Cellular Respiration

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Cellular Respiration How you get Energy
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Review Producers

• Producers get their energy from the sun.
• Producers convert this light energy into stored
  chemical energy (glucose).
• This process is called photosynthesis.

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Review Consumers

• Consumers get their energy from the producers.
• Consumers convert stored chemical energy
  (glucose) into usable chemical energy (ATP).
• This process is called cellular respiration.

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Cellular Respiration (aerobic)

• Cellular respiration is the process by which
  glucose (C6H12O6) is broken down to release
  energy for making ATP, another form of chemical
  energy.

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Aerobic Respiration Equation

• C6H12O6 6 O2 6 H2O 6 CO2 36 ATP

Does this look familiar?
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They are related!
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Why ATP? An analogy to money

• Glucose in our food is a great source of energy!
  (100 bill)
• However, individual cell processes may only
  require a small amount of energy (1 bill)
• Analogy most vending machines do not accept 100
  bills! We need a smaller form of currency for
  these processes.
• ATP (adenosine triphosphate) is this important
  cellular currency for life.
• ATP releases more appropriate amounts of energy
  for the individual cellular processes that
  require energy.
• (We will study this molecule in detail in our
  next activity!)

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The BIG Question is

• Do only animals respire?
• Or do plants respire too?
• Only plants perform photosynthesis
• Plants AND animals perform cellular respiration!
  
• (Can you explain why??)

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Site of Cellular Respiration

• Plant and animal cells contain mitochondria cell
  structures that transform chemical energy from
  glucose to ATP.

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Significant ATP Production

• Aerobic cellular respiration releases energy
  SLOWLY, using oxygen to convert ONE molecule of
  glucose to 36 ATP!

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Cellular Respiration (anaerobic)

• What happens when cells dont have enough oxygen?
• Some organisms live in an oxygen-free
  environment. How do they get their energy?

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Cellular Respiration (anaerobic)

• Anaerobic respiration is also called
  fermentation, or the process by which energy is
  released from glucose when oxygen is NOT
  available.
• This process allows organisms to continue to
  produce energy until oxygen is available.
• However, this process only releases 2 ATP per
  molecule of glucose.

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Alcoholic Fermentation

• Anaerobic way of converting energy for yeast and
  other microorganisms
• Glucose broken down to produce alcohol, CO2 and
  energy (ATP)
• C6H12O6 ? ethanol CO2 2 ATP
• EX baking bread with yeast
• fermenting wine beer

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Fermentation - Bread

• Source of sugar?
• DOUGH! (sugar and/or flour)
• Yeast use up the O2 and ferment sugar
• Produce CO2, which is trapped within
• tiny bubbles results in the dough rising
• Produce ethanol, which evaporates in the baking
  process

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Fermentation - Wine

• Source of sugar?
• GRAPES!
• Yeast use up the O2 and ferment sugar
• Produce CO2 (kept only in champagne)
• Produce ethanol ( alcohol varies based on sugar
  content of grapes and of fermentations)

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Fermentation - Beer

• Source of sugar?
• BARLEY!
• Yeast use up the O2 and ferment sugar
• Hops are added as a preservative
• and for added flavor
• Produce CO2 and ethanol also
• Various carbohydrates can be used to make alcohol
  including wheat, rice, and potatoes!

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Lactic Acid Fermentation

• Anaerobic way of converting energy in animal
  cells and some microorganisms
• Glucose broken down to produce lactic acid, CO2
  and energy (ATP)
• C6H12O6 ? lactic acid CO2 2 ATP
• EX muscle cells during strenuous exercise
• fermenting cheese, yogurt, sour cream

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Strenuous Exercise

• Lactic acid is produced by your muscle cells
  during rapid exercise when the body cannot supply
  enough O2 to tissues.
• Without enough O2, the body is NOT able to
  produce all of the ATP that is required.
• The buildup of lactic acid can cause painful
  burning in your muscles!

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Minimal ATP Production

• In the absence of oxygen, anaerobic respiration
  only releases 2 ATP for each molecule of glucose
  broken down.

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Comparing ATP Production

• First, your body breaks down glucose through
  aerobic respiration to produce 36 ATP per glucose
  molecule however, this is a slow process.
• When muscle cells cannot get enough O2 they break
  down glucose through lactic acid fermentation to
  produce 2 ATP per glucose
• Therefore, AEROBIC RESPIRATION is much more
  efficient in terms of ATP production
  36 ATP compared to 2 ATP!

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Aerobic Training

• Ex long runs, biking, swimming
• Can increase the size and number of mitochondria
  in muscle cells
• How would increasing mitochondria make you a
  better athlete?
• Can increase the delivery of O2 to muscles by
  improving the heart and lungs
• How would increasing O2 make you a better
  athlete?