C8: Mineral Nutrition (Pt 2) Flashcards
___ – cells in leaves that control opening & closing of leaf pores (stoma).
Guard cells
is the layer of cells inside a plant’s stem that divides to make new cells.
cambium
System of hollow ‘pipes’ inside a plant that allow the transport of water and the dissolved
nutrients inside the plant.
Xylem tissue
these cells are dead–they start off alive, then get very thick cell walls then die, leaving
them hollow
Xylem cells
the system of pipes inside a plant that allows transport of sugars (the sap) and
plant hormones.
phloem
xylem is responsible for moving water and minerals ___from the roots, phloem is ___.
upward;
downward
Nutrient Acquisition Processes (3)
Absorption by Roots
Osmosis and Diffusion
Ion Exchange in Soil
___, carrying dissolved nutrients, moves into the plant, providing the medium
for transporting these nutrients.
Water
roots release ___into the soil, which helps to dislodge
nutrient ions attached to soil particles.
hydrogen ions
– also known as negative pressure or suction, is a force that pulls water up a plant through
the xylem.
Tension
is the process of water evaporating out of the xylem via the stomata.
Transpiration
causes the tension/suction to make water go up from roots to leaves.
Transpiration
– the property of water molecules sticking to each other.
Cohesion
when water evaporates out of the
stomata in the leaves, it draws more water up because the water molecules are all clinging to each
other. This is called ___of the water column.
cohesiveness
Pressure in a plant is created through a sugar concentration gradient, which allows the flow of
sap.
Pressure-Flow Hypothesis
Nutrients move to the roots via three methods
Root extension
Mass Flow
Diffusion
– exposure to soil and new supplies of nutrients roots could contact 3% of
the soil or nutrients in the soil
Root extension
– water absorbed by the root creates a water deficit near the root in the soil;
then more water moves near to the root carrying nutrients with the water. This is an
important point for nutrients in large quantities in the soil solution, like N, K & Ca.
Mass Flow
– movement of nutrients due to an imbalance of concentration (diffusion
gradient).
Diffusion
Conditions for nutrient uptake(4)
-Actively growing
-Metabolic energy (able to respire; have oxygen; consider porosity)
-root hairs
-selective process
Nutrient Assimilation Processes (3)
Nitrate Reduction and Ammonium Assimilation;
Photosynthesis and Carbon Assimilation;
Protein and Enzyme Formation
– in roots and leaves, nitrate (NO₃⁻) is
converted to ammonium (NH₄⁺), which plants can incorporate into amino acids.
Nitrate Reduction and Ammonium Assimilation
