Movement of Substances Across a Plasma Membrane in Living Organisms

3.3

Movement of Substances Across a Plasma Membrane in Living Organisms

Active and passive transport in living organisms:

Passive transport	Active transport
gaseous exchange between an alveolus and a blood capillary through simple diffusion. reabsorption of water occurs by osmosis through the renal tubule in the kidney. absorption of water by a plant root hair cell by osmosis. absorption of fructose molecule in the villus by facilitated diffusion.	absorption of glucose and amino acids in the villus. reabsorption of glucose through the renal tubule in the kidney. transport of sucrose from a leaf to a phloem tissue. absorption of mineral ions by a plant root hair cell.

Hypertonic,hypotonic and isotonic solutions:

Solution	Description
Hypertonic	A solution that has high concentration of solute
Hypotonic	A solution that has low concentration of solute
Isotonic	A solution that has the same concentration of solute with the water potential

The effects of hypotonic, hypertonic and isotonic solutions on animal cells and plant cells:

Animal cell	Condition	Plant cell
Hemolysis	Hypotonic A solution that has low concentration of solute than water in a cell; causing the water to diffuse in	Turgid
Crenation	Hypertonic A solution that has high concentration of solute than water in a cell; causing the water to diffuse out	Plasmolysis and flaccid
Maintain its shape	Isotonic A solution that has the same concentration of solute with the water potential in a cell; not net movement of substance	Maintain its shape