Table of Contents
- 1 Where water and dissolved substances move through a membrane in response to pressure is referred to as?
- 2 What is the diffusion of water and dissolved materials across a membrane down a pressure gradient?
- 3 What are two things through which water moves?
- 4 What are the three factors that affect diffusion?
- 5 How is water transported across a semi permeable membrane?
- 6 How are molecules transported across the plasma membrane?
Where water and dissolved substances move through a membrane in response to pressure is referred to as?
Osmosis is the diffusion of water molecules across a semi‐permeable membrane. When water moves into a cell by osmosis, hydrostatic pressure (osmotic pressure) may build up inside the cell.
What is the movement of water from an area of high concentration called?
Osmosis
Key terms
| Term | Meaning |
|---|---|
| Osmosis | The net movement of water across a semipermeable membrane from an area of lower solute concentration to an area of higher solute concentration |
| Tonicity | The ability of an extracellular solution to make water move into or out of a cell by osmosis |
What is the diffusion of water and dissolved materials across a membrane down a pressure gradient?
Osmosis Osmosis is the diffusion of water through a semipermeable membrane down its concentration gradient. If a membrane is permeable to water, though not to a solute, water will equalize its own concentration by diffusing to the side of lower water concentration (and thus the side of higher solute concentration).
What is the correct path of movement of water?
Thus, the water absorbed through root hairs enters into the root that moves horizontally through the cortex, endodermis, and pericycle before reaching the xylem. Therefore, the correct path of movement of water from the soil to the xylem is: Soil→root hair→cortex→endodermis→pericycle→protoxylem→metaxylem.
What are two things through which water moves?
When it rains, water falling onto the ground can move in two ways – it can run off the surface of the ground and enter streams and rivers, or it can seep into the ground and enter the ground water. This second process is called infiltration – water moves through pore spaces between soil particles or rocks.
What are the factors that affect diffusion rate?
The rate of diffusion
| Factor | Reason |
|---|---|
| The temperature | The higher the temperature, the more kinetic energy the particles will have, so they will move and mix more quickly. |
| The surface area of the cell membrane separating the different regions | The greater the surface area, the faster the rate of diffusion. |
What are the three factors that affect diffusion?
Several factors affect the rate of diffusion of a solute including the mass of the solute, the temperature of the environment, the solvent density, and the distance traveled.
How does water move from higher concentration to lower concentration in osmosis?
Osmosis: In osmosis, water always moves from an area of higher water concentration to one of lower concentration. In the diagram shown, the solute cannot pass through the selectively permeable membrane, but the water can. Returning to the beaker example, recall that it has a mixture of solutes on either side of the membrane.
How is water transported across a semi permeable membrane?
Semipermeable membranes, also termed selectively permeable membranes or partially permeable membranes, allow certain molecules or ions to pass through by diffusion. While diffusion transports materials across membranes and within cells, osmosis transports only water across a membrane.
Why are there different amounts of water on both sides of the membrane?
If the volume of the solution on both sides of the membrane is the same but the concentrations of solute are different, then there are different amounts of water, the solvent, on either side of the membrane. If there is more solute in one area, then there is less water; if there is less solute in one area, then there must be more water.
How are molecules transported across the plasma membrane?
Facilitated diffusion is a process by which molecules are transported across the plasma membrane with the help of membrane proteins. A concentration gradient exists that would allow ions and polar molecules to diffuse into the cell, but these materials are repelled by the hydrophobic parts of the cell membrane.