osmosis

Question 1

definition of osmosis

Answer 1

Net movement of water molecules from a region of higher water potential to a region of lower water potential through a partially permeable membrane

Question 2

The role of water as a solvent in organisms

Answer 2

The role of water as a solvent in organisms to aid with digestion, excretion, and transport

digestion:
In animals, water helps to break down and dissolve food molecules

transport:
* substances are transported around the body dissolved in the water in blood plasma

Question 3

In animals:
Increasing solute concentration inside a cell can cause it?

Answer 3

In animals:
Increasing solute concentration inside a cell can cause it to swell and burst (lysis) because it has too much water and no cell wall

If an animal cell is placed in pure water, water enters the cell by osmosis. The cell swells and bursts.

Question 4

what happeneds If an animal cell is placed in a concentrated solution

Answer 4

If an animal cell is placed in a concentrated solution, water leaves the cell by osmosis. The cell shrinks.

Question 5

If a plant cell is placed in pure water,

Answer 5

If a plant cell is placed in pure water, water enters the cell by osmosis. The cell swells but does not burst, because of its strong cell wall.
A plant cell in this state is rather like a blown-up tyre – tight and firm. It is said to be turgid (swollen) .

Question 6

what is the turgor pressure

Answer 6

The pressure of the water pushing outwards on the cell wall is called turgor pressure.

Question 7

why is the turgor pressure important

Answer 7

Turgor pressure helps a plant to stay upright and keeps the leaves firm. Plant cells are usually turgid.

Question 8

If a plant cell is placed in a concentrated solution

Answer 8

If a plant cell is placed in a concentrated solution, water moves out of it by osmosis. The cytoplasm and vacuole shrink, so the cell becomes soft and floppy. It is said to be flaccid.
If the cells in a plant become flaccid, the plant loses its firmness and begins to wilt.

When a plant cell loses a lot of water, it also loses its turgor pressure. The contents of the cell do not push outwards on the cell wall.

Question 9

what is Plasmolysis

Answer 9

When the cell membrane tears away from the cell wall, the cell is said to be plasmolysed. Plasmolysis can kill a plant cell because the cell membrane is damaged as it tears away from the cell wall.

Question 10

what is flaccid

Answer 10

The cytoplasm and vacuole shrinks, so the cell becomes soft and floppy. It is said to be flaccid

Question 11

what is turgid

Answer 11

when water enters the cell by osmosis. The cell swells and becomes tight and firm. It is said to be turgid.