Cellular Respiration

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Cellular Respiration
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Respiration An Overview

• The process by which cells break down food
  sources such as glucose, fats, and protein and
  release their stored energy.
• Two main types
• Anaerobic no oxygen required
• Aerobic requiring oxygen
• Both forms produce energy storage molecules
  called ATP adenosine triphosphate.

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Anaerobic Processes

• No oxygen is required for these processes.
• Includes glycolysis, the breakdown of glucose,
  and fermentation.
• Some bacteria and yeast are examples of anaerobes.

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Glycolysis

• Occurs in the cytoplasm.
• Breaks down glucose into 2 molecules of pyruvate
  (3-carbon structures)
• 2 ATP molecules are formed.
• 2NADH energy shuttles are also formed.
• This pyruvate is further metabolized during
  fermentation

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Fermentation

• Pyruvate can be metabolized by
• Alcoholic fermentation
• Lactic acid fermentation
• AF produces ethyl alcohol and CO2 yeast can
  ferment apple juice to fill a balloon.
• LAF produces lactic acid. It can build up in
  muscles during strenuous exercise and cause
  burning and soreness.

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Aerobic Processes

• Requires oxygen.
• Most organisms are aerobes.
• Equation for Aerobic respiration
• C6H12O6 6O2 ? 6CO2 6H2O Energy
• Based on this equation Why do we breathe?

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The Mitochondria

• If O2 is present following glycolysis, pyruvate
  is modified and enters the mitochondria.
• Here food is broken down completely into CO2.
• Energy storage molecules like NADH and ATP are
  produced. This is why the mitochondria is called
  the power house of the cell.

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The Role of Oxygen

• Energy carriers like NADH drop off electrons and
  as they fall to oxygen during metabolism energy
  is stored in a payload of ATP.
• Oxygen picks up electrons and hydrogen ions to
  form water.

H2O
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ATP Adenosine Triphosphate

• ATP is the cells energy currency.
• Cellular work such as metabolism, transport, and
  movement is powered by the breakdown of ATP.
• ATP Structure
• Ribose a 5-carbon sugar
• Adenine a N-base
• 3 phosphate groups

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ATP / ADP Cycle

• ATP is constantly being used and remade in the
  cell.
• Energy is released or stored by breaking or
  making a phosphate bond.

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Summary of Cellular Respiration