1. How/why do cells maintain homeostasis?
Because the cells must be in a stable state. The need homeostasis to be able to function normally.
2. Define selectively permeable membrane.
The cell membrane only allows specified molecules to pass by. And it blocks all the other molecules.
3. Describe the difference between active and passive transport of substances across cell membranes.
ATP is required to function in Active Transport, which the molecules go from a low to high concentration gradient. ATP is not required in Passive Transport, which the ¬molecules go from a high to low concentration gradient.
4. Define diffusion. Describe how diffusion works. Is diffusion active or passive?
Diffusion is a process in which molecules move from a high concentration to a low concentration. It works by the water and selected solutes moving from cell to cell using the kinetic energy of the atoms. Diffusion is passive.
5. Define osmosis. Describe osmosis works. Is osmosis active or passive?
Osmosis is a process in which the molecules go from a low concentration to a high concentration. It works by the concentration of water and the equilibrium of the substances involved in the solutions. Osmosis is passive.
6. What is meant by “osmotically active substance”?
It is a substance that is prone to make osmosis take place. It is a type of substance that can’t freely move into/out of a cell membrane.
7. Define hypertonic, hypotonic, and isotonic. If a cell is placed in each of these solutions, what will be the direction of water movement? (into the cell, out of the cell, or no net change)
Hypertonic means that there is greater concentration outside than inside. Hypotonic means that there is lower concentration outside than inside. Isotonic means that there is equal concentration inside and outside. If the cell is placed in a hypertonic solution, the water will move out of the cell. If the cell is placed in a hypotonic solution, the water will move into the...