Untitled Flashcards Set

Nutrients(a chemical in food, used for energy, growth, body building, or cell repair) or organic: Carbohydrate (an organic nutrient made of carbon, hydrogen, and oxygen), Protein( an organic nutrient composed of a chain of amino acids), lipid (an organic nutrient that does not dissolve in water), Vitamin (a molecule that helps enzymes function in the body)

Inorganic substances that are not destroyed by cooking or exposure to air are referred to as minerals. Mineral requirements are distinguished by the amount needed: macromineral(100 mg/day or more) or trace element(less than 100 mg/day). These minerals are essential components in enzymes(special protein molecules that regulate chemical reactions in living organisms)

Pesticide a chemical used to control "pests" : herbicide a chemical used to control weeds, insecticide a chemical used to control insects, fungicide a chemical used to control moulds and fungi.

LD50 the dose of a chemical that will kill 50% of the population to which it is applied

Biomagnification the process whereby chemicals accumulate in the tissues of organisms along the food chain.

Bioaccumulate to collect in progressively higher concentrations toward the top of the food chain

biological indicator a living organism whose state is indicative of conditions in a particular environment

Acid  a chemical that produces an acidic substance, having a pH value of less than 7

Acid precipitation rain or snow containing acid compounds from the air

Acid rain rain that contains higher than normal levels of acid; caused by waste gases released into the atmosphere by industries and automobiles; damaging to the environment

Acid-base neutralization the combining of an acid and a base to produce salt and water

base: a chemical that produces a basic substance, having a pH value of more than 7 

basic having a pH value of more than 7

indicator a chemical that changes colour to indicate whether a substance is an acid or a base

liming the process of adding calcium carbonate to the environment

litmus a mixture of plant compounds used as a chemical indicator

pH scale a scale that measures the acidity or alkalinity of a substance

pH paper paper saturated with a chemical to show whether a substance is acidic or basic

catalytic converter a device that encourages complete oxidation during combustion

A catalyst is a substance that speeds up a chemical reaction without being used up in the reaction. 

oxidation a chemical reaction in which oxygen combines with other elements to form new substances

scrubbers antipollution systems that remove sulfur dioxide and contaminating gasses resulting from the burning of fossil fuels

sorbent a substance that absorbs oxides

An acceptable risk is a level of danger and harm that people tolerate because the benefits outweigh the downsides

In general, a pollutant is any material, or form of energy, that will cause harm to a living organism. The harm may be the result of physical, chemical, or even biological mechanisms that threaten the health or survival of that organism. Pollution is any alteration of the environment producing a condition that is harmful to living things.

macroinvertebrates— organisms visible to the unaided eye and lacking a backbone.

non-persistent wastes wastes that can be broken down into simple nonpolluting compounds by naturally occurring chemical reactions or bacterial action

 non-point source a source of pollution in which pollutants are diffuse and originate from no specific location

Toxicityis the ability of a chemical to cause harm to an organism. The harm can either occur directly or be caused by the substances that form in the organism as it uses that chemical. A chemical has acute toxicity when serious symptoms occur after only one exposure to the chemical. Methyl isocyanate is one such chemical. Chronic toxicityis diagnosed when symptoms appear only after a chemical accumulates to a specific level after many exposures over time. Lead is an example of this type of substance. For both acute and chronic toxicity, exposure to a chemical is critical.

persistent wastes wastes that accumulate in the environment and break down very slowly, if at all

point source a specific location where pollution originates

ground water water that filters down through soil and fills spaces in the ground

Aquifer an underwater reserve of water

Biodegradable substances are those organic compounds (natural or synthetic) that can be broken down by bacteria, fungi, and other simple organisms into carbon dioxide and water.

A hazardous waste is any discarded material that contains substances that are known to be poisonous, toxic, corrosive, flammable, or explosive.

A solvent is any substance that can be used to dissolve another substance.

sanitary landfill a landfill incorporating a waterproof liner filled with compacted garbage covered

leachate the liquid that results as wastes decompose and rainwater filters down through the landfill

 Secure landfill a specialized landfill that safely disposes of hazardous and toxic wastes

bioreactor a tank containing bacteria in appropriate conditions for bioremediation to occur bioremediation a method of using living organisms to break down complex, toxic substances into simpler, non-toxic ones