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Temperate rainforest ecosystem and the nitrogen cycle

Summary
Map a forest food web of living things, then follow nitrogen from the body of a salmon into forest trees, using molecule models.
Materials

Materials in the activities

Procedure

Look at map of regions of the world (called Biomes).
Try https://askabiologist.asu.edu/sites/default/files/resources/articles/bi… (from this article - https://askabiologist.asu.edu/explore/biomes) then https://cdn.britannica.com/38/102938-050-6B5388D9/distribution-biomes.j… for terrestrial (Earth, not water) biomes.
Our planet has distinct regions with their own climate - temperature, rainfall, amount of sunlight.
"Climate is what you expect Weather is what you get"
Temperate forest biome includes us. We are rainforest as our rainfall is higher than 1.5m/year.

Sun's angle on Earth activity shows how the sun is a major influence on the temperatures and weather in each of the Biomes
Because the regions have different climates, the living things that can survive there are different.

Sitting in a circle, do the Food web model activity.

Salmon is a keystone species, important for the entire food web of the forest.
Do the activity to show molecule models to show nitrogen moving through the food web.

Additional info
Temperate rainforest soil is rich compared to tropical rain forest soil (salmon nitrogen, also colder and more acidity from coniferous needles, so decomposition is much slower, and more of the nutrients are found in the soil). Tropical growth so fast that every scrap of nutrient is used.

Saharan sand brings phosphorus to the tropical rainforest of South America! It is carried on winds high in the atmosphere across the Atlantic Ocean.

Grades taught
Gr 2
Gr 3

Flight and Newton's Laws

Summary
Make paper airplanes and hoopsters to learn and hypothesize about how Newton's Laws apply to flight.
Procedure

Make flying things, and figure out how they fly.

Paper airplanes
Discuss thrust, drag, gravity and lift, and how Newton's Laws apply in each resultant force.
Adapt the wings of the plane to change the way it flies. Explain in terms of Newton's Laws.

Hoopsters
The air moving around the loops gives it lift so that it can fly for a while (though exactly how unclear to me).
Air resistance eventually slows it down and gravity brings it to the ground.

Birds and flight
Birds glide for the same reason that paper airplanes fly. They also push air to take off and manoeuvre.
Air seems like nothing to us as we are heavy. When a light bird pushes against air particles, they are small enough that the push makes them move.
Just as adjusting your plane changes the flight, birds move their feathers to change their flight path.
And depending on which way they push, they can make amazing maneuvers in the air.
Watch slow motion of birds flying: https://www.youtube.com/watch?v=qThIyj1mLfs.
Note: the shape of birds’ wings are different on the downstroke and the upstroke.Feathers (if time)

Grades taught
Gr 4
Gr 5
Gr 6

Solar panel

Summary
Light a bulb or turn a fan with a solar panel, with light from a flashlight or lightbulb.
Materials
  • solar panels (mine are 0.3W 5V from AliExpress)
  • flashlight/light bulb
  • LED bulbs including a low voltage 'super red'
  • optional: small fan (test first) - mine is a toy windmill attached to this generator
Procedure

Test before use to make sure the solar panel makes enough power to light the bulb/turn the fan.

Cross the solar panel wires with the LED terminals, matching black to black and red to red, and tape to the tabletop.
Shine the flashlight or light bulb on the solar panel to make electricity which can turn on the LED light/turn the fan. An incandescent bulb will light the LED more brightly and be able to turn the fan, whereas an LED flashlight will likely not turn the fan.

The light energy of the flashlight/lightbulb is converted to electrical energy in the solar panel, and back to light energy in the LED bulb.

Discuss the energy transformations, from light energy to electrical energy to light (or motion) energy.
Discuss renewable energy sources of electricity.

Grades taught
Gr 4
Gr 5
Gr 7

Energy from fossil fuels and renewable sources

Summary
Model how fossil fuels release carbon dioxide. Build circuits with wind turbines and solar panels.
Procedure

Light a candle. It exhibits the same chemistry as burning fossil fuels (wax is made from oil).
Use molecular models to show how burning fossil fuels makes carbon dioxide.
Carbon dioxide is a greenhouse gas - it soaks up heat leaving Earth (infra red) and re-emits it back in all directions. About half of that energy goes out into space, and about half of it returns to Earth and heats it up.

The amount of CO2 in the air determines how acidic our oceans are.
Model ocean acidification and how it is reversible.

Making energy without burning fossil fuels:
Build a model wind turbine.
Build solar panels into a circuit.
These renewable sources of energy need to replace fossil fuels to lower CO2 in the air and our oceans again, and reverse global warming.

For an extended lesson with free play, use batteries as a source of electricity, along with wires, lights and motors:
Do the electric circuits and motor free play activities.

Discussion on sources of renewable electrical energy:
Wind turbines account for about 4% of BC’s electricity generation capacity.
Most of BC's electricity comes from water: hydroelectric power accounts for 87% of electricity in BC.
Non-renewable: BC also still burns natural gas to make electricity. The hot combustion products drive a turbine to generate electricity.

Look at a live interactive map of Earth’s winds to discuss good places for wind power: https://earth.nullschool.net/#current/wind/surface/level/orthographic=-…
Hydroelectric power video: https://www.youtube.com/watch?v=OC8Lbyeyh-E

Grades taught
Gr 4
Gr 5
Gr 7

Mineral testing

Summary
Test minerals for hardness, streak, with the acid test (for carbonates). Sort minerals by lustre and crystal shape.
Procedure

Introduction:
Rocks may be made up of one kind of chemical, or a mixture of chemical types. The different chemical types are called minerals.
Minerals have different properties. To help identify a rock, geologists look at the minerals in it.
There are several mineral tests.

Make stations of different mineral tests for students to move through:
Two or three stations with hardness/streak - test to identify minerals
One carbonate acid test station - test carbonate and non-carbonate minerals/rocks/shells in vinegar
One crystal shape station - magnifers and microscope to look closely and find crystal shapes
One lustre station - sort unlabelled minerals by lustre

Review:
The minerals tested have different properties. Geologists use these tests to find out what minerals are in a rock they find.
As rocks go through the rock cycle, their minerals are separated by their different chemistry (for example, some melt at higher temperatures than others). Minerals are mixed together again as they sediment.
Different rocks have different mixes of minerals.

Optional:
Look at the chemical formula of the minerals, which shows what atoms are in it.
Which minerals might be used for making copper wires? (copper=Cu)
Which minerals might be extracted for iron, to make steel? (iron=Fe)

The chemistry of a carbonate mineral is CO3. Carbonate rocks can be made from living things. Show limestone forming from shells.

Attached documents
Mineral testing worksheet.pdf
Grades taught
Gr 5

Mineral lustre

Summary
Sort minerals by their lustre (surface appearance).
Procedure

Give students an assortment of minerals and a sorting sheet.
Ask them to look closely at the surface texture, and sort the minerals onto the sheet.
It doesn't matter if they don't get it exactly right (it takes much experience). The point is to notice different surface textures and reflectiveness in different minerals.

The technical lustre descriptions:
(from https://www.minerals.net/resource/property/luster.aspx)

Metallic - Minerals with a metallic luster are opaque and reflective, like metal.
The metallic elements, most sulfides, and some oxides belong in this category.

Submetallic - Describes a mineral that is opaque to nearly opaque and reflects well. Thin splinters or sections of submetallic minerals are translucent.

Vitreous (also called glassy) - Minerals with a vitreous luster have reflective properties similar to glass.
This luster accounts for roughly 70 percent of all minerals. Most of the silicates, carbonates, phosphates, sulfates, halides, and hydroxides have a vitreous luster.

Adamantine - Transparent to translucent minerals with a high refractive index yield an adamantine luster, meaning they display extraordinary brilliance and shine. Diamond.

Resinous - This is the luster of many yellow, dark orange, or brown minerals with moderately high refractive indices - honey like, but not necessarily the same color.

Silky - A silky luster is the result of a mineral having a fine fibrous structure. Minerals with a silky luster have optical properties similar to silk cloth.

Pearly - Describes a luster similar to the inside of a mollusk shell or shirt button. Many micas have a pearly luster, and some minerals with a pearly luster have an iridescent hue. Some minerals may exhibit a pearly luster on cleaved crystal surfaces parallel and below the reflecting surface of a mineral.

Greasy - Luster of a mineral that appears as if it were coated with grease.

Pitchy - Minerals with a tar-like appearence have a pitchy luster. Minerals with a pitchy luster are usually radioactive and have gone through the process of metamiction.

Waxy - A waxy luster describes a mineral that appears as if it were coated with a layer wax.

Dull - This luster defines minerals with poor reflective qualities, much like unglazed porcelain. Most minerals with a dull luster have a rough or porous surface.

Attached documents
Lustre sorting sheet.pdf
Grades taught
Gr 5

Molecular modelling of urea formation

Summary
Use molecule models to show the chemical reaction that makes urea from ammonia. Show the other molecules that other animals make to remove nitrogenous waste from their bodies.
Materials
  • molecular models (see resource): one ammonia molecule per student (one nitrogen three hydrogens three bonds) and one carbon dioxide per student pair (one carbon two oxygens four bonds)
Procedure

When we digest food, we absorb energy from it.
When proteins are broken down, we extract what we need from them (energy and building blocks for growth), but a toxic by-product containing nitrogen is made: ammonia (show molecule and point out nitrogen atom).
Our body has evolved to remove this toxin before it poisons us.
In our liver, it is converted to urea, which is 100,000 times less toxic.

Students use molecule models to show how urea is made from ammonia.
Each student receives an ammonia molecule, and each pair receives a carbon dioxide molecule.
Show them a urea molecule, and project the image.
Ask students to build a urea molecule with their partner from their ammonia molecules and the carbon dioxide molecule.
Ask them to use the rest of their atoms and bonds to make other molecule.
Help them figure out that the other molecule made with urea is H2O, or water.

Ask students to trace the nitrogen atoms through the excretory system.
Show a photo of a protein molecule, through which nitrogen comes into the body. (We need nitrogen for many important body processes.)

Urea circulates in our blood until it is taken out of the blood by the kidneys.

Mammals and amphibians excrete urea. (not monotremes, egg-laying mammals).
Other animals deal with nitrogenous waste in other ways.
Fish and aquatic animals simply excrete ammonia through their gills or skin. (Some frogs even switch from making ammonia to urea as they leave tadpole stage to adult frog.)
Birds, insects and many reptiles excrete uric acid. It can be excreted as a solid, or a paste - we know what bird poo texture is. Monotremes excrete uric acid. These animals started in eggs, where solid uric acid can be stored without harming the baby, and left behind when they hatch.

Grades taught
Gr 6

Kidney function

Summary
Use molecule models to build urea, then model how the kidney removes urea and wastes from the blood for excretion.
Materials

Materials in the activities

Procedure

Use molecular models to show how ammonia (too toxic to hold in the body for long) is converted to urea.
This happens in the liver.

Then model the mechanisms used in the kidney for removing urea and other wastes from the blood: filtering, then sorting by shape and diffusion.

Grades taught
Gr 6

Kidney sorting mechanisms

Summary
Model how the kidney removes wastes from the blood for excretion: sorting by size, diffusion and sorting by shape.
Procedure

Ask students to try each of the sorting activities (below), and to figure out how the materials are sorted in each case [by shape, size].
Review the different ways of sorting materials. (Optionally add in other ideas e.g. colour.)
Tell students that their kidney can remove poisons and other waste from our bodies by using sorting mechanisms.

Sorting by size
Make a mixture of marbles, gravel and sand.
Shake the mixture in a kitchen sieve and see what passes through the sieve.
The smallest items, which pass through the sieve (sand) represent the smaller blood molecules which pass through the kidney membrane into the kidney tubes (salts, water, urea, sugar, vitamins). The larger items held by the sieve (marbles and gravel) represent the blood cells and large protein molecules like albumin and antibodies, which stay in the blood.
Show image of kidney membrane that filters the blood, allowing smaller molecules into the kidney:
https://www.researchgate.net/profile/Jeffrey-Miner-3/publication/510761…
https://ars.els-cdn.com/content/image/3-s2.0-B9780123814623000732-f73-0…
The arrows point to the holes in the 'sieve'/filter between the capillary (blood) and urinary space of the kidney.
Diagram:
https://cdn.kastatic.org/ka-perseus-images/1b9aacb6315df5f730565e23d7bb…
Did you get small gravel stuck in the mesh? The kidney actively cleans its filter, to stop it clogging up.

Sorting by shape
Special molecules in the kidney tube walls only let some molecules through back into the blood.
If the small molecules have the right shape to fit, they can pass through the membrane.
Diagram: https://i.ytimg.com/vi/j-9z_p9yly0/maxresdefault.jpg
Like a lock and key mechanism.
Students find the lock which opens with their key. Their key is numbered. The locks each have a letter.
Draw a string of numbered boxes on the board. Students add the letter on the lock they open in the box with the same number as their key. The boxes spell out the name of the molecule gates in the kidney tube walls: "transport protein" (also called "carrier protein").

Moving from high to low concentration by diffusion
Drip food dye onto wet tissue on a flat surface, and watch as it slowly spreads out away from the concentrated drip, and into areas where there is no food dye.
This models diffusion (although it is too fast to be actual diffusion). Diffusion is how molecules move across membranes the same way, from high to low concentration.
Water and salts are moved back into the blood by this mechanism.

The kidney sorts blood molecules using these three above mechanisms.
Ask students how the sorting is happening in the activities - write up all responses.

Show diagram of kidney ducts and blood image, to show where three sorting mechanisms happen (by size, shape, and speed/concentration):
https://o.quizlet.com/4OkPEUeiopsNE6JxIos4Mw_b.jpg
or https://thumbs.dreamstime.com/b/nephron-functional-unit-kidney-minute-m…
First, in the rounded glomerulus, all the small molecules are filtered into the kidney, while large molecules and cells stay in the blood (sorting by size).
Then along the kidney tubes water, salts, sugars, vitamins and other nutrients are move through transport proteins back into the blood. Urea does not go back into the blood. (sorting by shape).
Many small molecules diffuse from high concentration to low concentration, which does not need any energy.
Sometimes energy is used to pump molecules up their concentration gradient e.g salt.
Urea mostly stays in the kidney tubes - it is not taken back into the blood, also other toxins. They flow to the bladder, to be later excreted.

As well as removing urea from our blood, the kidney regulates how much salt and water are returned to the blood, and how much is excreted. This keeps the blood chemistry exactly right, so that our organs can function properly.
The kidney filters an enormous amount of blood: every heartbeat, ¼ of your blood goes through the kidneys (1.2L of nearly 5L total)!

Notes

Note the nice parallel between the biology and chemistry topics at this curriculum grade level: the kidneys sort a heterogeneous mixture of blood components.

Grades taught
Gr 6
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