ch 3 aquatic environments

Viscosity

the thickness of a fluid that causes objects to encounter resistance as they move through it

ions

atoms or groups of atoms that carry an electric charge

Saturation

The upper limit of solubility in water

Acidity

the concentration of hydrogen ions in a solution

pH

a measure of acidity or alkalinity

Acid deposition

acids deposited as rain and snow or as gases and particles that attach to the surface of plants, soil, and water. Also known as acid rain

Solutes

a dissolved substance

Osmosis

the movement of water across a semipermeable membrane

osmotic potential

the force with which an aqueous solution attracts water by osmosis

Semipermeable membrane

a membrane that allows only particular molecules to pass through

Passive transport

the movement of ions and small molecules through a membrane along a concentration gradient, from a location with many solutes to a location with fewer solutes

Active transport

the movement of molecules or ions through a membrane against a concentration gradient

osmoregulation

the mechanisms that organisms use to maintain proper solute balance

hyperosmotic

when an organism has a higher solute concentration in its tissues than the surrounding water

hyposmotic

when an organism has a lower solute concentration in its tissues than the surrounding water

Freshwater salinization

the increased concentration of salt in rivers, streams, lakes, and wetlands

Sample standard deviation

a statistic that provides a standardized way of measuring how widely data are spread from the mean

Standard error of the mean

a measurement of variation in data that takes into account the number of replicates that were used to measure the standard deviation

Bicarbonate ions

an anion formed by the dissociation of carbonic acid

Carbonate ion

an anion formed by the dissociation of carbonic acid

boundary layer

a region of unstirred air or water that surrounds the surface of an object

Countercurrent circulation

movement of two fluids in opposite directions on either side of a barrier through which heat or dissolved substances are exchanged

Concurrent circulation

movement of two fluids in the same direction on either side of a barrier through which heat or dissolved substances are exchanged

Anaerobic/ anoxic

without oxygen

Thermoregulation

the ability of an organism to control the temperature of its body

Homeotherms

an organism that maintains constant temperature conditions within its cells

Homeostasis

maintaining a constant internal environment

Poikilotherms

an organism that does not have constant body temperatures

Heterotherm

an organism that sometimes maintains a relatively constant body temperature and at other times has a body temperature that is a product of the surrounding environmental temperature

Ectotherm

an organism with a body temperature that is largely determined by its external environment

Endotherm

an organism that can generate sufficient metabolic heat to raise its body temperature higher than the external environment

Thermal optimum

the temperatures at which organisms perform the best

Thermophilic

heat-loving

Thermal pollution

discharging water that is too hot to sustain aquatic species

Glycerol

a chemical that prevents the hydrogen bonds of water from coming together to form ice unless the temperatures are well below freezing

Glycoproteins

a group of compounds that can be used to lower the freezing temperature of water

Supercooling

a process in which glycoproteins in the blood impede ice formation by coating any ice crystals that begin to form

Coral bleaching

loss of color in corals as a result of the corals expelling their symbiotic algae

Ocean acidification

a decline in ocean pH associated with increased concentrations of carbon dioxide