Environmental Chemistry Topics 1-3 PDF

ENVIRONMENTAL CHEMISTRY Unit Overview: Where Biology and Chemistry Meet ◻ In Matter and Chemical Change, we looked at properties and changes of matter and how chemistry can be used to explain them. ◻ This unit we, will look at chemistry as it relates to biology and the environment. Let us...

ENVIRONMENTAL CHEMISTRY Unit Overview: Where Biology and Chemistry Meet ◻ In Matter and Chemical Change, we looked at properties and changes of matter and how chemistry can be used to explain them. ◻ This unit we, will look at chemistry as it relates to biology and the environment. Let us begin… What does chemistry have to do with biology? We are all made of chemicals Food also made of chemicals Broken down by digestive system into molecules that are absorbed into blood These chemicals or nutrients are used for: ❖Energy ❖Growth ❖Body- building Nutrients- essential for life ◻ Nutrients can be organic or inorganic Organic Compounds Organic Role in Nutrition Dietary Molecule Source Carbohydrates Energy source for Rice metabolism Grains Potatoes Fruits Protein Structural molecule Meat for body, helps Eggs chemical reactions Dairy Legumes Nuts Lipids Storage of unused Vegetable chemical energy oil Nut oil Legumes Elements for Healthy Bodies: Minerals ◻ Minerals you need a lot of is called a macromineral ◻ Minerals you only need a little of are called trace elements, which are found in enzymes and vitamins ◻ All living things need 16 naturally occurring elements ⬜ Plants need 18 elements ⬜ We need 22 elements Elements for Healthy Bodies: Calcium Phosphorus ◻Needed for ◻Bone formation strong bones ◻Forms and teeth compounds that ◻Nerve store and conduction release energy ◻Muscle (ATP) contraction ◻Blood clotting Elements for Healthy Bodies: Magnesium Potassium ◻Component of ◻Helps regulate Bones and teeth nerve signals and muscle ◻Essential for activity (heart enzyme rate) function ◻Protein ◻Helps regulate formation nerve function ◻Regulates acid/base Elements for Healthy Bodies: What is one crucial role for…. ◻ Sulphur? ⬜ Used in some amino acids ◻ Iron? ⬜ Red blood cells, regulates oxygen transport ◻ Iodine? ⬜ Major part of thyroid hormones that regulate metabolism Getting these Minerals ◻ As humans, we cannot extract the mineral directly from the ground ◻ But plants can… and do ◻ Root hairs specially designed to uptake and concentrate these minerals ◻ They are then transported to other parts of the plant where they are used to create organic compounds such as proteins, lipids and vitamins. ◻ Without plants, we would not be able to obtain the nutrients we need. Substrates ◻Other organisms get their minerals through absorbing them from a substrate ◻ A substrate is a material on which an organism moves or lives. ◻ Some organisms attach themselves to the substrate, others obtain their nutrients fromFor their substrate. example – the lichens in this photo are using the rocks as a substrate. Fertilizers: Nutrients for Plants ◻ Often, we help plants grow by giving them fertilizer ◻ Fertilizers imitate nitrogen cycle, adding nitrates, ammonia and urea ◻ Phosphorus provided as phosphate compounds Numbers on bag indicate percent of each substance ◻ Potash acts as Impact of Using Fertilizers ◻ Use of artificial fertilizers has increased amount of nitrogen in environment as much as 140 million tonnes/year ◻ What are the pros and cons of this use?  Pros Cons ◻ Increased plant ◻ Fertilizer and water growth can be an ◻ Land not normally expensive price for suitable for productivity farming, can yield ◻ Single crop = large crops when increased chance ⬜ High yield crops of impact by plants disease ⬜ Fertilizer used ◻ Pesticides can be ⬜ Properly watered used to reduce loss of crops, but are not without cost or  Harmful Algal Bloom Rapid growth of algae that can deplete the oxygen dissolved in the water and block sunlight required by other organisms in the aquatic ecosystem 16 Summary ◻ Living things need nutrients to survive ◻ These nutrients can be organic or inorganic ◻ We obtain our nutrients from our food which includes plants ◻ Plants are capable of absorbing minerals from the soil, and using them to make proteins, lipids and vitamins ◻ Fertilizers are one way that can be used to enhance plant growth, but their use in not without impact ◻Last Class ◻This Class ◻ Looked at ◻ Investigate the nutrients needed use and for living things movement of ◻ Organic vs pesticides and Inorganic Nutrients their impact on ◻ Exit slips from last the environment class ◻ Bioaccumulation ◻ Nitrogen Cycle ◻ Biomagnification ◻ DDT Pesticides ◻ Three types of pesticides ⬜ Herbicides: these chemicals are designed to kill plants. Some are selective (eg. Killex), while others are not (eg. Round-up) ⬜ Insecticides: these chemicals are designed to kill insects eg. Raid, DDT, dieldrin ⬜ Fungicides: these are designed to kill fungus Ingestion vs Absorption ◻ Ingestion – taking in a material. For us, this is equivalent to eating ◻ Absorption – this can occur in several ways: ⬜ Digestive tract ⬜ Respiratory tract (after inhalation) ⬜ Skin DDT ◻ DDT (dichlorodiphenyltrichloroethane) is an insecticide that kills mosquitos and other insects. ◻ Originally seen as great, was going to solve the problem of malaria ◻ Hand unforeseen consequences higher up the food chain due to BIOACCUMULATION and BIOMAGNIFICATION ◻ Birds feeding on insects were laying eggs with shells too thin to allow chicks Bioaccumulation vs Biomagnification ◻ Bioaccumulation is an increase in concentration of a material from the environment over time in an organism in a food chain ◻ Biomagnification is an increase in concentration of a pollutant from one link in a food chain to another ⬜ In order for this to occur, the pollutant must be long-lived, mobile, soluble in fats, and biologically active  DDT Restriction Four reasons restriction of DDT has been a struggle: 1.DDT helped reduce malaria incidence; incidence increased again after DDT banned 2.Replacements not as safe or effective 3.Substitutes are more expensive 4.Pesticide resistance is on the rise