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MOVEMENTS IN AND OUT OF CELL - Coggle Diagram
MOVEMENTS IN AND OUT OF CELL
ACTIVE TRANSPORT
DEFINITION
Movement of particles from a region of low concentration to high concentration, against the concentration gradient, using energy from respiration
EXAMPLES
Uptake of ions from soil water by root hair cells in plants
root hair cell
Uptake of glucose by epithelial cells in the villi of the small intestine
villi
IMPORTANCE
Plants require mineral salts, which concentration is sometimes is higher in the plant root cell than in the soil solution, and hence the cells utilize energy to actively transport them across the cell membrance into the root cell, against the concentration gradient
PROTEIN CARRIERS
Protein carriers pick up specific molecules and take them across the cell membrance against the concentration gradient
DIFFUSION
DEFINITION
Movement of particles from a region of high concentration to low concentration ( going down concmentration gradient)
EXAMPLES
ANIMAL
Gas exchange of O2 and CO2 at alveoli in the lungs
gas exchange in lungs
PLANTS
CO2 and water vapour enters the stomata of leaf
gas exchange in plant cell
FACTOR AFFECTING RATE OF DIFFUSION
1)
Diffusion distance
--> Membranes in lungs are very thin so that oxygen and carbon dioxide can diffuse quickly
2)
Concentration gradients
--> Glucose molecules that cross the intestine is quickly removed by flowing blood so that equilibrium is not reached and the concentration gradient is maintained
3)
Surface area
--> Highly folded intestinal wall/extended root hair allows a larger surface area for diffusion to happen
4)
Temperature
--> Higher temperature, molecules have more kinetic energy and move at a higher rate (move faster)
OSMOSIS
DEFINITION
Movement of water molecules from a region of high water potential to low water potential (down a potential gradient) through a partially permeable membrane
EXAMPLES
PLANT
Water absorption by root hair cell
water absorption by root hair cell
ANIMAL
Water absorption in kidney and intestine
Water absorption in kidney and intestine
INVESTIGATION
DIALYSIS TUBING
1) Filling a section of dialysis tubing with concentrated sucrose solution.
2) Suspending the tubing in a boiling tube of water for a set period of time.
3) Noting whether the water level outside the tubing decreases as water moves into the tubing via osmosis.
EFFECT OF IMMERSING PLANT CELLS IN SOLUTIONS OF DIFFERENT CONCENTRATIONS
investigating osmosis of plant cell
TURGID CELLS
1) Outside cell has high water potential
2) Inside cell has low water potential
3) High turgor pressure as an enlarged vacuole pushes the cytoplasm towards cell wall. Inelastic cell wall ensures the plant cells do not burst.
NORMAL CELLS
1) Outside cell has equal water potential
2) Inside cell has equal water potential
3) There is no net movement of water, and so sometimes is considered flaccid
PLASMOLYSED CELL
1) Outside cell has low water potential
2) Inside cell has high water potential
3) The cytoplasm pulls away from the cell wall, and the cell becomes extremely flaccid
ROLE OF WATER
1) Digested food molecules are in the alimentary canal but need to be moved to cells all over the body (disgestion)
2) Toxic substances such as urea and substances in excess of requirements such as salts can dissolve in water (excretion)
3) Dissolved substances can be easily transported around organisms - for example, xylem and phloem of plants and dissolved food molecules in the blood (transport)
IMPORTANCE OF WATER POTENTIAL AND OSMOSIS
IN THE UPTAKE OF WATER BY ORGANISMS:
it enables water movement by osmosis from the soil to root hairs, from the tissue fluid to cells, and from xylem to leaf mesophyll cells