, fluorescent molecules can diffuse from a single material to a mixture of two materials. Membrane diffusion takes place in a thin film between two surfaces.
The diffuse diffusion coefficient of a fluorescent molecule is dependent on the fluorescent dye’s shape, concentration, and topological properties. Fluorescent dyes of different shapes, like bBodipy, can produce erroneous values. The reason is that the fluorescent probes can change their topological properties, which complicates prediction. These effects were addressed by a liposome-based method. A model composed of identical fluorescent molecules cannot account for these specific effects. Moreover, individual vesicles have different sizes, topological alterations, and compositional heterogeneity.