Cellular Respiration

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Cellular Respiration

• The Energy in Food

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The Energy in Food

• Cellular Respiration A chemical process that
  uses oxygen to convert the chemical energy
  stored in foods (organic molecules) into another
  form of chemical energy.
• ATP Adenosine Triphosphate
• Cells in plants and animals use ATP as their main
  energy supply

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The Energy in Food

• Rapid Oxidation the release of
• chemical energy
  by
• burning
• This reaction is not controlled by enzymes
• Results consist of an uncontrolled energy release

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The Energy in Food

• Slow Oxidation the release of energy
• in a controlled
  fashion.
• Enzymes catalyze a sequence of events that cause
  covalent bonds to break one at a time.
• This is Metabolism!

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Photosynthesis / Cellular Respiration

• Recycle a common set of chemicals
• Water
• Carbon Dioxide
• Oxygen
• Glucose (Organic Compounds)

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ATP

• Phosphate part is most important

• Because of the negative charge on all the
  attached oxygens, there is a lot of potential
  energy in these bonds

• Removing the last phosphate group makes the
  molecule much happier (chemically stable)

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ATP to ADP
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Three Types of work that Cells Perform Review

• Chemical Work
• Building large molecules like proteins
• ATP provides energy for Dehydration Synthesis

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Three Types of work that Cells Perform Review

• Mechanical Work
• Muscle Contraction
• ATP causes change in shape of protein which then
  opens the door for Potassium (K) and Calcium (Ca)
  to cause the binding of Actin and Myosin.

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Three Types of work that Cells Perform Review

• Transport Work
• Pumping Ions across a membrane

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Respiration

• Organic compounds contained stored (potential)
  chemical energy in their bonds

• When that energy is released, cells can use it
  for metabolism

• Glucose (from glycogen stores) typically used
  first as the source of energy

• No glucose? Lipids next
• then amino acids/proteins (only in extreme
  cases- i.e. starvation)

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Respiration

• Controlled release of energy from organic
  compounds in cells to form
• Adenosine Triphosphate (ATP)

• Glycolysis is the first step in respiration

• Two types of respiration
• Aerobic (uses oxygen)
• Anaerobic (without oxygen)

• 2 types of anaerobic respiration
• Lactic Acid Fermentation (Humans / Mammals)
• Alcoholic Fermentation (yeast)

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Anaerobic RespirationLactic Acid Fermentation

• Normally in aerobic organisms that find
  themselves in a situation where oxygen is no
  longer availablewhy you breather harder when you
  work out

• Pyruvate converted to lactate (3-C), no CO2
  produced, no ATP produced

• When O2 becomes available, lactate converted back
  to pyruvate and then pushed through the aerobic
  pathway

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Anaerobic RespirationLactic Acid Fermentation

• DOES NOT MAKE YOU SORE
• NO ATP IS MADE SO IT DOES CAUSE FATIGUE

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Anaerobic RespirationAlcoholic Fermentation

• Occurs in yeast cells

• This is a normal situation for the yeast

• Pyruvate converted to ethanol (2-C) and CO2 is
  releasedboth waste products for the organism

• Bakers and brewers yeast allows bread to rise
  and beer to be carbonated (most commercial beer
  is forcibly carbonated as well)

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Fermentation in Microorganisms
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Oxygen and Cellular Respiration

• Breathing and Cellular Respiration
• Aerobic Process means it requires
• oxygen
• Cells Exchange
• Oxygen into the cell
• Carbon Dioxide out of the cell
• Body In your lungs Blood Exchange
• Oxygen (in)
• Carbon Dioxide (out)

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Cellular Respiration

• Chemical Formula
• Each glucose molecule yields 38 ATP molecules

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Reviewing the Mitochondria

• Found in almost all Eukaryotic Cells
• The Mitochondria structure is key to its role in
  cellular respiration
• Have their own DNA
• Have their own
• ribosomes

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Mitochondria

• Structure Made up of two membranes
• There is a space between the inner and the outer
  membrane
• Matrix the highly folded inner membrane
• enclosing a thick fluid
• Inside the inner membrane you find many of the
  enzymes involved in cellular respiration
• folds of the membrane allows a Large Surface
  Area for reactions to occur.
• MAXIMIZES the area for ATP production

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Cellular Respiration

• First
• Metabolism all chemical processes in a cell
• Metabolic Pathways Term given to cellular
• 
  respiration because it is
• made up
  of a series of
• reactions
  (thus the term
• pathways)
• Specific enzymes catalyzes each reactions in a
  pathways

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The Metabolic Pathways

• Three Steps or Stages
• Stage 1 Glycolysis Splitting Sugar
• First stage in breaking down glucose molecule
• Takes PLACE outside the mitochondria in the
  cytoplasm
• 2 ATP molecules are actually used to get things
  started.
• 2 ATPs split the glucose molecule in half.

Investment Stage

• Electrons are then transferred to a carrier
  molecule called NAD
• NAD then turn into NADH
• At this point 4 ATP are produced
• Now your up by 2 ATP

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The Metabolic Pathways

• Glycolysis (Payback Stage)
• Remember you used 2 ATPs to start
• Gained 4 (net gain)
• End Result are

• Two Pyruvic Acid Molecules

Glucose 2ATP 2 Pyruvic Acid
molecules
4ATP
Pyruvic Acid Molecules still hold most of the
energy of the original glucose molecules
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The Metabolic Pathways

• Stage 2 The Kreb Cycle
• Named after biologist Hans Krebs

Blame this guy
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The Metabolic Pathways

• The Kreb Cycle
• Finishes the breakdown of Pyruvic Acid molecules
  to CO2 - releasing more energy.
• Pyruvate loses a C as CO2, becomes acetyl-CoA
• Enzymes are dissolved in the Matrix inside the
  Matrix
• Called the Fluid Matrix

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The Metabolic Pathways
The Kreb Cycle

• Acetyl Co A joins a 4 Carbon Acceptor molecule
• Produces 2 CO2 1 ATP per Acetyl CoA
• NADH and FADH2 (another electron carrier) trap
  most of the energy
• At the end you are left with a 4 carbon acceptor
  molecule
• So the cycle can continue

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The Metabolic Pathways
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The Metabolic Pathways

• The Kreb Cycle
• Results
• Glycolysis produces 2 Pyruvic Acid molecules from
  1 glucose molecule
• Each Pyruvic Acid molecule makes 1 Acetyl CoA
• Cycle turns 2 TIMES
• Producing 4 CO2 2ATPs

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The Metabolic Pathways

• Electron Transport Chain ATP Synthase Action
• First (carrier molecules) NADH transfers
  electrons from the original glucose molecule to
  an electron transport chain.
• Remember e move to carriers that attract them
  more strongly
• This is why they move from carrier to carrier
• One carrier attracts them more than the one
  carrying moving the e to the inner mitochondria
  
• Finally being pulled by oxygen at the end of the
  chain.
• 2 H? combines with oxygen forming H2O

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The Metabolic PathwaysElectron Transport Chain
ATP Synthase Action
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The Metabolic PathwaysElectron Transport Chain
ATP Synthase Action

• ATP Synthase Protein structures inside the
  mitochondria that receives the H? uses that flow
  to convert ADP into ATP.
• Can make up to 34 ATPs

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The Final Count

• Glycolysis 2 ATP
• Kreb Cycle 2 ATP
• Electron Transport Chain 34 ATP
• Maximum ATP for 1 Glucose Molecule 38
• Notice most ATP is made after Glycolysis and Kreb
  Cycle which are anaerobic (without O2)

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Aerobic respiration
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Types of Respiration





Aerobic Respiration
Anaerobic Respiration
Occurs in the absence of Oxygen
Occurs in presence of Oxygen
Occurs in the cells cytoplasm
Occurs in the cells mitochondria
Yields small amount of ATP (2 molecules) per
molecule of glucose
Yields large amount of ATP (38 molecules) per
molecule of glucose
Does not involve fermentation
Involves fermentation of pyruvate to lactate in
muscles/CO2 ethanol in plant yeast
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Comparison between Aerobic Anaerobic
Respiration -Animals