1. Unit C Environmental Chemistry

2. Topic 1: Role of Substances
The most common chemical elements in living things are C, O and H
ORGANIC COMPOUNDS
Compounds that contain C
Exceptions: CO2, CO
INORGANIC COMPOUNDS
Compounds that do not contain C

3. Hydrochloric acid (HCl)
Classify each substance below as organic or inorganic
Key question: Does the substance contain carbon?
Substance
Organic or Inorganic?
Oxygen
Distilled water
Sugar
Carbon dioxide
Motor oil
Hydrochloric acid (HCl)
Rust
Glass
Fat

4. Types of Organic Molecules Carbohydrates Composed of C, H and O
Used to provide instant energy
Soluble in water
Ex: Sugar (C6H12O6)
Starch

5. Lipids
Composed of C, H and O
Used to store energy; saved for use at a later time
Insoluble in water
Eg. Oils and fats

6. Proteins
Composed of C, H, O and N
Made of units called amino acids
Each protein has its own number & arrangement of amino acids
Used for growth and repair; are a source of energy

7. Nucleic Acids
Made up of phosphates (P), ribose (sugar – C, H & O) and N-containing bases (A, T, G, C)
Largest and most complicated molecules found in living things
Eg. DNA and RNA

8. Nutrients
Elements and compounds that are needed for living, growing and reproducing
2 main types:
Macronutrients
Needed in relatively large amounts
Include compounds that contain C, H, O, N, P, K, Mg, Ca and S

9. Micronutrients
Needed in relatively small amounts
Include vitamins and minerals
Optimum amounts
Amount of a substance that provides an organism with the best health
Too much or too little can lead to problems

10. Nutrient
Use in plants
Use in animals N
-composition of proteins, DNA and chlorophyll
-leaf and stem growth
-composition of proteins and DNA
-growth and repair of tissues P
-root and flower growth
-cellular respiration and photosynthesis
-part of DNA
-composition of bones, teeth and DNA
-many metabolic reactions K
-early growth
-disease resistance
-chlorophyll production
-muscle contraction
-nerve impulses Mg
-composition of chlorophyll
-photosynthesis
-composition of bones and teeth
-absorption of calcium Ca
-cell wall structure
-cell division
-muscle and nerve function S
-production of fruits
-protein synthesis
-enzyme activation
-detoxification

11. What macronutrient are the plants missing? What can the farmer do?
A farmer noticed that his crops are not growing as well as they have in past years
The lower leaves are showing a distinct yellow striping and the plants are not as tall as they should be
He has been applying large amounts of P and K fertilizer, expecting to get high yields from his crops
Soil test show low levels of Mg and high levels of K.
High levels of K can interfere with the absorption of Mg by the plant
What macronutrient are the plants missing?
What can the farmer do?

12. Selenium (Se) is required in trace amounts
Prevents cellular damage
Strengthens immune system
Too little
More susceptible to cancer, heart disease
Keshan disease (enlarged, poor functioning heart)
Crohn’s disease
Too much
Selenosis
Nasea, Fatigue
Nerve damage
Cirrhosis of liver

13. How Organisms Take in Substances

14. Animals
Obtain nutrients from food
Ingestion
Process of taking food into our bodies
Digestion
Food is broken down into smaller pieces
Think back to chemistry…how can you speed up a reaction?

15. Food is broken down
Mechanically
Mouth & teeth
Chemically
Stomach and small intestine
Hydrolysis
Breakdown of a substance using water
Eg. C12H22O11 + H2O → 2 C6H12O6
Nutrients are absorbed through cell membranes and into the bloodstream
Blood carries nutrients to other cells

16. Plants
Obtain their nutrients from the soil and air
Diffusion
Passive process
Does not require energy
Movement of molecules from an area of higher concentration to an area of lower concentration

17. Osmosis
Diffusion of water across a semi-permeable membrane
Water moves from an area of high concentration to an area of low concentration
Passive process