Download Energy and Ecology Reading 11.5.12.w.answers

Homework assignment 11/5/12
Use the reading titled Energy Economics in Ecosystems from nature.com and your
own background knowledge to answer the questions below. Answer the questions in
full sentences. Please read the article first!
1. What is the “energy currency” of an ecosystem? The next section of the article
subtitled Energy Production goes on to explain how the energy currency is
created. Explain how the “currency” is created.
Carbon. Carbon is created from earth’s ultimate source of energy the sun. Plants
convert light energy into chemical energy (organic molecules), like sugars lipids and
proteins.
2. In the same subsection called Energy Production the author talks about “fossilized
sunlight.” What major point is the author trying to make when they use the term
“fossilized sunlight”?
Energy that comes from coal, natural gas and petroleum is actually from organisms
that captured the suns energy millions of years ago and stored it as carbon. Today we
release the energy from these carbon containing compounds through combustion
(burning coal, gas and oil).
3.
After you have read the subsection titled Energy Consumption look at the
chemical equations for Photosynthesis and Respiration. Describe the relationship
between the two. How are they related? Secondly, how do we as humans return
carbon to the atmosphere, so it can be used again by plants?
Photosynthesis starts with carbon dioxide and water and ends with sugar and oxygen.
Respiration starts with sugar and oxygen and ends with water and carbon dioxide.
Essentially the two equations compliment or support each other. The products of one
is the reactants of the other.
4.
In the subsection entitled Conservation of Energy: Balancing the Budget the first
sentence says light is converted to organic carbon compounds (sugars, fats, and
proteins). We’ve been saying this all along in our biology class. Now, read on and
answer the following: Why is primary production called “primary”? What happens to
most of the light energy that reaches earth from the sun?
Primary production is the amount of energy produced by plants. It is the biomass
directly produced from CO2 captured by plants.
Much of the light is reflected or absorbed and re-radiated back to space.
5. Look at your yard or street that you live on. Right now there is lots of carbon
floating around outside. Actually, lots of energy is there for the taking. People
may compost it and feed it to their garden next spring, burn it, or simply put in a
bag and have it hauled away. What am I referring to?
I’m referring to leaves! What great compost material and what a great source of
carbon. Compost your leaves over the winter and spring, and then add them to your
garden. You’re completing the carbon cycle and other nutrients cycles like the
nitrogen cycle.