Autotrophic nutrition ( absorption of water and salts ) Flashcards
types of nutrition?
1) autotrophic nutrition
2) heterotrophic nutrition
autotrophic nutrition:
simple complex
low energy —–>. high energy
inorganic organic
heterotrophic nutrition
complex simple
high energy ——> low energy
organic inorganic
heterotrophs are classified into?
.Holozoic
.parasites
.saprophytes
Holozoic include?
.herbivores: feed on plants
.carnivores: feed on animal’s flesh
.omnivores: feed on both animals and plants
parasites such as?
.Bilharzia worms
.orobanche plant
saprophytes include?
.some fungi
.saprophytic bacteria
saprophytism:
ability of some living organisms to decompose the organic remains or the dead bodies of the living organisms
parasitism:
relation between two organisms, (parasite) depends on the other (host) by getting its food completely or partially from the host, causing different harms to the host
autotrophic nutrition in green plants is occurred through two important processes, which are:
.absorption of water and salts process
.photosynthesis process
root hair’s structure:
it is considered an extension of a single cell of (epidermis)
root hair’s length:
4mm long
root hair’s age:
few days or weeks, because the epidermis cells are teared from time to time, but they are regenerated continuously from the elongation zone of root
suitability if root hair to its function:
1) being large in number and protruding outside
2) having thin wall
3) secreting a viscous substance
4) the solution inside its sap vacuole is more concentrated than the soil solution
why are the root hair large in number and protruding outside?
to increase the surface area of water and salts absorption
why does root hair have thin wall?
to permit the passage of water and salts through it
why does root hair secrete a viscous substance?
to help these hairs to find their way easily among the soil particles and stick to them. so, they can fix the plant into the soil
why does root hair have the solution inside its sap vacuole more concentrated than the soil solution?
to help the water passage from the soil to the root ( by osmosis )
mechanism of water absorption
.diffusion phenomenon
.permeability phenomenon
.osmosis phenomenon
.imbibition phenomenon
diffusion phenomenon
it is the movement of molecules from high concentration to low concentration
permeability phenomenon
(permeable)
allow water and mineral salts to pass
EX: cellulose walls
permeability phenomenon
(impermeable)
don’t allow water and mineral salts to pass
EX: walls covered by lignin or cutin or suberin
permeability phenomenon
(semi-permeable)
(selective permeability)
-allow water to pass
-control the permeability of many salts
-prevent the permeability of sugar and amino acids, as they are large-sized molecules
EX: plasma membrane
osmosis phenomenon
it is the passage of water through the semi-permeable membranes from a medium with high concentration of water molecules ( low concentration of salts) to another one with low concentration of water molecules (high concentration of salts)
osmotic pressure
it is the pressure that causes the passage of water through semi-permeable membranes, due to the difference in concentration of dissolved substance (solutes) in water on two sides of the membrane
Imbibition
the plant cell walls absorb water through solid particles, especially the colloidal ones that have the ability to absorb water therefore they swell and increase in volume
examples of hydrophilic colloidal substance?
cellulose
pectin
protoplasmic proteins
macro nutrients
in considerable quantities
-Nitrogen (N)
-Potassium (K)
-Magnesium (Mg)
-Iron (Fe)
-Phosphorus (P)
-Calcium (Ca)
-Sulphur (S)
Macro nutrients importance?
-The nitrate, phosphate and sulphate salts work on converting the carbohydrates into proteins.
-Phosphorus enters in the formation of the energy carriers compounds (ATP).
-Iron is important for the building up of some co-enzymes which are required for the accomplishment of photosynthesis process
micro nutrients
in very small quantities
Manganese ( Mn)
Zinc (Zn)
Boron (B)
Aluminium (Al)
Chlorine (Cl)
Copper (Cu)
Molybdenum (Mo)
Iodine ( I )
Micro nutrients importance?
some of these elements work as activators for enzymes
mechanism of mineral salts absorption
-diffusion phenomenon
-selective permeability phenomenon
-active transport phenomenon
diffusion phenomenon ( salts absorption )
solutes move by diffusion from the soil solution (high-concentrated medium) and passthrough the cellulose walls (low-concentrated medium), due to the continuous movement of free ions.
under certain conditions, cations exchange may take place through the cell membrane
selective permeability phenomenon (salts absorption)
ions reach the semi-permeable membrane, some of them are selected and allowed inside the cell to pass through it, while other ions aren’t allowed, according to the plant need, regardless of their size, concentration or charge.
active transport phenomenon (salts absorption)
(ions diffuse from low concentration to high concentration) and the passage of any substance through the cell membrane, when it needs chemical energy
active transport phenomenon (salts absorption)
ions diffuse from the soil solution (low concentration) to inside the cell (high concentration), the presence of chemical energy is needed to force these ions to move against this concentration gradient
