Environmental Chemistry Visual Dictionary

Nutrient: elements and compounds that organisms need for living, growing and reproducing

Enzyme: catalyst involved in chemical reactions in living things.

Organic compounds: compounds whose molecules contain CARBON (for example fossil fuels or glucose). [exceptions: carbon dioxide, carbon monoxide, carbonates, and cyanides which are inorganic].   Glucose molecule

Inorganic compounds: compounds whose molecules DO NOT contain carbon Inorganic compounds: compounds whose molecules DO NOT contain carbon. Also included as inorganic compounds are carbon dioxide, carbon monoxide, carbonates and cyanides. Copper nickel sulphate nitrate

Protein: organic compound made up of units called amino acids; protein molecules contain atoms of nitrogen, hydrogen, oxygen and carbon.

Lipid : organic molecules made up of atoms of carbon, hydrogen, and oxygen (example, fats, oils and waxes). Lipids are not soluble in water.

Carbohydrate: organic molecules made up of atoms of carbon, hydrogen, and oxygen ( example pasta, rice, potatoes, fruits and breads) ; can form simple molecules such as sugar, or large complex molecules such as starch, cellulose and glycogen.

Macromineral: nutrients that organisms need in relatively large amounts.

Trace element: nutrients that are essential for plant and animal growth and development, but are only needed in very small amounts. Also called microminerals. Ex. Selenium.

Vitamin: Any of a group of organic compounds that are essential for normal growth and nutrition and are required in small quantities in the diet.

biological magnification: increase in concentration of a chemical or element as it moves up the food chain.

Herbicide: chemical used to kill or control weeds.

Fungicide: chemical used to kill fungi.

Pesticide: chemical used to kill pests Pesticide: chemical used to kill pests. Pests are organisms that harm people, crops or structures.

Acid: compound that dissolves in water to form a solution with a pH lower than 7. Ex. Sulphuric acid, formic acid, nitric acid

Base: compound that dissolves in water to form a solution with a pH higher than 7. Ex. Baking soda, soap, lye, toothpaste.

acid precipitation (acid rain): precipitation with a pH lower than 5 acid precipitation (acid rain): precipitation with a pH lower than 5.6 is considered acid rain.

Indicator: to identify a substance as an acid or base or neutral, an indicator is used ( litmus paper, phenol red for example).

pH scale: a measure of the percent of hydrogen ions in a solution; most solutions have a pH in the range of 0 to 14. 0 is very acidic, 14 is very basic, and 7 is neutral.  

Acid-Base neutralization: when an acid and a base combine, the products are a salt and water.  

leachate: water that passes through soil and carries dissolved substances with it.

Heavy metal: metals that have a density of 5 or higher ( copper, zinc, lead, mercury, cadmium, nickel); heavy metals are one type of substance monitored to determine water quality.  

pollution: any change in the environment that produces a condition that is harmful to living things.   

Toxicity: how poisonous a substance is. acute toxicity: toxicity that is harmful after one exposure.   chronic toxicity: toxicity that is harmful after long term exposure.  

LD50: lethal dose 50; amount of a substance that causes 50% of a group of test animals to die if they are given a specified dose of the substance all at once.

Biological indicator: example – monitoring the number of crayfish in a lake. If the population starts to decrease, it is an indicator that the lake is being poisoned. Scientists use organisms that live in water to help determine water quality.