1. Why does osmosis occur in cells?
- Water moves through a permeable membrane in osmosis because there is a balanced concentration gradient across the membrane of solute and solvent. The solute has moved to balance the concentration on both sides of the membrane to achieve this balance.
2. What substances, other than water, readily move across the capillary membranes in both directions?
- Only the smallest molecules like water, carbon dioxide, and oxygen can freely diffuse across cell membranes. Larger molecules or charged molecules often require an input of energy to be transported into the cell. Even when equilibrium is reached, particles do not stop moving across the cell membrane.
3 why do proteins remain more abundant in the plasma?
- Albumin is the most abundant protein in the blood and accounts for about 50 percent of all plasma proteins. It gets synthesized by the liver and secreted immediately without storage. The physiological regulators of albumin are the colloid osmotic pressure and nutritional status.
- The main function of the plasma proteins that reside in the blood is to maintain proper osmotic pressure. A proper osmotic pressure needs to be maintained and since the plasma protein is mainly present in water, it forms a colloidal mixture.
- The plasma proteins suspended in blood cannot cross the semipermeable capillary cell membrane, and so they remain in the plasma within the vessel, where they account for the blood colloid osmotic pressure.