Transport In Vascular Plants Ch36 Campbell Apbio

Front 1

active transport

Back 1

The movement of a substance across a biological membrane against its concentration or electrochemical gradient with the help of energy input and specific transport proteins.

Hint 1

36.738

Front 2

apoplast

Back 2

In plants, the nonliving continuum formed by the extracellular pathway provided by the continuous matrix of cell walls.

Hint 2

36.743

Front 3

aquaporin

Back 3

A transport protein in the plasma membrane of a plant or animal cell that specifically facilitates the diffusion of water across the membrane (osmosis).

Hint 3

36.742

Front 4

bulk flow

Back 4

The movement of water due to a difference in pressure between two locations.

Hint 4

36.743

Front 5

Casparian strip

Back 5

A water-impermeable ring of wax around endodermal cells in plants that blocks the passive flow of water and solutes into the stele by way of cell walls.

Hint 5

36.745

Front 6

chemiosmosis

Back 6

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. Most ATP synthesis in cells occurs by _____.

Hint 6

36.740

Front 7

circadian rhythm

Back 7

A physiological cycle of about 24 hours that is present in all eukaryotic organisms and that persists even in the absence of external cues.

Hint 7

36.751

Front 8

cotransport

Back 8

The coupling of the "downhill" diffusion of one substance to the "uphill" transport of another against its own concentration gradient.

Hint 8

36.740

Front 9

endodermis

Back 9

The innermost layer of the cortex in plant roots; a cylinder one cell thick that forms the boundary between the cortex and the stele.

Hint 9

36.744

Front 10

flaccid

Back 10

Limp. Walled cells are ____in isotonic surroundings, where there is no tendency for water to enter.

Hint 10

36.741

Front 11

guttation

Back 11

The exudation of water droplets, caused by root pressure in certain plants.

Hint 11

36.746

Front 12

megapascal (MPa)

Back 12

A unit of pressure equivalent to 10 atmospheres of pressure.

Hint 12

36.740

Front 13

membrane potential

Back 13

The charge difference between the cytoplasm and extracellular fluid in all cells, due to the differential distribution of ions. ____ affects the activity of excitable cells and the transmembrane movement of all charged substances.

Hint 13

36.738

Front 14

mycorrhiza

Back 14

A mutualistic association of plant root and fungus.

Hint 14

36.744

Front 15

osmosis

Back 15

The diffusion of water across a selectively permeable membrane.

Hint 15

36.740

Front 16

passive transport

Back 16

The diffusion of a substance across a biological membrane.

Hint 16

36.738

Front 17

plasmolysis

Back 17

A phenomenon in walled cells in which the cytoplasm shrivels and the plasma membrane pulls away from the cell wall when the cell loses water to a hypertonic environment.

Hint 17

36.742

Front 18

proton pump

Back 18

An active transport mechanism in cell membranes that consumes ATP to force hydrogen ions out of a cell and, in the process, generates a membrane potential.

Hint 18

36.738

Front 19

root pressure

Back 19

The upward push of water within the stele of vascular plants, caused by active pumping of minerals into the xylem by root cells.

Hint 19

36.746

Front 20

sugar sink

Back 20

A plant organ that is a net consumer or storer of sugar. Growing roots, shoot tips, stems, and fruit are ____ supplied by phloem.

Hint 20

36.752

Front 21

sugar source

Back 21

A plant organ in which sugar is being produced by either photosynthesis or the breakdown of starch. Mature leaves are the primary ____ of plants.

Hint 21

36.752

Front 22

symplast

Back 22

In plants, the continuum of cytoplasm connected by plasmodesmata between cells.

Hint 22

36.743

Front 23

tonoplast

Back 23

A membrane that encloses the central vacuole in a plant cell, separating the cytosol from the cell sap.

Hint 23

36.743

Front 24

transfer cells

Back 24

Companion cells with numerous ingrowths of their walls which increase the cells' surface area and enhance the movement of solutes between apoplast and symplast.

Hint 24

36.752

Front 25

transpiration

Back 25

The evaporative loss of water from a plant.

Hint 25

36.746

Front 26

transport protein

Back 26

A transmembrane protein that helps a certain substance or class of closely related substances to cross the membrane.

Hint 26

36.738

Front 27

turgid

Back 27

Firm. Walled cells become turgid as a result of the entry of water from a hypotonic environment.

Hint 27

36.742

Front 28

water potential

Back 28

The physical property predicting the direction in which water will flow, governed by solute concentration and applied pressure.

Hint 28

36.740