Unit 3: Environmental Chemistry Flashcards
What are the parts of the Nitrogen Cycle
- Plants absorb nitrates from the soil through their roots
- Nitrates are converted to amino acids, building locks for proteins. Consumers rely on plant protein for energy
- bacteria and decomposers break down protein in dead organisms, converting them into nitrates
How are organisms able to use Nitrogen?
Nitrogen-fixing bacteria join nitrogen to other elements.
Found in the plant nodes or nodules of legumes such as peas, beans, clover and alfalfa, convert nitrogen from the air into nitrates. Lightning, too, converts nitrogen gas into nitrates
What are the parts of the Carbon Cycle?
- carbon passes from environment into living thing sand back
- carbon dioxide used during photosynthesis to make food (glucose sugar)
- Food is eaten by consumers, broken down by cellular respiration into carbon dioxide gas
What is fertilizer?
- a substance that enriches soil
- made of nitrogen, phosphorus, potassium
How does fertilizer affect the environment
too much can damage organisms in soil and crops, can also get into ponds, streams etc.
What are pesticides
Pest - organism that harms people, crops, structures
Pesticides - used to kill and control pests, some kill pests and non-pest species
- some pests become resistant to pesticides
Ways chemicals get into the environment
- Solid wastes - solid garbage from households, industrial plants etc.
- Wastewater - major pollutants deplete oxygen in water and poison water. With oxygen, bacteria decompose sewage. With too much sewage, oxygen is used up and organisms die
- Fuel Combustion - Fossil fuel, non-renewable formed from dead plats and animals. When burned, they produce CO2 and water vapour
(hydrocarbon + oxygen = carbon dioxide + water +ENERGY)
What is wastewater?
- contains dissolved and undissolved effluent, must be treated
- with heavy rainstorm, overflow can cause untreated water to enter bodies of water
What are the tree steps of the treatment process
- Physical - large material is filtered by screens
- Biological - organic sewage is decomposed through bacteria
- Chemical - added to remove phosphates and nitrates
What is sour gas
- hydrogen sulfide
- found in natural gas
- poisonous
What are acids
- Acids are compounds that release hydrogen ions H+ when placed in water. The more hydrogen ions are released, the greater the acidity of the compound.
- Acids tend to be sour in taste and are readily soluble in water.
What are bases
- Bases are compounds that release hydroxyl ions (OH)- into water.
- Bases are slippery to the touch, bitter in taste, and soluble in water.
What is neutralization
- Strong acids and strong bases are corrosive and can be dangerous if not handled properly.
- a strong acid can be neutralized with a strong base.
- involves mixing an acid with a base to produce salt and water.
what’s the difference between organic and inorganic substances
organic compounds contain carbon (excluding carbon dioxide and carbon monoxide)
What are the major elements of organic compounds
carbon, oxygen and hydrogen
What is substrate
the material that living this live on and obtain their substrates
What are Macronutrients
elements required in fairly large amounts. Examples include Carbon, Hydrogen, Oxygen, Nitrogen, Phosphorus
What are Micronutrients
elements required by living things in trace or extremely small amounts.
Examples include Calcium, Iron, potassium, Vitamins
What are Carbohydrates
- Are made up of Carbon, Hydrogen, and Oxygen
- Complex carbohydrates are made of many glucose molecules.
- Provide energy
What are lipids
- Also made up of Carbon, Hydrogen and Oxygen
- Our bodies store food in the form of fat
What are Proteins and Amino Acids
- Made up of Carbon, Hydrogen, Oxygen and Nitrogen
- Are made from amino acid units joined together
- Used for growth and repair
What are Nucleic Acids
- Are the largest most complicated molecules found in living things
- Two important nucleic acids are DNA and RNA.
- Heredity and controlling a cell’s activities.
How do plants and animals absorb nutrients into their cells
Plant roots - chemotropic, respond to chemical nutrients and grow towards source, once close, water bring nutrients to roots
What is hydrolysis
- breaking down complex molecules unto simple molecules using water
What is water used for
- Human drinking water
- Recreation such as swimming
- Livestock drinking water
- Irrigation
- Protection of aquatic life
What is water used for
- Human drinking water
- Recreation such as swimming
- Livestock drinking water
- Irrigation
- Protection of aquatic life
What are biological indicators
- used to determine water quality
Invertebrates - animals without backbones, different invertebrates prefer different conditions
What are Microbiological Indicators
Microscopic organisms such as bacteria can cause serious health problems if they are present in high enough numbers.
What Chemical factors affect organisms
- Dissolved oxygen
- Acidity
- Heavy metals
- Plant nutrients
- Pesticides
- Salts
What factors determine the level of dissolved oxygen
- Temperature
- Turbulence
- Photosynthesis
- # of organisms
What is the LD50
- lethal dose 50, the dose at which 50% of animals die when given a specific dose at once
Sulfur Dioxide, Nitrogen Oxides, Carbon Monoxide
Sulfur Dioxide
- can form smog and acid rain
- formed by industrial processes
- 99% can be transformed by scrubbers
Nitrogen Oxide
- can form smog and acid rain
- manly formed from vehicle combustion
Carbon Monoxide
- Colourless, odourless gas
- chemical containing carbon burn they form carbon dioxide and monoxide
- Carbon monoxide formed when there isn’t enough oxygen
What is Ozone
Atmospheric Ozone - prevents ultraviolet rays from reaching earth
Ground Level Ozone - forms when oxygen reacts with volatile organic compounds, large quantities can cause lung disease and respiratory problems
What is the Greenhouse Effect
- natural phenomenon that helps regulate the temperature of our planet
- sun’s heat is trapped in atmosphere by greenhouse gases like water vapour and carbon dioxide
What is Global Warming
- greenhouse gases that are released into the atmosphere through human activity
- Increased greenhouse gas concentrations may be resulting in more heat being trapped in the atmosphere and increasing global temperatures
What might happen if global warming returns
- Changing biomes
- Sea level rise
- Extreme heat waves
- Increased drought
- Higher frequency of extreme weather
How does air transport substances
- Release of the chemical at the source
- Dispersion of the chemical in the atmosphere (the chemicals scatter in all directions)
- Deposition of the chemical in soil or water
What factors determine the direction and distance chemicals travel in the air
- pollutant’s properties
- wind speed
- direction of prevailing winds
What factors determine the direction and distance chemicals travel in the air
- pollutant’s properties
- wind speed
- direction of prevailing winds
What is the First Zone in terms of ground water
Unsaturated
- near the surface
- spaces between soil contain both air and water
What is the second zone in terms of ground water
Saturated - all spaces filled with water - water is called ground water - top of groundwater zone is called water table - moves slo - contaminants can concentrate over time well use ground water
What determines the movement of ground wtaer
- number of pores
- Connection between pores
How are substances transported in surface water
- substance easily dissolved in water can be carried away and dispersed by water
- some substances that don’t easily dissolve become attached to soils
- they sink and become more concentrated at the source
How are substances transported in soil
- some evaporates
- some soaks into the soil and is taken up by plants
- some runs onto the street or into a stream
- some soaks through the soil and moves downward, may dissolve substances. This liquid is referred to as leachate.
What are some common leachates
Natural elements - Iron, calcium, selenium
Organic Pollutants - pesticides, solvents made by humans
Heavy Metals - lead, mercury, cadmium, inorganic fertilizers, household chemicals and detergents
What are dispersion and dilution
Dispersion - spread substance evenly out over large area
Dilute - add plenty of water to lower concentration
What is Biodegration
- breaking apart living things
ex. leaves are broken down/decomposed by micro-organisms. Bacteria and fungi act on leaves and change them into nutrients for soil
What are the two types of bacteria
Aerobic
- requires oxygen
- use oxygen to decompose
Anaerobic
- live without oxygen
- breakdown polychlorinated compounds in landfills, done without air or oxygen
What conditions make Bacteria better decomposers
- Warm to high temperatures
- Moist conditions
- Adequate supply of oxygen
What is phytoremediation
- using green plants to reduce the concentration of harmful chemicals
Example
Sunflowers - used in Chernobyl to remove radioactive materials from the soil and groundwater
Cattails- have specialized root systems that absorb pollutants in stagnant water and break them down into safe, usable forms.
What is photolysis
- breakdown of chemical substances by sunlight
ex. Certain plastics are made of chemicals that when exposed to light, react and break down into safe forms.
What is Biomagnification
- Chemicals that enter the environment often end up in the food chain of living organisms.
- Biomagnification is the increase in concentration of a chemical or an element as it moves up the food chain
Example
Mercury emissions from coal-fired power plants end up in lakes and are absorbed into the bodies of organisms in a food chain
