Nitrogen Cycle
What is the nitrogen cycle?
The nitrogen cycle is how nitrogen travels around our ecosystem
What is DDT (not the full name)?
DDT is a pesticide/insecticide that was once commonly used to combat malaria-spreading mosquitoes as well as other disease-spreading insects. DDT eventually became a pesticide used in agriculture, and is still in use to this day
What is an acid and a base? What is considered neutral?
Acid - a compound that dissolves in water to form a solution with a pH LOWER than 7
Base - a compound that dissolves in water to form a solution with a pH HIGHER than 7
Neutral - a compound that dissolves in water to form a solution with a pH of 7
what are pollution and pollutants? What is the difference?
Pollutant: Cause of pollution
Pollution: a negative alternation that impacts living organisms
Persistent waste - pollutants, accumulate, cannot/takes a long time to break down
Non-persistent waste - can break down into non-harmful compounds
Why is nitrogen important to plant growth? How do humans enhance plant growth?
Plants use nitrogen to form amino acids, without these amino acids plants cannot grow as healthily
We use fertilizers that contain nitrogen to enhance growth
How did DDT enter the food chain?
DDT was sprayed into water. Zooplankton in the water absorbs the DDT. Those zooplankton are then eaten by larger animals who eat those animals and it travels up the food chain.
What is neutralization?
Neutralization is a reaction between an acid and a base that produces water and a solid compound called a salt
What is toxicity? What are the different types of toxicity?
Toxicity is the ability of a chemical to harm a living organism
Acute toxicity - when symptoms occur after one exposure to a chemical
Chronic toxicity - when symptoms occur after continued exposure to a chemical over time
What is a biological indicator? Provide an example
Organisms that can alert people of how to clean/polluted the environment is through their absence/presence. Examples: Aquatic worms, crustaceans, macro-invertebrates
What are Nitrates and Nitrites?
Nitrates and Nitrites are alternate forms of N
They are compounds containing both Nitrogen and Oxygen
What is Bioaccumulation and Biomagnification?
Bioaccumulation - The build-up of chemicals in one body over time
Biomagnification - Chemical remaining in the ecosystem, being passed on from one organism to another
What are some causes of acid rain?
- Chemicals originally in the atmosphere
- Natural causes
- Human activity (pollution)
What is LD50?
Lethal Dose 50 - refers to the dose of a chemical that will kill 50 percent of the population to which it is applied
Persistent: DDT, pesticides, heavy metals, plastics
Non-persistent: Food waste, wood, pesticides
What are some problems that come with using nitrogen fertilizers?
Too much nitrogen can cause pollution. Excess N can run off into bodies of water, causing rapid algae growth. When the algae die, it uses up a lot of the oxygen in the water. This results in fish suffocating due to a lack of oxygen.
DDT was an important discovery that helped with war efforts during WW2. It kept people safe from insect-borne diseases like malaria, typhus, and more.
What are things we can do to combat acid rain?
- Liming
- Legislation/Law
- Alternate energy sources
- Conserving energy
1625mg/kg
Explain what the nitrogen cycle is, the main stages of the nitrogen cycle, and what happens in those stages
The nitrogen cycle is how nitrogen travels around our ecosystem
Nitrogen Fixation - Converting N2 into biologically available forms, taking N2 from the air, Bacteria, and Lightning are the main causes of N2 change
Nitrification - Bacteria converting ammonia into nitrates and nitrites
Assimilation - Plants absorb N through the soil, Animals absorb N through eating plants
Ammonification - decomposers decompose animal excretion, decomposers convert excess N into ammonia
Denitrification - Putting N back into the atmosphere, Denitrifying bacteria convert nitrates/nitrites back into N
What are the factors that make DDT so harmful?
DDT is stored in fats and is insoluble in water. It will just stay in place and will not be washed away by rain. DDT is extremely effective but also non-selective. DDT will kill everything it has an effect on, not specific insects or pests. DDT can remain in the environment for years causing continuous harm to humans and animals.
What is PPM?
Parts per million / (mg/L) or (mg/kg)
Caffeine has an LD50 of only 130ppm in mice so why don't we ban caffeine from human consumption?
The LD50 of caffeine for humans is 2000 mg/kg. Caffeine is not as toxic to us as it is to other animals, and consuming the amount of caffeine required to kill a human is quite difficult considering one espresso shot only contains about 212mg of caffeine.