The Phosphorus Cycle

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The Phosphorus Cycle
Start from the beginning
Make it Rain!
The Producers
The Consumers
The Decomposers
The Quiz
The Human Factor
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Why is Phosphorus Important?
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• DNA molecules are made from three smaller
  molecules
• Sugar
• Nitrogen base
• ???
• What is the 3rd molecule of DNA?

Fatty acid
Phosphate group
Mono-saccharide
No. Fatty acids are in lipids.
No. Monosaccharaides are in carbohydrates.
correct
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Why is Phosphorus Important?
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• ATP is a molecule needed by cells for _______.
• ATP stands for Adenosine Tri________?

Energy
Food
Releasing CO2
Hint What does the mitochondria create?
Hint What does the mitochondria create?
correct
prokaryote
Poly-saccharide
phosphate
Which choice looks like phosphorus?
Which choice looks like phosphorus?
correct
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Why is Phosphorus Important?
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• Which part of a cell is semi-permeable and allows
  some materials to enter/exit the cell?
• The cell membrane is made from a double layer of
  lipids called phospholipids. Which element is
  implied by the prefix phospho?

Mito-chondria
Cell membrane
Rough ER
Hint What does the mitochondria create?
Hint What does the mitochondria create?
correct
waste
waste
waste
Phosphorus
Potassium
Plutonium
glucose
glucose
Phosphocmon!
Phosphocmon!
correct
glucose
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Why is Phosphorus Important?
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• Our cells need phospholipids, DNA, and ATP. They
  each have phosphorus in them.
• So where does the phosphorus come from?
  Phosphorus come from rocks. Rocks are solid lumps
  of minerals, and some of those minerals are
  phosphorus. So when rocks crumble and erode,
  phosphorus is released from the rocks. The
  weather causes rocks to crumble. Wind, cold, and
  rain cause dust sized fragments of rocks to chip
  off, thus releasing phosphorus into the ground

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Make it Rain!
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• The weather causes phosphorus to be released from
  rocks. Click the cloud to make it rain.
• Small bits of phosphorus are released into the
  ecosystem due to the weather.
• Click the cloud to make it stop raining.
• Now that there is phosphorus in the soil, click
  on the land organism that can absorb it through
  their roots.

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P
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Snails dont have roots.
Roots think roots
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The Producers
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• Of course! Plants simply absorb the phosphorus
  through their roots. Click on the roots to
  proceed.
• Now that plants have phosphorus they can use it
  to make their DNA, ATP, and phospholipids.
• Click on the herbivore (primary consumer) in the
  diagram.

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P
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Decomposers feed on the dead. This plant is alive.
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The Consumers
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• Of course! The snail is an herbivore so it eats
  the plant. This is how animals get the phosphorus
  to make their DNA, ATP, and phospholipids.
• Phosphorus simply moves up the food chain. Which
  organism would likely eat snails?

P
P
P
Maybe accidentally, but cows are herbivores too.
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Wolves are hunters. I dont think they would hunt
snails.
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Up the Food Chain
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P
P
P

• The snail eats the plant
• The frog eats the snail
• Which would likely eat the frog?
• You got it. Phosphorus moves up the food chain.

Im an herbivore.
Im an herbivore.
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The Decomposers
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Like any organism, decomposers make waste. They
release their waste into the ecosystem. Some of
their waste even contains phosphorus.

• This whole thing started with crumbling
  rocksremember?
• Decomposers are organisms such as mushrooms and
  bacteria. They have DNA, ATP, and phospholipids
  also, so that means they need phosphorus too.
• Will decomposers feed on dead plants?
• You got it. Will they feed on dead snails?
• Were almost done.

Examine the picture if decomposers release
phosphorus into the soil, which organism can
reuse the phosphorus?
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P
I hope you see why its called the phosphorus
cycle.
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The plants
P
yes
no
The rocks
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P
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P
Rocks arent organisms
The snails
P
yes
no
What do snails eat?
P
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The Quiz
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• 1. Which molecule does not contain phosphorus?
• 2. How does phosphorus get into the soil in the
  first place?
• 3. Where do herbivores get phosphorus from?
• 4. Where do carnivores get phosphorus from?
• 5. Where do decomposers get phosphorus from?

DNA
ATP
Carbohydrate
Phospholipid
From rocks
From decomposers
From consumers
From producers
From rocks
From decomposers
From consumers
From producers
From rocks
From decomposers
From consumers
From producers
From any dead organism
From decomposers only
From consumers only
From producers only
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The Human Factor
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• Sadly, human actions are disrupting the
  phosphorus cycle. Humans, like this farmer,
  routinely add extra phosphorus to soil because
  phosphorus is a fertilizer. What do you think the
  extra phosphorus does for the farmers crops?

Kill weeds
Kill bugs
Stimulates growth
No. Weed killer kills weeds.
No. Pesticides kill bugs.
Yes, exactly!
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So if phosphorus helps crops grow, why is this
bad?
P
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Why is this Bad?
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• The extra phosphorus is intended to help crops
  grow better, but often the phosphorus is washed
  away into rivers, lakes, and ponds when it rains.

Make it rain
Rain Rain Go Away
The extra phosphorus got washed away and is
collecting in this pond. Since the phosphorus is
a fertilizer, it causes algae in the pond to grow
at an extreme rate. These extreme algae growths
are called algal blooms. As the algae
eventually die, the decaying process uses up the
oxygen in the pond, thus all the fish die. Once
the fish die, so does the rest of the ecosystem.
P
P
P
P
P
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P
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Wanna go for a swim?
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Wanna go for a swim?
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Wanna go for a swim?
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Is There Any Hope?
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• You can help stop this problem.
• Purchasing organic food supports farmers who do
  NOT use extra fertilizers.

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Is There Any Hope?
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• You can help stop this problem.
• Purchasing organic food supports farmers who do
  NOT use extra fertilizers.
• Not using fertilizers in your home garden
  prevents the spread of excess phosphorus.

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Is There Any Hope?
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• You can help stop this problem.
• Purchasing organic food supports farmers who do
  NOT use extra fertilizers.
• Not using fertilizers in your home garden
  prevents the spread of excess phosphorus.
• Often, produce sold at a farmers market is
  organic. The Beverly Hills Farmers Market is
  every Sunday from 9 a.m. to 1 p.m.

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The End
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