UCSD-TV: Molecules for the Media

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Study Guide

The Sun’s energy is the source of most of the energy on Earth. How much energy from the Sun enters the Earth System? The outer atmosphere of the Earth receives, on average,

1,366 watts of energy from the Sun per square meter.

Not all of the Sun’s energy striking the outer atmosphere continues to the Earth’s surface. Compare the amount of energy from the Sun with how much we use as a society.

What happens to the energy that gets to Earth? Answer

The amount of energy reflected by the Earth is important because too much reflection and we cool down, but too little reflection and we heat up. Albedo is the term scientists use to describe how much a surface reflects incoming energy. Each planet, like our Earth, has an albedo number.

Want to learn more? Investigate Albedo

(Scroll down to “Albedo” and then play with the numbers in the “What If?” interactive chart by adjusting the amount of energy coming from the Sun versus the Earth’s albedo (reflectivity). Be sure to try out the different scenarios suggested below the chart.)

What are the forms of Energy?

To find out, click on the computer in this picture. Scroll down to the Table of Contents and click on the different forms of energy. Watch the video clip of Dr. Robert Cattolica discussing biomass as a renewable energy source--from 6 minutes 27 seconds to 14 minutes 6 seconds.

How does the amount of heat energy coming from the Earth’s core compare to the amount of solar radiation striking the Earth?

To find out, go to: Energy Quest. For information on the thermal energy in the core, visit chapter 11 (access the Table of Contents by clicking on the computer).

What forms of energy come from the Sun?

We all know that the Sun gives us visible light, photons. It also gives off invisible light energies, which are also photons, across the entire electromagnetic spectrum that includes gamma rays, X-Rays, ultraviolet, infrared, microwaves, and radio waves. It does not seem to be broadcasting Hip Hop or Heavy Metal music but the rays the Sun emits can have exciting and dangerous consequences. X-rays and gamma rays could cause birth defects if our atmosphere did not protect us from them. The UV (ultraviolet) rays cause sunburn that may lead to skin cancer. The microwaves that the Sun sends us will never bake a potato here on Earth but the heat from the photons absorbed by the Earth’s surface occasionally fries an egg on asphalt roads in New York during the summer.

Investigate the Electromagnetic Spectrum.

Hear the Sun sing or watch it boil.

Watch a recent video of the sun.

How is Energy from the Sun absorbed?

Some of the energy from the sun that is not reflected by the atmosphere, or off the surface of the Earth, is absorbed. Photons striking the Earth warm the land and water and create weather and seasonal changes. Some of the photons are absorbed by plants during photosynthesis when carbon is bonded to form sugars.

The sun provides the energy for life and drives the Carbon Cycle.

Where is carbon found? What are the different physical and chemical forms of carbon in the atmosphere, oceans, biomass and fossil fuels (carbon reservoirs)?

How does the carbon cycle through those reservoirs and how are the Earth’s internal and external sources of energy involved in that?

Answer

How long does carbon stay in each of the various reservoirs?

Play the Carbon Cycle Game.

Energy and Photosynthesis

Carbon has four electrons in its outer shell. Carbon forms single, double and triple bonds with another carbon atom by sharing electrons in a covalent bond. Carbon also forms single, double and triple bonds with different elements such as hydrogen and oxygen.

Take a look at the electrons of a carbon atom.

Find out about the special features of carbon bonding that make life possible. Visit:

Edinformatics or Wikipedia

Learn more advanced organic chemistry.

Investigate the carbon atom numbering system in carbon compounds.

Plants use the Sun’s energy to combine carbon dioxide (CO2) with water (H2O) to form sugar (C6H12O6) and give off the oxygen (O2) that we breathe. Plants chemically change the sugar into fat and starch for storage.

How do plants convert the energy from the sun into carbon compounds: sugar, oil and starch?

To find the answers, investigate Photosynthesis:

Chloroplast Diagram and Photosynthesis Information

How do plants and animals break down carbon compounds to use them to power life processes?

Investigate Respiration

Suggest an experiment to compare the amount of photosynthesis taking place in a leafy plant with photosynthesis in green algae.
Hints:

What gases could you measure?

Could you measure the plant weight or the growth in length, height or number of leaves?

What is the Greenhouse Effect?

Most of the light that reaches the Earth from the Sun is in the visible light wavelengths, but the Earth is cooler so the light radiating from it is in a longer wavelength in the infrared.

Carbon dioxide (CO2) and methane (CH3) stop infrared light. They let the visible light from the Sun in but stop the infrared radiating from the Earth from leaving.

More CO2 and CH3 in the atmosphere means more of the Earth’s heat is trapped. But the Sun’s visible light continues to get through.

Find out more about the greenhouse effect and atmospheric chemistry.

Can you suggest solutions to decrease the build up of Carbon Dioxide (CO2) and Methane (CH3) in the atmosphere?

What are the different types of energy used by society and where do they come from?

The people in developing nations often burn dung from animals or wood for cooking and heating. Dr. Steven Briggs suggests that the dung should be used as fertilizer instead, because burning it pollutes the air and causes respiratory problems for people. People also strip the land of plants in their search for wood. Among the developed nations electricity, gas, coal and oil are most commonly used as energy sources.

Turn on a light switch and a dark room is washed in bright light. Electricity comes from many sources: water cascading over hydroelectric dams; giant windmills; solar panels; nuclear power plants, and coal powered steam turbines. Toss wet clothes into the drier and you might be using gas jets to heat the air that dries the clothes. We use both electricity and gas to cook our food. It is difficult to store electricity. Liquid and gas fuels - fossil fuels - are more easily stored for later use.

We use fossil fuels to make everything from gasoline to plastic toys. Carbon-based fossil fuels—oil, coal, oil shale, natural gas, etc.—originated in plants and animals. When plants and animals are buried after they die by sediments carried by water, the carbon compounds that they contained change and pool together. Sometimes they stay suspended as tiny isolated drops when the other minerals in the sediments harden around them to form shale. Shale that contains oil is called oil shale. Over many millions of years the oil transforms into the black oil we are familiar with and into natural gas. Coal formed in similar way.

Find out more about how fossil fuels are formed:

U.S. Department of Energy
Energy Quest

How do fossil fuels run machines?

Investigate an Internal Combustion Engine

What is Renewable Energy?

Fossil fuels will eventually be used up. We have to find cleaner renewable energy sources.

View the video clip of Dr. Justin Stege of Verenium Corporation discussing the ecological, social and economic costs of energy use and production, and how termites use bacteria to break down biomass (wood) for energy—from 34 minutes to 43 minutes and 2 seconds.

Investigate Renewable Energy

Investigate the range of renewable energy sources

What are Carbon Based Biofuels and how are they produced?

Fossil fuels are running out. Using fossil fuels as an energy source has a high ecological cost and leaves behind a large carbon footprint. There is active research into cleaner burning renewable fuels produced from biomass (waste), plants and even algae.

Find out why one group of explorers decided to produce and use their own biofuels and other environmental solutions to a large carbon footprint.

Why were they defending the type of vehicles they used?

Ethanol (empirical formula: C2H6O)

Ethanol is produced from corn, other grains, fruit, sugarcane, and potatoes. Ethanol is the alcohol in alcoholic drinks. Bacteria and yeast produce it because they inefficiently break down sugars using only glycolysis and not the complete respiration process. Ethanol is produced commercially and added to gasoline as a cleaner burning fuel.

Dr. Steven Briggs from the University of California, San Diego describes how ethanol has “low energy density” getting only 70% of the mileage as compared to pure gasoline.

Watch the video clip of Dr. Briggs—from 14 minutes and 31 seconds to 24 minutes and 14 seconds.

According to Dr. Greg Mitchell from Scripps Institution of Oceanography, ethanol can also be produced from algae and there are many advantages over corn:

Corn is a food crop so using it as a fuel would decrease the world food supply.
Algae grows faster, so many crops are harvested in a shorter time.
Algae can be grown on marginal land in brackish water or waste water, so it does not compete for scarce fresh water resources.
50% of the algae is used for fuel and the rest can be used as animal feed.
Algae can be used to produce fats for biodiesel production or starch for ethanol production.

There are also problems with algae as biofuel:

“Corn-to-ethanol is a mature technology,” meaning that ethanol is already produced from corn on a commercial scale.
Research is necessary to scale up algae-to-ethanol production.

Watch the video clip of Dr. Mitchell—from 24 minutes and 39 seconds to 33 minutes and 36 seconds.

Algae growing among cattails and water lilies
Photo by Joseph Wellhouse

	Study Guide \| Explore This Topic \| Meet the Scientist Links & Resources \| Teacher Resources \| Overview Study Guide The Sun’s energy is the source of most of the energy on Earth. How much energy from the Sun enters the Earth System? The outer atmosphere of the Earth receives, on average, 1,366 watts of energy from the Sun per square meter. Not all of the Sun’s energy striking the outer atmosphere continues to the Earth’s surface. Compare the amount of energy from the Sun with how much we use as a society. What happens to the energy that gets to Earth? Answer The amount of energy reflected by the Earth is important because too much reflection and we cool down, but too little reflection and we heat up. Albedo is the term scientists use to describe how much a surface reflects incoming energy. Each planet, like our Earth, has an albedo number. Want to learn more? Investigate Albedo (Scroll down to “Albedo” and then play with the numbers in the “What If?” interactive chart by adjusting the amount of energy coming from the Sun versus the Earth’s albedo (reflectivity). Be sure to try out the different scenarios suggested below the chart.) What are the forms of Energy? To find out, click on the computer in this picture. Scroll down to the Table of Contents and click on the different forms of energy. Watch the video clip of Dr. Robert Cattolica discussing biomass as a renewable energy source--from 6 minutes 27 seconds to 14 minutes 6 seconds. How does the amount of heat energy coming from the Earth’s core compare to the amount of solar radiation striking the Earth? To find out, go to: Energy Quest. For information on the thermal energy in the core, visit chapter 11 (access the Table of Contents by clicking on the computer). What forms of energy come from the Sun? We all know that the Sun gives us visible light, photons. It also gives off invisible light energies, which are also photons, across the entire electromagnetic spectrum that includes gamma rays, X-Rays, ultraviolet, infrared, microwaves, and radio waves. It does not seem to be broadcasting Hip Hop or Heavy Metal music but the rays the Sun emits can have exciting and dangerous consequences. X-rays and gamma rays could cause birth defects if our atmosphere did not protect us from them. The UV (ultraviolet) rays cause sunburn that may lead to skin cancer. The microwaves that the Sun sends us will never bake a potato here on Earth but the heat from the photons absorbed by the Earth’s surface occasionally fries an egg on asphalt roads in New York during the summer. Investigate the Electromagnetic Spectrum. Hear the Sun sing or watch it boil. Watch a recent video of the sun. How is Energy from the Sun absorbed? Some of the energy from the sun that is not reflected by the atmosphere, or off the surface of the Earth, is absorbed. Photons striking the Earth warm the land and water and create weather and seasonal changes. Some of the photons are absorbed by plants during photosynthesis when carbon is bonded to form sugars. The sun provides the energy for life and drives the Carbon Cycle. Where is carbon found? What are the different physical and chemical forms of carbon in the atmosphere, oceans, biomass and fossil fuels (carbon reservoirs)? How does the carbon cycle through those reservoirs and how are the Earth’s internal and external sources of energy involved in that? Answer How long does carbon stay in each of the various reservoirs? Play the Carbon Cycle Game. Energy and Photosynthesis Carbon has four electrons in its outer shell. Carbon forms single, double and triple bonds with another carbon atom by sharing electrons in a covalent bond. Carbon also forms single, double and triple bonds with different elements such as hydrogen and oxygen. Take a look at the electrons of a carbon atom. Find out about the special features of carbon bonding that make life possible. Visit: Edinformatics or Wikipedia Learn more advanced organic chemistry. Investigate the carbon atom numbering system in carbon compounds. Plants use the Sun’s energy to combine carbon dioxide (CO2) with water (H2O) to form sugar (C6H12O6) and give off the oxygen (O2) that we breathe. Plants chemically change the sugar into fat and starch for storage. How do plants convert the energy from the sun into carbon compounds: sugar, oil and starch? To find the answers, investigate Photosynthesis: Chloroplast Diagram and Photosynthesis Information How do plants and animals break down carbon compounds to use them to power life processes? Investigate Respiration Suggest an experiment to compare the amount of photosynthesis taking place in a leafy plant with photosynthesis in green algae. Hints: What gases could you measure? Could you measure the plant weight or the growth in length, height or number of leaves? What is the Greenhouse Effect? Most of the light that reaches the Earth from the Sun is in the visible light wavelengths, but the Earth is cooler so the light radiating from it is in a longer wavelength in the infrared. Carbon dioxide (CO2) and methane (CH3) stop infrared light. They let the visible light from the Sun in but stop the infrared radiating from the Earth from leaving. More CO2 and CH3 in the atmosphere means more of the Earth’s heat is trapped. But the Sun’s visible light continues to get through. Find out more about the greenhouse effect and atmospheric chemistry. Can you suggest solutions to decrease the build up of Carbon Dioxide (CO2) and Methane (CH3) in the atmosphere? What are the different types of energy used by society and where do they come from? The people in developing nations often burn dung from animals or wood for cooking and heating. Dr. Steven Briggs suggests that the dung should be used as fertilizer instead, because burning it pollutes the air and causes respiratory problems for people. People also strip the land of plants in their search for wood. Among the developed nations electricity, gas, coal and oil are most commonly used as energy sources. Turn on a light switch and a dark room is washed in bright light. Electricity comes from many sources: water cascading over hydroelectric dams; giant windmills; solar panels; nuclear power plants, and coal powered steam turbines. Toss wet clothes into the drier and you might be using gas jets to heat the air that dries the clothes. We use both electricity and gas to cook our food. It is difficult to store electricity. Liquid and gas fuels - fossil fuels - are more easily stored for later use. We use fossil fuels to make everything from gasoline to plastic toys. Carbon-based fossil fuels—oil, coal, oil shale, natural gas, etc.—originated in plants and animals. When plants and animals are buried after they die by sediments carried by water, the carbon compounds that they contained change and pool together. Sometimes they stay suspended as tiny isolated drops when the other minerals in the sediments harden around them to form shale. Shale that contains oil is called oil shale. Over many millions of years the oil transforms into the black oil we are familiar with and into natural gas. Coal formed in similar way. Find out more about how fossil fuels are formed: U.S. Department of Energy Energy Quest How do fossil fuels run machines? Investigate an Internal Combustion Engine What is Renewable Energy? Fossil fuels will eventually be used up. We have to find cleaner renewable energy sources. View the video clip of Dr. Justin Stege of Verenium Corporation discussing the ecological, social and economic costs of energy use and production, and how termites use bacteria to break down biomass (wood) for energy—from 34 minutes to 43 minutes and 2 seconds. Investigate Renewable Energy Investigate the range of renewable energy sources What are Carbon Based Biofuels and how are they produced? Fossil fuels are running out. Using fossil fuels as an energy source has a high ecological cost and leaves behind a large carbon footprint. There is active research into cleaner burning renewable fuels produced from biomass (waste), plants and even algae. Find out why one group of explorers decided to produce and use their own biofuels and other environmental solutions to a large carbon footprint. Why were they defending the type of vehicles they used? Ethanol (empirical formula: C2H6O) Ethanol is produced from corn, other grains, fruit, sugarcane, and potatoes. Ethanol is the alcohol in alcoholic drinks. Bacteria and yeast produce it because they inefficiently break down sugars using only glycolysis and not the complete respiration process. Ethanol is produced commercially and added to gasoline as a cleaner burning fuel. Dr. Steven Briggs from the University of California, San Diego describes how ethanol has “low energy density” getting only 70% of the mileage as compared to pure gasoline. Watch the video clip of Dr. Briggs—from 14 minutes and 31 seconds to 24 minutes and 14 seconds. According to Dr. Greg Mitchell from Scripps Institution of Oceanography, ethanol can also be produced from algae and there are many advantages over corn: Corn is a food crop so using it as a fuel would decrease the world food supply. Algae grows faster, so many crops are harvested in a shorter time. Algae can be grown on marginal land in brackish water or waste water, so it does not compete for scarce fresh water resources. 50% of the algae is used for fuel and the rest can be used as animal feed. Algae can be used to produce fats for biodiesel production or starch for ethanol production. There are also problems with algae as biofuel: “Corn-to-ethanol is a mature technology,” meaning that ethanol is already produced from corn on a commercial scale. Research is necessary to scale up algae-to-ethanol production. Watch the video clip of Dr. Mitchell—from 24 minutes and 39 seconds to 33 minutes and 36 seconds. Algae growing among cattails and water lilies Photo by Joseph Wellhouse ©2010 Regents of the University of California. Terms and Conditions of Use.		Watch Now (English) (57 minutes) Spanish Version For specific clips, scroll ahead to certain segments in the video. For example, if the segment is (6m:27s—14m:06s), then the clip begins at 6 minutes and 27 seconds and ends at 14 minutes and 6 seconds. Introduction (1m:55s—6m:23s) Renewable Fuel from Biomass Waste (6m:27s—14m:06s) High Energy BioGas/Diesel (14m:31s—24m:14s) Algae Biofuel (24m:39s—33m:36s) Enzyme Discovery and Evolution for Commercial Biofuels Applications (34m:00s—43m:02s)