Chapter 9: CELLULAR RESPIRATION

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Chapter 9: CELLULAR RESPIRATION Powered By Docstoc
					Chapter 9: CELLULAR
   RESPIRATION
   Please read “Summary: 9-1 Chemical
    Pathways” and underline the key phrases
    and/or sentences.
              Types of Reactions
   Endergonic - energy is absorbed during the
    reaction (energy enters)



                                  Products
              Reactants

   Exergonic - energy is released during the reaction
    (energy exits)


              Reactants

                                  Products
                     Why?
   Must convert macromolecules (glucose)
    into ATP in order for our bodies to be able
    to use the energy.

 Laundry Mat Example - $10 bill vs. quarters
 $10 bill is glucose
 Quarters are the ATP molecules
           Cellular Respiration



   Who does it?
    – ALL organisms!
    – Some do anaerobic, some do aerobic
      respiration, some do both

   Where does it take place?
    – In the cytoplasm (anaerobic steps) and
      mitochondria (aerobic steps)
          Overall Reaction for Cellular
                  Respiration


                              6 H2O        O

                                       H         H


                       O      6 CO2    O         O
                O                          C



Glucose         6 O2
                              Energy

                                           ATP
                  Overview
   Equation (you’ll need to memorize this!)

    C6H12O6 + 6O2  6CO2 + 6H2O + 36 ATP

 1 molecule of glucose produces 36 ATP
 How does the equation for cellular
  respiration relate to photosynthesis?

    Sunlight + 6CO2 + 6H2O  C6H12O6 + 6O2
                    Overview
   Breaks down food particles to create ATP

   3 stages:
     1. Glycolysis – anaerobic (doesn’t require O2)
     2. Citric acid OR Krebs cycle – aerobic (requires O2)
     3. Electron transport chain – aerobic
                               BIG PICTURE


              NADH


                     PYRUVIC ACID


GLUCOSE                                     NADH   Electron
          Glycolysis                Krebs
                                    Cycle          Transport
                                                   Chain
Cytoplasm
                                                               Mitochondrion
   Please do the “Cellular Respiration
    Overview” worksheet
Overview:

http://www.sumanasinc.com/webcontent/an
  imations/content/cellularrespiration.html
            OVERVIEW
      CELLULAR RESPIRATION

                2                           2                32

Glucose
                              O2
                              present
          Glycolysis                      Krebs           Electron
          (cytoplasm)
                                          cycle           transport
                        O2 not
                                        (mitochondria)    chain
                        present                          (mitochondria)




                    Fermentation (anaerobic)                              Alcohol
                          (cytoplasm)
                                                                          or lactic
                                                                          acid
Structure of a Mitochondrion
              1. Double membrane;
                  inner and outer
              2. Intermembrane Space –
                  space between inner
                  and outer membrane.
              3. Matrix – inside inner
                  membrane; location of
                  the Krebs Cycle
              4. Inner membrane; cristae
                  – finger like projections;
                  location of Electron
                  Transport Chain
   Please complete “Diagram of a
    Mitochondrion” worksheet
                  An Overview of Cellular
                       Respiration
                                      C6H12O6
                                         Glycolysis (2 net ATP’s)




 Aerobic Respiration                         Anaerobic Respiration
                                             (Fermentation) products
      Krebs Cycle (2 ATP’s)              Lactic Acid             Alcohol
                                         Fermentation            Fermentation

Electron Transport Chain (32 ATP’s)        Lactic acid     Alcohol + CO2

          CO2 + H2O                      Fermentation produces no more ATP
               Glycolysis

 Occurs in cytoplasm
 Breaks down glucose (6C) into two pyruvic
  acids (3C)
 Produces NADH, an electron carrier (goes
  to electron transport chain)
 Uses 2 ATP, but produces 4 ATP so a net
  gain of 2 ATP
 Pyruvic acid moves into mitochondria
    In the presence of oxygen:

 Next two stages of aerobic respiration can
  proceed: Krebs Cycle (Citric Acid Cycle)
  and the electron transport chain
 2 pyruvic acids produced in glycolysis
  (cytoplasm) move into the mitochondria
   Please read “Summary: 9-2 The Krebs
    Cycle and Electron Transport” and
    underline the key phrases and/or
    sentences.
Krebs Cycle
      Before entering Krebs
       cycle, pyruvic acid broken
       down into acetyl co-A
      Acetyl co-A enters Krebs
       cycle
      Makes 2 ATP, NADH,
       and CO2
      NADH moves into the
       electron transport chain
     Electron Transport Chain

 Takes place within the phospholipid bilayer of
  the inner membrane of the mitochondria –
  cristae
 NADH (created in glycolysis and Krebs cycle)
  pass electrons down electron transport chain
  (ETC)
 ETC pumps H+ ions out of the matrix, into the
  intermembrane space.
 ATP Synthase (channel protein in inner
  membrane) allows H+ to passively diffuse back
  into matrix, making ATP in the process.
Electron Transport Chain:

http://www.sumanasinc.com/webcontent/an
  imations/content/cellularrespiration.html
   Please do “Electron Transport Chain”
    worksheet
Energy Production at Each Step
                    Glucose C6H12O6



               Glycolysis in cytoplasm                  2 net ATP



          Pyruvic                     Pyruvic
          Acid                        Acid



                         Krebs                  2 ATP
                         Cycle



               Electron Transport Chain                 32 ATP


 TOTAL ATP PRODUCED FOR 1 MOLECULE OF GLUCOSE: 36!
           Putting it All Together
   Cells use many kinds of organic molecules
    as fuel for cellular respiration
     – Polysaccharides can be hydrolyzed
       (broken down) into monosaccharides and
       then converted into glucose for glycolysis
     – Proteins can be digested into amino acids,
       which are chemically altered and then
       used in the Krebs cycle
     – Fats are broken up and fed into glycolysis
       and the Krebs cycle
                  Food, such as
                  peanuts




Polysaccharides                          Fats             Proteins



   Sugars                     Glycerol     Fatty acids   Amino acids
                                                                       Amino
                                                                       groups




                           Pyruvic                                             ELECTRON
  Glucose         G3P                           Acetyl   KREBS
                            acid                                            TRANSPORT CHAIN
                                                 CoA     CYCLE
                                                                           AND CHEMIOSMOSIS
            GLYCOLYSIS
         Anaerobic Respiration
   Don’t forget, aerobic respiration (the Krebs
    cycle and the electron transport chain)
    require the presence of oxygen

   What happens when no oxygen is
    present?
    – Fermentation
         Anaerobic Respiration
 The only part of anaerobic respiration that
  produces ATP is glycolysis, processing
  after glycolysis does not produce any
  more ATP
 Only 2 ATP produced during anaerobic
  respiration
 2 types of anaerobic respiration:
1. Lactic acid fermentation
2. Alcohol fermentation
       Remember! – Glycolysis
 Occurs in cytoplasm
 Breaks down glucose (6C) into two pyruvic
  acids (3C)
 Produces NADH, an electron carrier
 Uses 2 ATP, but produces 4 ATP so a net
  gain of 2 ATP
       Lactic Acid Fermentation
 Pyruvic acid stays in cytoplasm
 Used by
    – human muscle cells at times of low oxygen
      (i.e. sprinting)
    – some bacteria and fungi to make cheese and
      yogurt.
   Is only a short term fix, can not continue
    indefinitely
        Lactic Acid Fermentation


Glucose  Pyruvic acid + NADH +  Lactic
 acid + NAD+

   NAH+ is reused in glycolysis
          Figure 9–4 Lactic Acid
              Fermentation



Glucose             Pyruvic acid   Lactic acid
   Please do “Glycolysis and Fermentation”
    worksheet
        Alcoholic Fermentation
 Pyruvic acid stays in cytoplasm
 Used by
    – yeast to make bread and alcohol
   Produces CO2 and ethyl alcohol (alcohol)

Glucose  Pyruvic Acid + NADH + 2 ATP
  Alcohol + CO2 + NAD+
Yeast Produce CO2 to Make
        Bread Rise
         Energy Production
 Aerobic Respiration =
36 ATP Total
 Anaerobic Respiration =
2 ATP Total
          Who Does What?
 Humans undergo aerobic respiration
  normally, but also can undergo anaerobic
  respiration when their muscle cells don’t
  get enough oxygen (i.e. sprinting)
 Yeast (single celled fungus) can undergo
  both aerobic and anaerobic respiration
  depending on whether oxygen is present
 Some bacteria are strictly anaerobic (ex: E.
  coli)
   Please do “Fermentation” worksheet
   Please do “Compare/Contrast Table”
    worksheet
   Please do “Cellular Respiration and
    Photosynthesis” worksheet
   Please do “Vocabulary Review” worksheet

				
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posted:7/27/2012
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