Water Quality Vocab

Watershed

The geographic area drained by a river and its tributaries

Transpiration

the process where plants absorb water through their roots and release the water vapor through tiny pores in their leaves

Water stress

the global situation involving water shortages

Desalination

removing dissolved salt from seawater or saline groundwater

Dissolved oxygen

The amount of free, non compounded oxygen molecules present in water or other liquids that is available for aquatic life to breathe

Biochemical oxygen demand

The amount of oxygen used by aerobic (in the presence of oxygen) bacterial decomposition of organic matter

Water residence time

the average time a water molecule spends in a water reservoir

Surface runoff

the flow of freshwater over land either from rain or melting ice

Chloroplasts

are a particularly important type of organelle because they perform photosynthesis

Autotroph

is an organism that can produce its own food

Photoautotrophs

a type of autotroph that uses sunlight and carbon from carbon dioxide to synthesize chemical energy in the form of carbohydrates

Heterotrophs

organisms incapable of photosynthesis that must obtain energy and carbon from food by consuming other organisms.

Photosynthesis

requires sunlight, carbon dioxide, and water as starting reactants. After the process is complete, photosynthesis releases oxygen and produces carbohydrate molecules, most commonly glucose. These sugar molecules contain the energy that living things need to survive.

Chlorophyll

Embedded in the thylakoid membrane are molecules of chlorophyll, a pigment (a molecule that absorbs light) through which the entire process of photosynthesis begins.

Oxygen

The light-dependent reactions release oxygen as a byproduct of the splitting of water.

Carbon dioxide

chemical energy derived from the light-dependent reactions drives carbon capture in carbon dioxide molecules and the subsequent assembly of sugar molecules.