Topic 1 - Envi Sci

Environmental Science

The systematic study of our environment and our proper place in it; integrates natural and social sciences.

Environmental Engineering

A branch of engineering that improves environmental quality and protects people from pollution.

Ecology

The scientific study of relationships between organisms and their environment.

Matter

Everything that takes up space and has mass; exists in solid, liquid, gas, or plasma states.

Conservation of Matter

Matter is neither created nor destroyed; it is continuously recycled in ecosystems.

Elements

Substances that cannot be broken down by ordinary chemical reactions; 92 are natural, 30 are artificial.

Four Main Elements in Living Organisms

Oxygen, Carbon, Hydrogen, and Nitrogen.

Atoms

Smallest particles that exhibit the characteristics of an element; composed of protons, neutrons, and electrons.

Ions

Atoms that have gained or lost electrons, acquiring an electrical charge.

Anions

Negatively charged ions; example: Clâ».

Cations

Positively charged ions; example: Hâº.

Acids

Substances that readily give up hydrogen ions in water.

Bases

Substances that readily bond with hydrogen ions.

pH

A scale that measures the strength of acids and bases.

Organic Compounds

Carbon-based compounds that form the foundation of living organisms.

Four Major Organic Compounds

Lipids, Carbohydrates, Proteins, and Nucleic Acids.

Nucleic Acids

Complex organic molecules (DNA and RNA) that store and express genetic information.

Cells

Minute compartments where life processes occur; the basic unit of life.

Enzymes

Proteins that act as catalysts to regulate chemical reactions without being used up.

Metabolism

All the enzymatic reactions performed by an organism.

Energy

The ability to do work or cause change; measured in joules or calories.

Kinetic Energy

Energy contained in moving objects.

Potential Energy

Stored energy available for use.

Chemical Energy

Energy stored in bonds of chemical substances like food or fuel.

Heat

Energy transferred between objects of different temperatures.

First Law of Thermodynamics

Energy cannot be created or destroyed, only transformed.

Second Law of Thermodynamics

With each energy transfer, some energy becomes less useful (entropy increases).

Chemosynthesis

Process where bacteria use chemical bonds of inorganic elements for energy.

Photosynthesis

Process where green plants convert solar energy into chemical energy.

Producers

Organisms that make their own food through photosynthesis; mainly plants and algae.

Consumers

Organisms that obtain energy by eating other organisms.

Herbivores

Plant-eating animals such as cows and goats.

Carnivores

Meat-eating animals such as lions and wolves.

Omnivores

Organisms that eat both plants and animals, such as humans.

Scavengers

Animals that consume dead carcasses, e.g., vultures.

Decomposers

Organisms like fungi and bacteria that break down dead material and recycle nutrients.

Trophic Level

An organism’s feeding position in an ecosystem.

Food Chain

A linear series showing who eats whom in an ecosystem.

Food Web

A network of interconnected food chains.

Ecological Pyramid

Graphical representation of relationships between organisms in trophic levels.

Pyramid of Numbers

Shows the number of organisms in each trophic level.

Pyramid of Biomass

Shows the total mass of organisms at each trophic level.

Pyramid of Productivity

Shows the flow of energy at each trophic level over time.

Water Cycle

Cycle that distributes water among atmosphere, land, and oceans.

Evaporation

Process where water changes from liquid to vapor due to heat.

Transpiration

Release of water vapor from plant leaves.

Condensation

Process where vapor cools and turns back into liquid.

Precipitation

Water falling from clouds as rain, snow, or hail.

Runoff

Water flow over land into bodies of water.

Percolation

Movement of water through soil into groundwater.

Carbon Cycle

Cycle describing movement of carbon through photosynthesis, respiration, and decomposition.

Nitrogen Cycle

Cycle where nitrogen moves through atmosphere, soil, and living organisms.

Phosphorus Cycle

Cycle where phosphorus moves through rocks, water, and organisms; no atmospheric form.

Primary Productivity

Rate of biomass production by photosynthetic organisms.

Secondary Productivity

Biomass produced by consumers eating plants.

Population

Members of a species living in a given area at one time.

Community

All populations living and interacting in a particular area.

Ecosystem

A community and its physical environment interacting together.

Abiotic Factors

Non-living components like sunlight, water, and minerals.

Biotic Factors

Living components such as plants, animals, and microorganisms.