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					CELL RESPIRATION


 DR. MICHAEL C. POTTER
 PAUL VI CATHOLIC HIGH
        SCHOOL
          2006
 CELL RESPIRATION
GLUCOSE CATABOLISM

A.STAGE I: GLYCOLYSIS
B.STAGE II: PYRUVATE OXIDATION
C.STAGE III: KREBS CYCLE
D.STAGE IV: ELECTRON TRANSPORT
CELL RESPIRATION
CELL RESPIRATION
CELL RESPIRATION
  CELL RESPIRATION
A.GLYCOLYSIS: A process that occurs
   in the cytoplasm of every living cell

 1. Glucose Priming: This changes
    glucose into a molecule that can be
    “cleaved”.
    Requires 2 molecules of ATP
    Phosphofructokinase: commits
     glucose to glycolysis
CELL RESPIRATION
 CELL RESPIRATION
A.GLYCOLYSIS:
 2. Splitting & Rearrangement:
   Six carbon compound splits
    to (2) 3 carbon cmpds.
  Fructose 1,6, Diphosphate into
   (2) Glyceraldehyde 3 PO4
  “Substrate Level Phosphorylation”
    Making ATP (4 molecules/glucose)
CELL RESPIRATION
CELL RESPIRATION
GLYCOLYSIS:
 3. Oxidation: Removal of electrons
    (energy) & capturing in NADH
    from NAD+.

 4. ATP Generation: 4 reactions that
    convert G-3-PO4 to Pyruvate
    Generates 2 ATP per Pyruvate
CELL RESPIRATION
 CELL RESPIRATION
GLYCOLYSIS RESULTS IN:
 Glucose → 2 molecules Pyruvate
 2 molecules ADP → ATP for each
   molecule of pyruvate
 2 molecules NAD+ → NADH from
   oxidation of glyceraldehyde-3-PO4
CELL RESPIRATION
B. Oxidation of Pyruvate: Occurs
      in mitochondrion

  1. Aerobic conditions Pyruvate
    OXIDIZED to Acetyl CoA

  2. Anaerobic conditions result
    in FERMENTATION REACTIONS
CELL RESPIRATION
CELL RESPIRATION
CELL RESPIRATION
FERMENTATION REACTIONS:
 1.Lactic Acid Fermentation:
    Pyruvate REDUCED to Lactate
    No CO2 removal
    NADH → NAD+
 2. Alcohol Fermentation:
    Fungal (Yeast) Cells
    Pyruvate REDUCED to Alcohol
    CO2 Removed; NADH → NAD+
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CELL RESPIRATION
CELL RESPIRATION
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C. KREBS CYCLE:
 1. “Priming” Reactions
    Prepares the molecule for energy
     extraction
    Acetyl CoA (2C) joins oxaloacetate
     (4C) to form Citrate (6C)
    Citrate isomerizes to Isocitrate
CELL RESPIRATION
CELL RESPIRATION
C. KREBS CYCLE:
 2. “Energy Extraction”- oxidation
    reactions disassembling the
    molecule
      Decarboxylation Reactions
      Reduction NAD+→ NADH
      Reduction FAD+ → FADH2
    Regeneration oxaloacetate
CELL RESPIRATION
  CELL RESPIRATION
D. ELECTRON TRANSPORT
 System of REDOX reactions
 Series of membrane electron carriers
  Ubiquinone (quinone molecule)
  Cytochromes (contain Fe++)
  OXYGEN is final electron acceptor
  Water is final product (two H+)
      attach to oxygen
CELL RESPIRATION
 CELL RESPIRATION
D. ELECTRON TRANSPORT:
  The movement of electrons down
   the concentration gradient to
   O2 as the final acceptor releases
   protons (H+) to the intermembrane
   space
  Protons move thru ATP synthase
   making ATP from ADP (oxidative
   phosphorylation)
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CELL RESPIRATION
    Creating an H + Gradient


                    OUTER COMPARTMENT



 NADH




INNER COMPARTMENT
CELL RESPIRATION
         Making ATP:
      Chemiosmotic Model


         ATP

                    INNER
                 COMPARTMENT
ADP
 +
 Pi
  CELL RESPIRATION
ENERGY (ATP) YIELD per GLUCOSE
Glycolysis: 2ATP by substrate level
   phosphorylation
Oxidation Pyruvate: 2 NADH (3 ATP per)
Krebs Cycle: 6 NADH (3 ATP per)
               2 FADH2 (1-2 ATP per)
       2 ATP via GTP
Electron Transport: 32 ATP oxidative
   phosphorylation
CELL RESPIRATION
CYTOPLASM                      glucose

                                                               4   ATP
   2   ATP
                               Glycolysis
                        e- + H +                               (2 ATP net)
                  2 NADH                2 pyruvate

MITOCHONRIA                   e- + H+                 2 CO 2
        Overview of Aerobic
                  2 NADH
                              e- + H+
                  6 NADH
                  8                                   4 CO 2
           Respiration
                   Krebs
                   Cycle
                  2 FADH 2
                              e- + H+                          2   ATP



             e-                 Electron
                                Transfer                  32
                             Phosphorylation                         ATP



                                   H+         water

                               e- + oxygen
                                        Typical Energy Yield: 36 ATP


                                                                             Figure 8.3
                                                                             Page 135
 CELL RESPIRATION
Alternate Sources for Metabolism
 Glycolytic pathway thru ETS is
   “final common pathway”
 Other macromolecules can be utilized
     Lipids via β-oxidation
     Proteins via deamination (NH3)
     Nucleic Acids via deamination
 CELL RESPIRATION
                                         FOOD

                                       complex
         fats         glycogen                           proteins
      Alternative Energy Sources     carbohydrates

 fatty     glycerol                  simple sugars      amino acids
 acids
                                 glucose-6-phosphate   NH 3    carbon
                             GLYCOLYSIS                       backbones
                                            PGAL       urea

                                          pyruvate


                                         acetyl-CoA




                                           KREBS
                                           CYCLE


Figure 8.11
Page 145
 CELL RESPIRATION
Control of Glucose Catabolism
 Feedback inhibition
   Phosphofructokinase inhibited by:
    ATP levels
    Citrate levels
   Phosphofructokinase stimulated by
    ADP levels
    AMP levels
 CELL RESPIRATION
There is a mutualistic symbiotic
relationship between the products
of glycolysis and the requirements
for photosynthesis. This is an
interrelationship between the cell’s
mitochondria and chloroplast.
CELL RESPIRATION
           Processes Are Linked

sunlight energy
                      PHOTOSYNTHESIS



             water
               +                        sugar      oxygen
            carbon                     molecules
            dioxide

                         AEROBIC
                       RESPIRATION




                                                   In-text figure
                                                   Page 146
CELL RESPIRATION
CELL RESPIRATION
CELL RESPIRATION
CELL RESPIRATION
CELL RESPIRATION

				
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