Cellular Respiration

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Cellular Respiration

• South Carolina Standard
• B-3.2- The student will be able to summarize the
  basic aerobic and anaerobic processes of cellular
  respiration and interpret the chemical equation

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What is Cellular Respiration?

• It is the process of long term, slow
  production, of ATP for cellular energy
• Ultimate goal is to convert chemical energy in
  nutrients into chemical energy stored in ATP.
• ATP can then release energy for metabolic
  processes such as active transport, protein
  synthesis and muscle contraction

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Formula for Cellular Respiration 6O2 C6H12O6
gtgtgtgt 6H2O 6CO2

• The Reactants?
• The Products??
• Any food (organic) molecule (C,P,L) can be
  processed and broken down as a source of energy
  to produce ATP molecules

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Glycolysis

• First stage-takes place in the cytoplasm
• Glucose molecule is broken down into pyruvic acid
  and ATP
• Series of reactions using enzymes
• 4 molecules of ATP are produced for a net gain
  of 2 ATP.
• Products of Glycolysis are Pyruvic Acid, NADH,
  ATP

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Aerobic Respiration

• Most of the Pyruvic Acid produced during
  Glycolysis continues on the pathway of aerobic
  respiration- which takes place in the
  mitochondria
• It is chemically transformed and releases CO2,
  H2O and ATP
• Aerobic Respiration produces almost 20 times as
  much ATP as Glycolysis alone.

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Krebs Cycle or Citric Acid Cycle

• Krebs Cycle Pyruvic acid from glycolysis travels
  to mitochondria where it is broken down releasing
  Carbon Dioxide, water, 4 NADH, ATP and FADH2
• Also known as Citric acid Cycle because it is the
  first compound formed in this reaction.

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Krebs Cycle Cont..

• Carbon Dioxide is released as waste and
  becomes part of the atmosphere thus
  available for plants to use for
  photosynthesis.

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The Electron Transport Chain

• 2nd step of Aerobic Respiration.
• Series of chemical reactions that takes place in
  the inner membrane of the mitochondrion.
• H2O is produced as waste
• The ETC uses the high energy electrons from the
  Krebs Cycle to convert ADP to ATP.

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ETC cont..

• ATP synthase uses energy from H ions to convert
  ADP to ATP.
• End result of Cellular Respiration is 36 ATP-
  which is energy used for cellular metabolism

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Anaerobic Respiration-Fermentation

• Anaerobic process- Absence of O2
• Energy is released from food without Oxygen
• Not as efficient and results in a lot fewer ATP
• 2 types of fermentation
• Lactic Acid Fermentation
• Alcoholic Fermentation

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Lactic Acid Fermentation

• Pyruvic acid from glycolysis NADH is converted
  to Lactic Acid and NAD
• Produced in your muscles during rapid exercise
  when enough Oxygen is not reaching your
  tissues.
• Cells are rapidly producing ATP through this
  process.
• Form of Anaerobic Respiration

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Alcoholic Fermentation

• Occurs in yeasts and some bacterias
• Pyruvic acid from Glycolysis is combined with
  NADH to produce alcohol, CO2 and NAD
• This is what causes bread to rise.
• The alcohol produced -evaporates when the bread
  is baked.
• Form of anaerobic respiration

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How is this used?

• Alcoholic Fermentation is used to make beer,
  wine, bread and ethanol added to gasoline.
• Lactic Acid Fermentation plays an essential role
  in the manufacture of food products such as
  yogurt and cheese.

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Advantages and Disadvantages to Cellular
Respiration

• Advantages- it sustains energy production much
  longer than Glycolysis and fermentation.
  Produces a lot more ATP.
• Disadvantage- It is much slower than Glycolysis
  and fermentation.
• Glycolysis produces 1000s of ATP in
  milliseconds, but it quickly fills all available
  NAD molecules.

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Advantages and Disadvantages to Fermentation

• Advantage- Fermentation can release energy
  without oxygen.
• Disadvantage- Produces ATP for only 20-30 seconds
  and lactic acid causes painful side effects

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The End.