Environmental Chemistry Part One Flashcards
Why is nitrogen important?
It is required by plants to make substances necessary to life.
How can Nitrates be added?
- nitrogen fixing plants (clovers, beans, alfalfa)
- fertilizers/ compost/ manure
- lightning
How can Nitrates be taken away?
- bacteria that convert soil into free N2
- water carries away nitrates
- harvesting plants
What are the natural processes?
Chemical cycles- cycling of elements and compounds through the environment (water)
Cellular respiration- food chemicals and oxygen are used to provide the body with energy, carbon dioxide is produced.
What are Human Activities?
Pollution- any change in the environment that produces conditions harmful to living things (smog and forest fires.)
Agricultural Activities- farmers use chemicals to help control the growth of their crops
Examples of Agricultural Activities?
Fertilizers- chemicals added to the soil to increase plant growth (different ratios of nitrogen, phosphorus, and potassium used to produce different things)
Crop Rotation- crops that are nitrogen fixing increases soil nitrates
Pesticides- chemicals used to kill pests (herbicides=weeds; insecticides=insects’ fungicides-fungus)
Problems of Pesticides?
- not selective and kills pests and non-pests
- some remain in the environment and can be passed onto other organisms
- pests can become resistant to them
What are organic foods?
Foods grown in an environment free of pesticides
What are more Human Activities? 2
Solid wastes- garbage that cannot be recycles is put into land fills lined with plastic and clay.
wastewater/sewage- water with dissolved/undissolved materials is carried by pipes to a septic tank and to water treatment plants
How is sewage treated?
septic tanks- Underground containers where bacteria breakdown organic materials before they are moved out into the soil
Sewage treatment plant- treats wastewater and releases (effluent) into rivers and lakes. Often have nitrogen and phosphorus.
Storm Sewers- large areas used to collect street water before released into rivers and lakes. Contains chemical from the street.
What are more Human activities? 3
Fuel Combustion- oxygen is used to burn fossil fuels and energy (H2O and CO2) is released
Industrial Processes- power generation, mineral processing, fertilizer production, etc
What are fossil fuels? Natural gases?
Fossil Fuels- Fuels formed from dead plants and animals. (coal, oil, natural gas)
Natural gas-Composed of various compounds that can be seperated and used.
What is pH?
A measure of the concentration of hydrogen ions in solutions.
Traits of Acids?
- taste sour
- soluble in water
- corrosive
- conduct electricity
- react with metals
- most formulas start with H
Traits of Bases?
- taste bitter
- soluble in water
- feel slippery
- corrosive
- conduct electricity
- react with acids
- found in soaps, detergents
- end in OH
What are acids? Bases?
Acid- a compound that dissolves in water to form a solution with a pH lower than 7
Base- a compound that dissolves in water to form a solution with a pH higher than 7
What is Neutral ?
A pH of 7.
What is a universal indicator?
shows a wide variety of colors, each indicating a different pH when compared to a color chart
What is neutralization?
A reaction where an acid and base come together to produce water and a salt.
What is a neutralization reaction?
A reaction between an acid and a base where water (HOH) and salt are formed.
What are buffers ?
A substance that can neutralize either an acid or a base.
What is CHON?
Carbon
Hydrogen
Oxygen
Nitrogen
What are organic and inorganic materials?
Organic- molecules with carbon
Inorganic- molecules without carbon
What are nutrients?
elements and compounds needed for living, growing, reproducing
What are macro nutrients?
9 elements needed in large amounts- CHON, phosphorus, potassium, magnesium, calcium, sulfur
What are micro nutrients?
Elements need only in trace amounts (ex. iron, selenium)
What are optimum amounts?
The right amount of nutrients
What are carbohydrate molecules?
They are made up of CHO.
- found in foods like pasta, potatoes, rice
What are the two categories of carbohydrates?
Simple sugars- one or two sub units long (ex. glucose from photosynthesis)
Complex carbohydrates- long repeating chains of glucose joined together. (ex. starch, glycogen)
What are lipids?
Made up of CHO atoms
- produced by plants and animals (fats, waxes, oils)
What are proteins?
- made up of CHON
- used for growth, repair, energy source
- made of amino acids (each has own number and arrangement)
What are enzymes?
Specialized proteins that control the rate of chemical reactions in the body
What are Nucleic acids?
Made up of CHON and phosphate
- largest, most complex molecules in organisms (DNA, RNA)
What is passive transport?
Movement of molecules that do not require an input of energy
What is diffusion?
Natural movement of molecules from high concentration to low. (anything but water)
What is osmosis?
Movement of water molecules across a membrane due to a concentration gradient (high to low) only with water
What is active transport?
energy is used to move molecules against the concentration gradient (low to high)
What is ingestion?
taking food into the body
What is mechanical breakdown in organisms?
physical breakdown of food by chewing
What is chemical breakdown in organisms?
Enzymes breakdown food into its smallest particles through hydrolysis
What is hydrolysis?
addition of water breaks down large food particles into its smallest form (become hydrolyzed)
What is a substrate?
The material on which an organism lives. Some attach to their substrates and some feed off of them.
What color does litmus paper turn in bases/acids?
Blue litmus paper turns red in acids.
Red litmus turns blue in bases.
