and Chemistry?

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and Chemistry?
Energy
Joules or calories
Joules or calories
Joules or calories
Joules or calories
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Evidence of Energy

• Motion
• Heat
• Light
• Sound

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Energy Units

• joule - energy exerted by a force of one Newton
  acting to move an object through a distance of
  one meter (SI unit)
• calorie - the amount of energy required to heat 1
  gram of water 1oC
• Calorie 1000 calories
• 1Joule 0.2390 cal

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How much is 1 Joule of energy?

• the energy required to lift a small apple one
  meter straight up.
• the energy released as heat by a quiet person,
  every hundredth of a second.
• the kinetic energy of an adult human moving a
  distance of about 6 inches every second.

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Types of Energy
Gravitational

• Chemical
• Heat
• Light
• Sound
• Electrical
• Magnetic
• Motion
• Nuclear

Chemical
Light
E
Thermal
Acoustic
Kinetic
Nuclear
Electromagnetic
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Energy Transformations
Gravitational
Chemical
Light
E
Thermal
Acoustic
Kinetic
Nuclear
Electromagnetic
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Energy Transformation
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Either or Energy

• Energy can be sorted into one of two categories
  
• either
• kinetic (the doing the work phase)
• or
• potential (the getting ready to do work or the
  stored phase)

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Energy examples
Potential Mechanical Energy and ?
Kinetic Mechanical Energy and ?
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Potential Energy Chemical energy stored in the
bonds of molecules Stored mechanical energy
stored in an object based on its position
relative to some reference state (i.e. a wound
springs, a stretched rubber band, a boulder
perched on the edge of a cliff) Nuclear
energy stored in nucleus of an atom Gravitational
energy stored based on relative position of
two objects
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Energy Transformation
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Food the ultimate potential energy

• C6H12O6 O2 ? CO2 H2O energy

ATP heat
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Do I need energy?
Where does energy come from?
What is energy?
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sun

• CO2 H2O energy ? C6H12O6 O2

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Tidal Marsh Food Web
2o Consumers
1o Consumers
Producers
Decomposers
Created by Michael J. Pidwirny, Ph.D.,
Department of Geography, Okanagan University
College
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Energy Flow in a Food Web
Sun Energy 100
Producers
1o Consumers
2o Consumers
90

• heat
• life needs
• motion

Decomposers
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The Energy Pyramid
Producers 100
1o Consumers 10
2o Consumers 1
3o Consumers 0.1
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• Our energy source aka food is primarily
  composed of
• Carbohydrates
• Fats
• Proteins

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• Carbohydrates are
• main source of energy
• broken up into simple sugars
• e.g. glucose and fructose
• digested mainly in the small intestines (begins
  in mouth)
• absorbed into the epithelial cells lining the
  small intestines

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• Fats
• have the highest energy/unit mass
• broken up into glycerol and fatty acids in the
  stomach and small intestines
• these smaller molecules contribute to cellular
  respiration entering either glycolysis or the
  Krebs cycle

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• Proteins are
• broken up into amino acids in the stomach and
  small intestines
• amino acids are then used to
• make new proteins
• contribute energy via glycolysis or the Krebs
  cycle

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Food Calories

• calorie the amount of energy needed to raise
• 1 gram of water by 1 oC
• a food calorie (C) 1000 calories
• chemists use the SI unit Joules
• 1 Joule 0.2390 cal

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Biomolecule Calories
Carbohydrate 4.4 calories/gm
Fat 9.0 calories/gm
Protein 4.4 calories/gm
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Daily Requirements
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A Typical Food Label
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Why the difference in Energy Content?
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Chemical Energy and Reactions

• The formation of glucose in plants is an
  endothermic reaction the resulting product has
  more energy than its reactants
• The breakdown of glucose is exothermic - the
  products have less energy than the reactants