Cellular Respiration

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Cellular Respiration
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Cellular Respiration

• L. respirare, to breathe
• (1) the oxygen-requiring stage in the breakdown
  release of energy from fuel molecules
• (2) the most prevalent efficient catabolic
  pathway for the production of ATP, in which
  oxygen is consumed as a reactant along with the
  organic fuel

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Got ATP?

• ATP Adenosine Triphosphate
• ALL cells must produce ATP to survive
• it is the energy currency of the cell

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• this ATP molecule allows work to be done by
  releasing energy with the breakage of the
  terminal high energy phosphate bond (between
  section C D in this diagram)

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Cellular Respiration

• an aerobic (oxygen-requiring) process that
  produces 36 ATPs
• MOST occurs in the mitochondriathe powerhouse
  of the cell

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Cellular Respiration

• Equation
• C6H12O6 (glucose) 6O2 ? 6CO2 6H2O energy
  (ATP)
• this is the overall net equationit is actually
  a complex reaction occurring in many steps
• note that it is the reverse of the net equation
  for photosynthesis
• produces CO2 that plants (autotrophs) need for
  photosynthesis

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Cellular Respiration

• 3 Steps
• Glycolysis
• Krebs Cycle
• Electron Transport Chain

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Glycolysis

• occurs in cytosol (outside the mitochondria)
• glucose is converted to pyruvate
• net gain of 2 ATPs 2 NADH
• ___
• - the coenzyme NAD is a key electron carrier in
  cellular respiration
• - another electron carrier, FADH, also plays a
  role

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Krebs Cycle

• occurs within the mitochondrial matrix
• pyruvate enters this multi-step cycle
• net gain of 2 ATPs, NADH FADH2

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Electron Transport Chain

• occurs within the inner membrane (cristae) of the
  mitochondria
• NADH FADH2 supply electrons
• produces of 32 ATPs
• oxygen (O2) is final electron acceptor in this
  reaction this is why we ( all animals)
  must have O2 to live!

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Fermentation

• a process much less efficient that cellular
  respiration which occurs in the absence of oxygen
  (an anaerobic process)
• produces a net gain of 2 ATPs (vs. 36 ATPs with
  respiration)
• occurs both in cells of organisms that live away
  from oxygen, and in cells that normally perform
  cellular respirationbut at times of insufficient
  O2 availability
• example lactic acid fermentation in human muscle
  cells during intense, anaerobic exercise (e.g.
  sprinting)

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Cellular Respiration Animation
from University of Rochester Medical Centers
Life Science Learning Center
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C\Documents and Settings\pchandleriii1\Desktop\Re
spiration presentation\respiration.html
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Chemical Pathways
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Cell Membrane
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Cellular Respiration Mini Quiz

• 1. Photosynthesis is to chloroplasts as cellular
  respiration is to
• a. chloroplasts
• b. mitochondria
• c. cytoplasm
• d. nuclei

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Cellular Respiration Mini Quiz

• 1. Photosynthesis is to chloroplasts as cellular
  respiration is to
• a. chloroplasts
• b. mitochondria
• c. cytoplasm
• d. nuclei

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Cellular Respiration Mini Quiz

• 2. The products of photosynthesis are the
• a. products of cellular respiration
• b. products of glycolysis
• c. reactants of cellular respiration
• d. reactants of fermentation

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Cellular Respiration Mini Quiz

• 2. The products of photosynthesis are the
• a. products of cellular respiration
• b. products of glycolysis
• c. reactants of cellular respiration
• d. reactants of fermentation

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Cellular Respiration Mini Quiz

• 3. Which of the following is the correct sequence
  of events in cellular respiration?
• a. glycolysis ? fermentation ? Krebs cycle
• b. Krebs cycle ? electron transport ? glycolysis
• c. glycolysis ? Krebs cycle ? electron transport
• d. Krebs cycle ? glycolysis ? electron transport

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Cellular Respiration Mini Quiz

• 3. Which of the following is the correct sequence
  of events in cellular respiration?
• a. glycolysis ? fermentation ? Krebs cycle
• b. Krebs cycle ? electron transport ? glycolysis
• c. glycolysis ? Krebs cycle ? electron transport
• d. Krebs cycle ? glycolysis ? electron transport

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Cellular Respiration Mini Quiz

• 4. Which of these processes takes place in the
  cytoplasm of a cell (NOT in the mitochondria)?
• a. glycolysis
• b. Krebs cycle
• c. electron transport
• d. ALL of the above

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Cellular Respiration Mini Quiz

• 4. Which of these processes takes place in the
  cytoplasm of a cell (NOT in the mitochondria)?
• a. glycolysis
• b. Krebs cycle
• c. electron transport
• d. ALL of the above

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Cellular Respiration Mini Quiz

• 5. What is the correct equation for
  cellular respiration?
• a. 6O2 C6H12O6 ? 6CO2 6H2O Energy
• b. 6O2 C6H12O6 Energy ? 6CO2 6H2O
• c. 6CO2 6H2O ? 6O2 C6H12O6 Energy
• d. 6CO2 6H2O Energy ? 6O2 C6H12O6

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Cellular Respiration Mini Quiz

• 5. What is the correct equation for
  cellular respiration?
• a. 6O2 C6H12O6 ? 6CO2 6H2O Energy
• b. 6O2 C6H12O6 Energy ? 6CO2 6H2O
• c. 6CO2 6H2O ? 6O2 C6H12O6 Energy
• d. 6CO2 6H2O Energy ? 6O2 C6H12O6