cell functioning

activities assiciated with
the term "living" cannot
proceed without ____

water

water serves as a stabilizing factor against temperature extremes because of?

hydrogen bonds
between its molecules

when molecular bonds resist rupturing when placed under tension

cohesion

water diffuses outward

hypertonic

no net change in water movement

isotonic

water diffuses inward

hypotonic

how much heat energy is required to increase the temperature of a single gram of a substance by 1 degree Celsius

specific heat

the 3 properties of water central to cell functioning:

1) ability to stabilize temperature
2) internal cohesion
3) outstanding capacity to dissolve many substances

percentage of a cell, generally, that is water

75 to 85%

amount of heat energy that must be absorbed to convert a single gram of a liquid to a gaseous form

heat of vaporization

because of its ____, water does not chemically alter the substances dissolved in it

solvent properties

a fluid in which one or more substances can be dissolved

solvent

dissolved substances

solutes

particles in cytoplasmic water too big to dissolve and too small to settle out due to gravity

colloidal particles

two-layer film in fluids made of phospholipids with hydrophobic tails and hydrophilic heads

lipid bilayer
(the framework of all cell membranes)

____ function as a hydrophobic barrier between two fluid regions

membrane lipids

difference in the concentration
of some substance between
two regions of a defined
volume of space

concentration gradient

some substance moving along a concentration gradient until the concentration of the two areas becomes equal

diffusion

substance moves passively with the gradient

passive transport
(no direct energy needed)

substance moves
against the gradient

active transport
(requires energy outlay)

diffusion of water through a differentially permeable membrane in response to a concentration and/or pressure gradient

osmosis

plasma membrane engulfs foreign material at or near the cell surface

endocytosis

the plasma membrane surface pinches inward, extracellular fluid is surrounded and then pinched off and brought into the cell

pinocytosis ('cell-drinking')