ex. plants and animals cannot carry out cellular respiration without oxygen
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
Nitrogen fixation the process of changing free nitrogen so that the nitrogen atoms can combine with other elements to form compounds that organisms can use.
Usable nitrogen varies within its local environment, it can be lost by
Some examples of natural processes that change environmental chemicals
Any change in the environment that produces a condition that is harmful to living things.
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
Contains 3 main elements: nitrogen, phosphorus, and potassium. Sometimes contains a fourth element: sulfur.
Chemicals used to kill pests. Pests are organisms that harm people, crops or structures.
A compound that dissolves in water to form a solution with a pH lower than 7.
Ex. vinegar, lemon juice.
A compound that dissolves in water to form a solution with a pH higher than 7.
Ex. hair conditioner, milk
The pH number of a solution indicates its acidity; it is a measure of the concentration of hydrogen ions (H-) in a solution.
The difference between one number and the next on the pH scale represents a 10-fold difference (logarithmic scale)
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.
3. A Universal indicator 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 rain is formed By the following:
This water than falls as acid rain.
Are compounds that contain carbon (there are a few exceptions!!)
Are compounds that do not contain carbon.
Are elements and compounds that organisms need for living, growing and reproducing.
There are about 9 nutrients that organisms need in large amounts, for example; carbon, hydrogen, oxygen, nitrogen, phosphorus, potassium, magnesium, calcium and sulfur.
Nutrients that organisms need in only minor or trace amounts, for example, selenium.
There are 4 important classes of organic compounds:
Are organic molecules made up of carbon, hydrogen and oxygen.
These elements form simple molecules like sugar or large, complex molecules like starch, cellulose and glycogen.
Compounds composed of many carbon, hydrogen and oxygen atoms. Examples are fats, oils and waxes.
Organic compounds made up of amino acids; protein molecules contain nitrogen, hydrogen, oxygen and carbon, sometimes sulfur.
Catalysts that control chemical reactions in organisms.
The building blocks of proteins
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)
There are different tests to use when testing for different organic molecules.
Use a solution called Benedict’s solution; it turns from blue to yellow-orange-red in the presence of organic molecules.
* Starch: Iodine solution turns from red-brown to blue-black.
* Fat/Oil: Fats and oils leave a spot on brown paper that light can pass through.
* Protein: Biuret solution turns from blue to purple to mauve.
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.
The reaction of a substance with water. ‘Hydro’ refers to water and ‘lysis’ refers to breakdown.
Anemones attach themselves to rocks and capture food with tentacles.
The material on which an organism moves or survives.
A layer of ozone (O3) in the atmosphere 15 to 50 km above the Earth’s surface protecting it from the Sun’s ultraviolet radiation.
Monitoring - means keeping track of something for a specific purpose.
- Chemicals are monitored to protect our water and air quality.
Indicator organisms include fish, plants, worms, insects, plankton (microscopic algae and tiny animals), protozoa, bacteria and viruses.
Microscopic organisms like bacteria can cause serious health problems when present in large enough numbers.
Are animals without backbones that live in water
Diversity of organisms decreases as pH increases and dissolved oxygen decreases.
The number of different species in an ecosystem.
These are most commonly monitored as indicators of water quality:
To solve how many ppms there is in a solution, use these steps.
1. Suppose I have 100g of a salt solution, and the solution has 205 ppm of NaCl (Salt). How many grams of salt is there in the solution?
2. First write out 205 ppm in a g/1,000,000 format = 205g/1,000,000g.
3. Now multiply the ratio from step two by the amount of solution in step one. 100g x 0.000205 = 0.0205g
4. In the 100g of salt solution there is 0.0205g of NaCl present.
When acidic deposits build up in ice and snow during winter. Once it melts in spring, the acid meltwater flows into aquatic systems lowering its pH level.
Toxins: (poisons) are substances that produce serious health problems or death when introduced into an organism.
Toxicity: describes how poisonous a substance is.
A measurement used to compare toxins. LD means lethal dose, ‘50’ represents 50%. LD50 is the amount of a substance that causes 50% of a group of test animals to die if they are given a specified dose of the substance all at once.
Air quality is determined by:
Are used to reduce SO2 emissions by 99%. SO2 reacts with limestone that converts it to gypsum used in manufacturing.
- Not a pollutant because of its natural presence but increases in concentration making it dangerous