Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
35 Cards in this Set
- Front
- Back
Apoplast
|
In plants, the continuum of cell walls plus the extracellular spaces.
|
|
Bulk Flow
|
The movement of water due to a difference in pressure between two locations.
|
|
Casparian Strip
|
A water-impermeable ring of wax in the endodermal cells of plants that blocks the passive flow of water and solutes into the stele by way of cell walls.
|
|
Chemiosmosis
|
An energy-coupling mechanism that uses energy stored in the form of a hydrogen ion gradient across a membrane to drive cellular work, such as the synthesis of ATP.
|
|
Circadian Rhythms
|
A physiological cycle of about 24 hours that is present in all eukaryotic organisms and that persists even in the absence of external cues.
|
|
Cohesion
|
The binding together of like molecules, often by hydrogen bonds.
|
|
Endodermis
|
The innermost layer of the cortex in plant roots, a cylinder one cell thick that forms the boundary between the cortex and the vascular cylinder.
|
|
Essential Nutrient
|
A substance that an organism must absrb in preassembled form because it cannot be synthesized from any other mineral.
|
|
Guttation
|
The exudation of water droplets, caused by root pressue in certain plants.
|
|
Horizons
|
A distinct layer of soil, such as topsoil.
|
|
Humus
|
Decomposing organic material found in topsoil.
|
|
Loam
|
The most fertile of all soils, made up of roughly equal amounts of sand silt, and clay.
|
|
Macronutrients
|
A chemical substance that an organism must obtain in relatively large amounts.
|
|
Micronutrient
|
An element that an organism needs in very small amounst and that functions as a component or cofactor of enzymes.
|
|
Mineral Nutrients
|
An essential chemical element absorbed from soil in the form of inorganic ions.
|
|
Mycorrhizae
|
Mutualistic associations of plant roots and fungi.
|
|
Nitrogen Fixation
|
The assimilation of atmospheric nitrogen by certain prokaryotes into nitrogenous compounds that can be directly used by plants.
|
|
Nitrogenase
|
An enzyme complex, unique to certain prokaryotes, that reduces nitrogen to NH3.
|
|
Nitrogen-Fixing Bacteria
|
Microorganisms that restock nitrogenous minerals in the soils by converting nitrogen to ammonia.
|
|
Nodules
|
A swelling on the root of a legume. Are composed of plant cells that contain nitrogen-fixing bacteria of the genus Rhizobium.
|
|
Osmosis
|
The diffusion of water across a selectively permeable membrane.
|
|
Plasmolyze
|
To shrink and pull away from a cell wall, or when a plant cell protoplast pulls away from the cell wall as a result of water lose.
|
|
Root Pressure
|
The upward push of xylem sap in the vascular tissue of roots.
|
|
Selective Channels
|
Channels that only allow certain molecules to pass through.
|
|
Sugar Sink
|
A plant organ that is a net consumer or storer of sugar. Growing roots, shoot tips, stems, and fruits are these that are supplied by the phloem.
|
|
Sugar Source
|
A plant organ in which sugar is being produced by either photosynthesis of the breakdown of starch.
|
|
Symplast
|
In plants, the continuum of cytoplasm connected by plasmodesmata between cells.
|
|
Tonoplast
|
A membrane that encloses the central vacuole in a plant cell, separating the cytosol from the vacuole contents, called cell sap.
|
|
Topsoil
|
A mixture of particles derived from rock, living organisms, and humus.
|
|
Transfer Cells
|
A companion cell with numerous ingrowths of its wall, increasing the cell's suface area and enhancing the transfer of solutes between apoplast and symplast.
|
|
Translocation
|
The transport of organic nutrients in the phloem of vacular plants.
|
|
Transport Proteins
|
A transmembrane protein that helps a certain substance or class of closely related substances to cross the membrane.
|
|
Turgid
|
When a cell wall becomes very firm when it has a greater solute concentration than its surroundings, resulying in entry of water.
|
|
Turgor Pressure
|
The force directed against a cell wall after the influx of water and the swelling of a walled cell due to osmosis.
|
|
Water Potential
|
The physical property predicting the direction in which water will flow, governed by solute concentration and applied pressure.
|