Our environment is made up of chemical compounds. Yes, everything is a chemical! (mind blown)
Our environment is made up of chemicals
Example: Water is a chemical that is essential to life
Natural and human processes change the chemical composition of the environment
Name three natural processes and three human processes that alter the chemical composition of the environment
All living things are made up of chemicals
Therefore all living things depend on chemicals to survive
ex. plants and animals cannot carry out cellular respiration without oxygen
However certain chemicals can also harm the environment, either produced naturally or by human activity
ex. volcanoes release large quantities of carbon dioxide, sulfur dioxide and ash – all chemicals
ex. Gasoline used in cars and pesticides used for crops all add harmful chemicals to the environment
Elements (Ex. oxygen) are pure substances that cannot be broken down into other substances. Elements can join together and form chemical compounds (O2, H2O, CO2).
Living things use and reuse chemical compounds “trading” them back and forth like a trading card.
Repeatedly trading elements back and forth throughout an ecosystems forms a cycle.
Almost all organisms need nitrogen. It comprises about 78% of the air we breath, yet we can’t use it!
Free nitrogen aka nitrogen gas (N₂) is pretty boring, and non-reactive.
Free nitrogen has to be made usable or ‘fixed’
Nitrogen fixation the process of changing free nitrogen (N₂) so that the nitrogen atoms can combine with other elements to form compounds that organisms can use (NO₂, NH₄)
Plants cannot use free nitrogen (N₂); they can only use nitrogen when it is combined with other elements like hydrogen and oxygen.
Bacteria located on roots of some plants separate nitrogen atoms so that they are free to combine with other elements to be used by plants.
Plants use nitrogen-containing compounds
Animals eat these plants
Animals’ bodies use the nitrogen to make more complex substances like proteins
Decomposers break down the large nitrogen-containing molecules into simpler nitrogen compounds in dead organisms and waste.
Some nitrogen-containing compounds are broken down by bacteria in the soil and released into the air as free nitrogen.
The cycle begins again.
Invented the Haber process, whereby nitrogen can be fixed synthetically. This invention alone has increased the yield of food stocks, if you are alive and eating there’s a good chance it’s due to this man!
Additionally, Fritz also invented the use of chlorine gas as a chemical weapon, which was used in the first world war. Chlorine gas binds with the mucous of your lungs to create Hydrochloric Acid.
Conversion to free nitrogen by bacteria
Becoming dissolved in water which carries it away or deep into soil, unreachable by plants
Harvesting of plants (no decomposition of plants on farmer’s field)
Some examples of natural processes that change environmental chemicals
Your body's metabolism
Any change in the environment that produces a condition that is harmful to living things.
Releases chemicals into the air and soil
Some of these chemicals can be broken down naturally; some cannot and cause long-term problems, becoming major issues.
Any subject of importance about which people have strong, conflicting, points of view.
A substance that enriches soil so that plants will grow better. Bags of fertilizer show 3 numbers in this format
ex 10 -15 - 20 (first is N, second is P, third is K)
Contains 3 main elements: nitrogen, phosphorus, and potassium. Sometimes contains a fourth element: Sulfur.
Fertilizers can be natural or synthetic (man-made)
Too much fertilizer will damage organisms or ponds, streams and lakes that it enters through runoff.
General term for chemicals used to kill pests. Pests are organisms (Plant or animal) that harm people, crops or structures.
Herbicides kill or control weeds.
Insecticides kill or control insects.
Fungicides kill fungi.
Pesticides are non-selective, meaning they kill pests and non-pests
Can stay in the environment for a long time
Solid waste is the garbage collected from households, industrial plants and commercial buildings; from machinery to plastic bottles.
Solid wastes end up in the following:
Hazardous wastes are burned in incinerators (thus, contributes to air pollution)
Sanitary landfill sites that have plastic liners and compacted clay that prevent rainwater and groundwater with dissolved wastes in them from leaking into the soil.
Some solid wasted are reused or recycled
Sewage is wastewater containing dissolved and undissolved materials from your kitchen, bathroom and laundry.
Sewage moves by pipes to various locations:
Septic tank - is an underground container where bacteria break down the organic materials before it is moved out to the soil.
Sewage Treatment Plants - treat wastes from homes, businesses and industries, then returns the water to a water source as effluent (ex. river)
Storm sewers - are large pipes that collect the large amounts of rainwater from street drains, which go directly into rivers and lakes without treatment.
Liquid waste or sewage discharged into a river or the sea
Is the burning of fossil fuels (formed from dead plants and animals).
Fossil fuels that are mainly made up of the elements hydrogen and carbon
Coal (C₂₄₀H₉₀O₄NS) , Gasoline (C₈H₁₈) and natural gas (CH₄)
Release large amounts of carbon dioxide and water vapour, as well as sulfur dioxide, nitrogen oxides and traces of mercury and lead which are pollutants.
Natural gas processing (common in Alberta)
Natural gas is composed of compounds like methane, ethane, propane and butane, also nitrogen gas, carbon dioxide, hydrogen sulfide, helium and traces of mercury.
Natural gas is processed to separate these components
Natural gas containing hydrogen sulfide (sulfur - think smelly farts!)
Natural gas not containing hydrogen sulfide
Draw a mind map of the 5 ways humans introduce chemicals into the environment
Human bodies need 25 elements
Carbon, oxygen and hydrogen are the most common elements of living things, they form:
Sugar / Starch
Fat / Oils / Wax
Molecules that always contain Carbon, most also contain Hydrogen (there are a few exceptions!!)
Molecules that do not contain carbon.
There are many more organic than inorganic compounds on Earth!
Any element or compound that organisms uses for living, growing and reproducing.
There are about 9 nutrients that organisms need in large amounts:
Carbon, hydrogen, oxygen, nitrogen, phosphorus, potassium, magnesium, calcium and sulfur.
Nutrients that organisms need in small or trace amounts, for example, selenium. This also includes all vitamins, for example, vitamin c.
Too little, but also too much of a nutrient can be damaging
Optimum amounts of a substance is the amount that provides an organism with the best health.
Recall that there are 4 important classes of organic compounds:
Lipids (AKA fats)
General term for organic molecules made up of carbon, hydrogen and oxygen.
Simple carbohydrates or monosaccharides, a few examples:
Fructose (C₆H₁₂O₆) - yes same elements as glucose!
When simple carbohydrates link together they can form disaccharides :
Complex carbohydrates or polysaccharides, a few examples:
Starches (C₆H₁₀O₅)ᴺ - A Glucose chains
Cellulose (C₆H₁₀O₅)ᴺ - B Glucose chains
Glucose is a simple sugar made by plants through photosynthesis.
Starch, cellulose and glycogen are composed of many glucose molecules joined together.
General term for organic molecules made up of many carbon, hydrogen and oxygen atoms. (C₅₅H₁₀₄0₆)
fats, oils and waxes
our skin produces oils / plants produce corn and peanuts that contain a lot of oils.
cell membranes are made of lipids hence why it’s called a phospholipid bi-layer.
General term for organic compounds made up of amino acids; protein molecules contain nitrogen, hydrogen, oxygen and carbon, sometimes sulfur.
Used for growth, repair and energy
They are the main component of enzymes.
Catalysts that control chemical reactions in organisms (Salivary Amylase, Protease)
The building blocks of proteins
Each protein contains its own number and arrangement of amino acids (between 40 and 500 amino acid units)
20 different kinds of amino acids are common in protein molecules
The largest and most complicated molecules found in living things.
All cells contain 2 important nucleic acids:
i. Deoxyribonucleic acid (DNA)
ii. Ribonucleic acid (RNA)
These 2 are made up of phosphates, a simple sugar called ribose and nitrogen-containing molecules.
These 2 play a major role in heredity and cell’s activities.
Draw a mind map of common compounds found in living things (biotic)
There are different tests to use when testing for different organic molecules.
Benedict’s solution - turns from blue to yellow-orange-red in the presence of organic molecules.
Iodine solution - turns from red-brown to blue-black.
Fats and oils - leave a spot on brown paper that light can pass through.
Biuret solution - turns from blue to purple to mauve.
The material on which an organism moves or survives.
Some organisms are attached to their substrate
Ex. sea anemone attaches to rock, yet uses tentacles to capture its food
While other organisms obtain nutrients from their substrate.
Ex. Bread mould breaks down the molecules of its substrate, the bread, to obtain nutrients.
Plants and animals rely on their environment
Plants take in inorganic compounds to make organic compounds
Consumers rely on plants and animals to obtain the compounds they need
Does not require a plant to use energy. Includes 2 processes: diffusion and osmosis.
The movement of molecules from an area of high concentration to an area of low concentration. ( evening out or balancing of the concentration of substances.)
When water moves from an area of high concentration to an area of low concentration.
When plants require energy to move nutrients from areas of low concentration to areas of high concentration.
The process of taking food into our bodies.
Organisms break down food mechanically as in chewing, and chemically as with the use of enzymes in the mouth, stomach and small intestines.
The reaction of a substance with water. ‘Hydro’ refers to water and ‘lysis’ refers to breakdown.
A substance has been hydrolyzed when it has been broken down by hydrolysis.
Nutrients are absorbed through cell membranes and into the blood stream.
A compound that dissolves in water to form a solution with a pH lower than 7.
Example : lemon juice
A compound that dissolves in water to form a solution with a pH higher than 7.
Example : milk
The pH number of a solution indicates its acidity; it is a measure of the concentration of hydrogen ions (H-) in a solution.
pH range is usually from 0 to 14
pH of 1 is very acidic; for example battery acid
pH of 14 is very basic or alkaline; for example household ammonia
pH of 7 is neutral (neither an acid or a base); for example water
The difference between one number and the next on the pH scale represents a 10-fold difference (logarithmic scale) meaning that a solution with a pH of 9 is 10 times more basic than a solution with a pH of 8. Also, a solution with a pH of 2 is 10 times more acidic than one with a pH of 3
1. A pH meter is a probe attached to a meter. You submerge the probe in the liquid and get a pH reading on the meter.
2. Acid-base indicators are substances that change colour when they are placed in solutions.
blue litmus paper turn red in an acid
red litmus paper turns blue in a base
3. An indicator (ex Universal indicator, or Phenol red, or Bromophenol Blue) is a mixture of indicators that change colour over a wide pH range. You add a few drops of the indicator and compare its colour change with the colour chart to determine its pH.
Is the reaction between an acid and a base that produces water and salt (neutralization products).
Acid + Base → Salt + Water
ex. HCl + NaOH → NaCl + HOH
Strong Acid + Strong Base = pH 7 (water + salt)
Strong Acid + Weak Base = Weak Acid
Strong Base + Weak Acid = Weak Base
Weak Acid + Weak Base = pH 7 (water + salt)
Acid rain is formed By the following:
When sulfur dioxide combines with water to form sulphuric acid (H₂SO₄)
When nitrogen oxides combine with water to form nitric acid (HNO₃)
When carbon dioxide dissolves in water to form carbonic acid. (H₂CO₃)
This water than falls as acid rain.
Ordinary rainwater is slightly acidic with a pH of about 5.6, rain that has a pH less than 5.0 is considered acid rain.
Lakes can be neutralized by adding lime (calcium hydroxide). The acidic water and the basic lime react forming water and salt (neutralization products)
High concentrations of phosphorus and nitrogen affect the amount of dissolve oxygen.
Sewage and runoff from fertilizers increase the growth of algae and green plants. As they increase, more die. This organic matter is now food for bacteria, using up more oxygen. Oxygen decreases, fish and aquatic insects cannot survive.
Some pesticides have long-term effects, but most are designed to last only one growing season, to be broken down by bacteria therefore are no longer toxic.
Many cause pesticide-resistant pests to develop and quickly, because of their rapid reproduction
Can remain in tissues of organisms
Allow biomagnification to occur
Can become mixed together to form a more toxic.