1. Give it a Try!
Select one of the symbols for the elements shown in Figure 1.1. Using the periodic table, record the name of the element.
In the computer lab, research how plants and animals use the element. HINT: An element may be used on its own or be part of a compound.
If possible, identify any beneficial and harmful effects of the element on living things, including humans.
Record your findings on a separate piece of paper.

2. Environmental Chemistry
Unit C

3. Key Questions
Over the course of this unit, keep the following questions in the back of your mind:
What substances do we find in local and global environments?
What role do these substance play, and how do changes in their concentration and distribution affect living things?

4. What is Environmental Chemistry?
Environmental chemistry is the study of how chemical substances make up the world around us
Chemicals are part of the process in all natural cycles and processes
Changing the concentration and types of chemicals present in our environment will have an impact on our environment and the distribution and abundance of living things in the environment

5. Chemicals in the Environment
Section 1.1

6. Chemicals in the Environment
With your group, come up with at least 5 examples of where we see chemicals in our environment.
For each example, describe what the role of the chemical is.
Our environment is made up of different chemicals
These chemicals will either support or harm living things

7. The Nitrogen Cycle
Nitrogen is an important element for living things. It can be found in DNA, amino acids, proteins, etc.
In the nitrogen cycle, nitrogen makes its way through our environment in different forms
A basic introduction

8. The Nitrogen Cycle
Nitrogen is found as an element in the air. However, plants cannot use nitrogen in this form, so it must be converted into another form to be useful.
Nitrogen fixation is the process by which some bacteria and algae separate nitrogen atoms from each other so they can form compounds with hydrogen and oxygen.

9. In your own words, write down the steps in the nitrogen cycle, starting with atmospheric nitrogen.
Add ground water into the cycle – link to nitrogen cycling and moving throughout the environment!

10. The Nitrogen Cycle
Atmospheric nitrogen is fixed by bacteria in the soil
Plants use the fixed nitrogen
Consumers then eat the plants and use the nitrogen to make new molecules, like proteins
Animal and plant waste is then used by decomposers who release nitrogen back into the soil
This nitrogen is again used by bacteria to start the cycle over; some nitrogen is released back into the atmosphere

11. Processes that Affect Environmental Chemicals
The nitrogen cycle is an example of how environmental chemicals change.
Think-Pair-Share
Can you think of at least 1 other example?
What are some ways that these cycles can be affected by humans or other factors?

12. Processes that Affect Environmental Chemicals
Both natural and human processes can change chemicals in the environment
Example: both exhaust from vehicles and forest fires can create an excess of carbon dioxide in the air and produce smog
Human impacts are especially interesting to many people because of pollution
Pollution is any change in the environment that produces a condition that is harmful to living things

13. Human Activities Agriculture
Farmers need to have an understanding of environmental chemistry
Many people use fertilizers which enrich soil so that plants will grow better
However, too much fertilizer can damage organisms, since the excess chemicals get into the water table and are even harmful to the crop itself
Example: Think about overeating. What happens to people when they overeat or undereat? They will get sick. The same principle applies to plants and other organisms. Too much of something is just as bad as not enough.
Why would too much be harmful to the environment and to plants?

14. Human Activities
Humans not only use fertilizer, we also use pesticides (herbicides, insecticides, and fungicides) to kill unwanted organisms
Implications?
A pest is an organism that harms people, crops, or structures
Some pesticides are not selective, they kill both pest and non-pest species

15. Human Activities Solid Wastes
Chemicals are introduced into the environment when we dispose of solid waste or wastewater (sewage/drain water)
This includes garbage collected from households, industry and commercial buildings.
Some solid waste can be recycled. However, most of it ends up in landfill sites

16. Sanitary Landfill Sites
In a sanitary landfill site, wastes are spread and compacted by bulldozers before they are covered by soil
These landfills use plastic liners and compacted clay to prevent drainage of waste products into the soil and groundwater

17. Waste Water
Much wastewater is produced in our homes and is then treated at a wastewater treatment plant

18. Fuel Combustion Coal, oil, and natural gas are fossil fuels
Non-renewable resource
When fossil fuels are burned they produce large amounts of carbon dioxide and water vapour
This burning of fossil fuels may also release pollutants
These can cause acid rain and other pollution in our environment

19. Homework Assignment
Check and Reflect Pg. 190
#1-3, 5-9, 11

20. Check and Reflect Pg. 190
Decomposers break down large nitrogen-containing molecules from dead organisms and animal waste into nitrogen that can be used to form useful compounds.
Pollution is any change in the environment that is harmful to living things.
The first number represents the percent of nitrogen compounds present. The second number represents the percent of phosphorous compounds. The third number represents the percent of potassium compounds.
Plastic liners and compacted clay are used to prevent solutions from entering groundwater.

21. Check and Reflect Pg. 190
Nitrogen compounds in the soil are taken up by plants and removed when the plants are harvested. Nitrogen compounds can be carried away from an ecosystem by water since they are very soluble. They can be changed by bacteria into nitrogen gas that returns to the atmosphere and can’t be used by plants.
Fossil fuel combustion releases nitrogen and sulfur compounds as well as carbon dioxide.
Fertilizers are used to supply nutrients to a nutrient deficient soil so that plants grow better.
Sewage has to be treated to remove substances that can have a harmful impact on living things in the environment.
Discuss

22. Acids and Bases
Section 1.2

23. Review Why is environmental chemistry important?
What are some processes or actions that can affect chemicals in the environment?

24. Acids and Bases
An acid is a substance that dissolves in water to form a solution with a pH lower than 7
The pH of a solution is a measure of the concentration of hydrogen ions in that solution
A base is a compound that dissolves in water to form a solution with a pH higher than 7
A neutral substance has a pH of 7 while in solution

25. The pH Scale Acidity is measured according to pH
The pH scale ranges from a pH of 0-14 (in most cases)
The difference between pH is on a 10-fold scale
Example: A solution with a pH of 3 is 10 times more acidic than a solution with a pH of 4

26. Measuring pH
Acid-base indicators or pH meters can be used to measure the pH of a solution
An acid-base indicator will change colour depending on what the pH of the solution is
Demo – vinegar and baking soda
Vinegar and Baking Soda – 3 of each, with phenophthalein, methyl violet, bromothymol blue

27. Neutralization
A neutralization reaction is a reaction between an acid and a base in which water and a salt is formed
Demo

28. Neutralizing the Effects of Acid Rain
Ordinary rain water is slightly acidic
This is because there is already a small amount of carbon dioxide in the air which will react with rain water to produce a very weak acid (pH = 5.6)
However, with an increase of pollutants in the atmosphere (especially SO4 and NO3), acid rain has become a major problem
Some areas of Canada have rain with a pH as low as 3

29. Homework Assignment
Check and Reflect Pg. 195
#1-7

30. Check and Reflect Pg. 195
A neutral solution is one that is neither acidic nor basic, it has a pH of 7. An acid is a compound that dissolves in water to form a solution with a pH below 7. A base is a compound that dissolves in water to form a solution with a pH above 7.
a) acid; b) base; c) neutral; d) base
Gases released can include:
CO2 that will form carbonic acid
SOx that will form sulfurous or sulfuric acid
NOx that will form nitric acid
Lemon juice is an acid, which means it has a pH less than 7.
A pH meter or universal indicator gives a more specific or accurate pH measurement than red or blue litmus paper.
Products are water and a salt.
a) acid could be added to the water to neutralize the base
b) there will be an effect on organisms, most likely some species will disappear while other will thrive in this new environment.

31. Common Substances Essential to Living Things
Section 1.3

32. Organic and Inorganic Compounds
Our bodies need about 25 elements to maintain our health and normal growth
These elements can be found in two types of compounds, organic and inorganic compounds
Organic compounds are compounds whose molecules contain carbon
Exceptions: CO, carbon dioxide, carbonates, and cyanides which are all inorganic
Inorganic compounds are compounds whose molecules do not contain carbon

33. Nutrients All living things need nutrients to survive
Nutrients are elements and compounds that organisms need for living, growing and reproducing
Some nutrients are needed in larger amounts than others
The nutrients that are needed in large amounts are called macronutrients (“macro” means large)
The nutrients that are still essential but needed in much smaller amounts are called micronutrients (“micro” means really small)

34. Macro Nutrients Nutrient In plants, it’s important in:
In humans, it’s important in:
Nitrogen (N)
Composition of proteins and chlorophyll
Leaf and stem growth
Composition of proteins and nucleic acids
Growth and repair of tissues
Phosphorus (P)
Root and flower growth
Cell respiration and photosynthesis
Composition of bones, teeth, and DNA
Many metabolic reactions
Potassium (K)
Stimulation of early growth
Starch and protein production and sugar movement
Disease resistance
Chlorophyll production and tuber formation
Muscle contraction and nerve impulses
Magnesium (Mg)
Composition of chlorophyll structure
Photosynthesis
Composition of bones and teeth
Absorption of calcium and potassium
Calcium (Ca)
Cell wall structure
Cell division
Blood clotting
Muscle and nerve function
Sulfur (S)
Production of fruits and grains
Protein synthesis
Enzyme activation
Detoxification

35. Plant Nutrients
Without these elements, plants would not be able to survive, or would not do very well

36. Maintaining the Right Level
There can be “too much of a good thing”!
In all living organisms nutrients are essential, but having too much of a nutrient can be just as harmful as not having enough of the nutrient
Examples:
Selenium is a micronutrient that is required in trace amounts in our diets. Too much of it can cause harmful effects, but too little of it can also be harmful.
High levels of potassium in the soil can be harmful to plants by preventing them from absorbing magnesium. But potassium is important to plants for growth and production of important compounds.

37. Optimum Amounts Remember Goldilocks and the Three Bears?
Goldilocks had to have it “just right”
This same principle applies to the ingestion of nutrients; there is an optimum amount
An optimum amount is the amount of that nutrient that provides the organism with the best health

38. Types of Organic Molecules
There are 4 main types of organic molecules essential for all living things
Carbohydrates
Lipids
Proteins and Amino Acids
Nucleic Acids

39. Carbohydrates
Carbohydrates are organic molecules made up of carbon, hydrogen and oxygen
They can be simple molecules, such as sugar, or large molecules, like starch, glycogen and cellulose

40. Carbohydrates
Glucose is a simple sugar that is made during photosynthesis
It is a simple carbohydrate
Cellulose, starch and glycogen are complex carbohydrates that are made up of many glucose molecules linked together

41. Lipids Fats, oils and waxes are lipids
These are compounds made up of many carbon, hydrogen, and oxygen atoms
These are used for long-term energy storage

42. Proteins and Amino Acids
Proteins have many functions
They are used for growth and repair, and as a source of energy
Main component of enzymes

43. Proteins and Amino Acids
An organic compound made of smaller units that are called amino acids
Each protein has its own number and make-up of amino acids

44. Nucleic Acids
The largest and most complicated molecules found in living things
DNA is an example of a nucleic acid
They are made up of three sub-parts
Phosphates
Simple sugar
Nitrogen-bases

45. Homework Assignment
Check and Reflect Pg. 203
#1-9

46. Check and Reflect Pg. 203
Organic compounds are complex molecules that contain carbon.
A micronutrient is a substance that is essential for plant and animal growth and development in very small amounts. Selenium is an example of a micronutrient.
Carbs – C, H, O; lipids – C, H, O; proteins – C, H, O, N; nucleic acids – C, H, O, N, P
Phosphorous deficiency is a possibility because it is important in root and flower growth.

47. Check and Reflect Pg. 203
In plants, too little potassium can prevent early growth, reduce disease resistance, reduce starch and protein production, reduce sugar movement, and reduce chlorophyll production. Too much potassium can interfere with the absorption of magnesium.
Selenium is needed in small amounts in humans to prevent diseases such as cancer, heart disease, cystic fibrosis, and damage by hydrogen peroxide. In large amounts, it can cause reproductive problems, death in fish and waterfowl.
a) carbohydrate; b) DNA; c) lipids
a) nutrient deficiencies could be nitrogen, magnesium, or potassium because they are all important in chlorophyll production
b) soil testing would likely be the next step.
Glucose was detected.

48. How Organisms Take in Substances
Section 1.4

49. Review What are nutrients? Why are they important?
What impact does pollution have on the environment? Why is this important to us?

50. Uptake of Substances by Plants
Plants need nutrients just like animals, but unlike animals they can’t move around to get them
So how does this work?
Plants use active and passive transport through their roots and leaves
Passive transport is the movement of molecules along a concentration gradient
Active transport requires energy to move molecules

51. Diffusion
Diffusion is the movement of particles along a concentration gradient
From an area of higher concentration to an area of lower concentration

52. Osmosis
Osmosis is a special type of diffusion that involves the movement of water along a concentration gradient
The water moves from the soil into the roots because the concentration of nutrients is much higher in the roots, and therefore the concentration of solvent (water) is low

54. Active Transport
Active transport moves molecules against a concentration gradient
This requires energy!!!
Plants use active transport to get nutrients from the soil
There is a large concentration of nutrients in the roots compared to the soil, so this is against a concentration gradient
Marshmallows in container with hole at bottom - have student volunteer place marshmallows back into container while they are still leaving through diffusion

55. Ingestion and Absorption by Animals
Animals get their essential nutrients from the air they breathe and the food they ingest
The food is broken down mechanically (chewing) and chemically (stomach and intestines) and absorbed into the bloodstream

56. Nutrients
Where organisms live affects how and when they obtain nutrients
There are many adaptations that help organisms obtain nutrients
With your group think of 3 specific examples that help organisms obtain nutrients

57. Substrates A substrate is the material on which an organism lives
Some organisms are attached to their substrates (ex. plants), others move around

58. Homework Assignment
Check and Reflect Pg. 209
#1, 3-8

59. Check and Reflect Pg. 209
a) diffusion is the movement of substances from an area of higher concentration to an area of lower concentration
b) osmosis is the movement of water across a semi-permeable membrane from an area where there are more water molecules to one where there are fewer water molecules
c) active transport is the transport of materials across a cell membrane from an area of low concentration to an area of higher concentration. This process requires energy
When a human ingests food, the food is digested or broken down into smaller particles that can be absorbed into the bloodstream. This process begins in the mouth and continues in the stomach and small intestine.
Hydrolysis enzymes speed up the rate at which large organic molecules break down.

60. Check and Reflect Pg. 209
Plants take in water from the soil by osmosis. Water moves from the soil where there are more water molecules into the plant’s roots where there are fewer water molecules.
a) both active transport and diffusion are processes by which materials can enter plant’s’ roots.
b) diffusion is passive (along a concentration gradient) so no energy is required; active transport requires that the plant (cells) uses energy to move the nutrients against the concentration gradient
Red snow algae photosynthesize. They have lots of sunlight in the summer, as well as water from the melting snow for photosynthesis.
a) Discuss what is a good controlled variable
b) The manipulated variable is the temperature, while the responding variable is the speed at which the material moves or the time it takes the diffusing substance to move a certain distance.
c) If the temperature _______________, then the diffusing material diffuses _____________ because the molecules are ______________.

61. Section Review
Pg. 211
#1-10