Lecture 3 Energy

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Lecture 3 - Energy

• From the Sun to your body

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Emc2

• What is the meaning of this equation?
• What does it have to do with Biology?

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Power of the Sun
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The Sun

• 110 times the diameter of the Earth
• Can accommodate 1.3 million Earths
• 100 million miles away from Earth
• Light takes 8 minutes to reach Earth
• 75 hydrogen and 25 helium
• Core temperature is 28 million oF
• Surface temperature is 10,000oF

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Answer Emc2
Power of the Sun
How long will our Sun last? Sun age about 5
billion years
Another 5 billion years
A tiny change in mass will give off enormous
amount of energy
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Harnessing energyBombing of Hiroshima
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Applications of Emc2

• Nuclear fission
• Splitting uranium
• Atomic bombs
• Nuclear power plant
• Nuclear fusion
• Hydrogen fusion
• Hydrogen bombs
• Solar furnace (Sun)

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Calorie Energy Unit

• Calorie is also known as kilocalorie
• Released heat energy that raises a kg of water by
  1oC
• Combustion in the presence of oxygen
• Measured using a Calorimeter

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Food is Energy
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Tour de France
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Tour de France

• Endurance race
• 2,000 mile cycling race
• Mountain terrain up to 10,000 feet
• 8,000 calories per day for Tour riders
• 3,000 calories per day for an average person

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From plant to animal
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Photosynthesis
In General Carbon Dioxide Water Sunlight
? Chemical energy Oxygen
Overall Equation n CO2 2n H2O light energy ?
(CH2O)n n O2
Glucose Synthesis 6 CO2 12 H2O light energy ?
C6H12O6 6 O2
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Photosynthesis
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Light
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Light
Glucose Synthesis 6 CO2 12 H2O light energy ?
C6H12O6 6 O2

• Competition for light,
• plants are not passive

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Water
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Water
Glucose Synthesis 6 CO2 12 H2O light energy ?
C6H12O6 6 O2

• Transpiration transport of water from roots to
  leaves
• Cells Xylem

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Energy and Ecosystems
Producers (autotrophs) organisms that can
capture solar radiation Consumers
(heterotrophs) organisms that rely on
producers for energy Food chains (linear) and
webs
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Energy and Ecosystems
Feeding relationships obey the 10 law
Energy pyramid Only 10 of the energy is
transferred to the next higher level
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Competition for plant energyGrazers of the
Acacia Tree
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Predators of the Acacia

• Dik-diks low browser
• Impalas mid browser
• Gerenuks high browser
• Giraffes tree-top browser

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Too much of a good thing
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Obesity in America

• 65 of Americans are overweight (2006)
• 1 in 3 Americans is obese
• 1 in 7 children is obese
• Mississippi leads the nation in obesity
• Causes of death in U.S. in 2000

1. Smoking 435,000 2. Obesity related
400,000
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Children and Obesity
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Obesity Trends Among U.S. AdultsBRFSS, 1990,
1998, 2007
(BMI ?30, or about 30 lbs. overweight for 54
person)
1998
1990
2007
No Data lt10 1014
1519 2024 2529
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http//www.cdc.gov/nccdphp/dnpa/obesity/trend/maps
/
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Health Hazards of Obesity
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Health Consequences of Obesity

• Heart diseases
• Diabetes
• Stroke
• Adult onset diabetes
• High cholesterol
• Osteoarthritis
• Certain types of cancer
• Shorter life span (6-20 years)

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Body Mass Index (BMI)
25.87
25.44
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Body Mass Index (BMI)

• Healthy BMI lt 25
• Overweight BMI 25-29
• Obese BMI 30

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Summary

• Sun ultimate source of energy
• Energy important for all biological processes
• Photosynthesis sunlight energy converted to
  chemical energy
• Plants provide most all organisms with energy
  (including you)
• Your energy balance (food vs. exercise) can have
  implications for your health

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For Next time Chemistry Read for next
time sections 5.3, 5.4 6.1 7.1, 7.2 19.4 20.4,
20.7