Water Quality Vocab

Chloroplasts

Only found in eukaryotic cells such as plants and algae. Carbon dioxide, water, and light energy make glucose and molecular oxygen during photosynthesis.

Autotroph

An organism that can produce its own food.

Photoautotroph

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

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.

Chlorophyll

A pigment (a molecule that absorbs light) through which the entire process of photosynthesis begins.

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

Oxygen

Carbon Dioxide

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

Surface Runoff

The flow of freshwater over land either from rain or melting ice. Runoff can make its way through streams and lakes to the oceans.

Watershed

The geographic area drained by a river and its tributaries.

Transpiration

water loss by plants to the atmosphere

Water stress

Water shortages

Desalination

removing dissolved salt from seawater or saline groundwater

Dissolved oxygen

Aquatic organisms need for cellular respiration. Bacteria decompose dead organic matter and remove dissolved oxygen (O₂) according to the following reaction: organic matter + O_2→CO₂ + H₂O

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