The main theme of the poem is the regret and sorrow the narrator feels about the end of his relationship with the woman in the poem, described only as "you." The poem suggests that the woman may well have been the one to break off the affair: Pale grew thy cheek and col
Answer: the membrane channel
Explanation:
In passive diffusion, the small water molecules can move across the phospholipid bilayer seen in blue. This layer acts as a semi-permeable or selectively permeable membrane; its hydrophilic heads are attracted to water (seen facing outwards) while its water-repellent hydrophobic tails face towards each other- allowing molecules of water to diffuse across the membrane along the concentration gradient.
Thus the water will move from an area of high concentration to an area of low concentration, until the system reaches a steady state called equilibrium- after this, there will be no net movement of water. Similarly via osmosis, the water passes through the membrane due to the difference in osmotic pressure on either side of the phospholipid bilayer this means that the water moves from regions of high osmotic pressure/concentration to regions of low pressure/ concentration to a steady state.
The dialysis tubing mimics a semi permeable membrane; it only allows water and small molecules of iodine to cross into the bag containing starch. The tubing is impermeable to starch; these large molecules require the aid of protein omplexes called membrane channels, in order to move across the membrane and against the concentration gradient.
Lipid bilayer model was proposed for its structure but it was modified and new structure is according to fluid mosaic model. Plasma membrane is selectively permible as it selects small molecules like lipid etc (composition is also of lipid and as solubility principle like dissolve like) so large and charged molecules like plasma and ion can't pass through it. Lipid are in form of layer so at the chain when ever other phosphate group attach the place conjugate molecule (phospholipid ) formed
it's a summary of the number of individuals of each age in the population. Age structure is useful in understanding and predicting population growth. An understanding of population age structure is critically important to industries that harvest living organisms.
hope that i helped :)