Movement In And Out Of Cells

Front 1

Diffusion

Back 1

Net movement ofmolecules from a region of their higherconcentration to a region of their lowerconcentration down a concentration gradient, asa result of their random movement.

Front 2

Describe the importance of diffusion of gases

Back 2

Necessary for gas exchange in all living organisms

Necessary for obtaining Carbon Dioxide and releasing oxygen during photosynthesis.

Front 3

Active Transport

Back 3

As movement of ionsin or out of a cell through the cell membrane,from a region of their lower concentration to aregion of their higher concentration against aconcentration gradient, using energy releasedduring respiration

Front 4

Types of active transport

Back 4

Front 5

Osmosis

Back 5

As the diffusion of watermolecules from a region of their higherconcentration (dilute solution) to a region of theirlower concentration (concentrated solution),through a partially permeable membrane

Front 6

Describe the importance of osmosis in theuptake of water by plants, and its effects onplant and animal tissues

Back 6

-Plants gain water through osmosis in their roots from the soil.

-Without a water potential gradient,water will be loss from the roots .

-Plant cells contain vacuoles, which, if not full with water, will cause the cell to become flaccid. If all the cells in a leaf become flaccid, the whole leaf will become flaccid, hence causing the plant to wilt.

-Plant cells therefore need water to remain turgid and keep firm.If an animal cell surrounded with a high water potential, osmosis will take place, and if the water is not expelled some way or another, the cell will burst.

-This is because an animal cell doesn’t have a cell wall to keep it strong.

-If an animal cell is surrounded with low water potential, the water in the cytoplasm will diffuse outwards, causing the cell to shrink.

Front 7

Describe and explain the importance of awater potential gradient in the uptake of waterby plants

Back 7

-The water potential determines whether the plant cell would be turgid or plasmolysed.

-If the surroundings has a higher water potential than the plant cell, water molecules moves into the plant cell via osmosis.

-When the plant cell has sufficient water, it becomes turgid.

-The cell wall prevents the cell from bursting.

-Turgor pressure is exerted when the plant cell is swollen. This keeps the plant upright.

Front 8

Isotonic solution

Back 8

Concentration of solute outside cell equals concentration inside cell -> No change

Front 9

Hypertonic solution

Back 9

Concentration of solute outside cell is more than concentration inside cell -> Cell shrinks

Front 10

Hypotonic solution

Back 10

Concentration of solute outside cell is less than concentration inside cell -> Cell swells

Front 11

Describe the importance of diffusion of solutes

Back 11

Dissolved salts dissolve through root hair cell.

Absorption of dissolved food material in many organisms, like amoeba, bacteria and fungi is carried out through diffusion.

Some digested food material is absorbed by diffusion.

Front 12

Describe the importance of diffusion of water as a solvent

Back 12

Plants cannot obtain minerals unless they are dissolved in water.

Enzymes and hormones cannot be secreted unless they are dissolved in water.

Excretory products cannot be excreted unless they are dissolved in water.