Cellular Respiration!

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Cellular Respiration!
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• What do living things do with food?
• Produce materials that bodies need to grow
• Materials can be converted to energy
• C6H12O6 6O2 Enzymes 6CO2 6H2O energy

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How do living things release energy from food??

• Cellular respiration!
• Begins with glycolysis
• break down glucose ? pyruvic acid
• small amount energy released (ATP)

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Overview
No oxygen
Fermentation
Lactic Acid Alcoholic
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Glycolysis (in cytoplasm)

• Glucose (6C) split into
• 2 pyruvic acid (3C)
• Result 2 ATP 2 NADH
• 4ATP formed, 2 used ? net gain 2ATP

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• Who uses glycolysis?
• ALL organisms!!!
• Glycolysis does NOT require oxygen ? small amts
  of energy formed without O2
• As form ATP, available NAD decreases ? decreases
  ATP synthesis of glycolysis

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Fermentation!

• NADH converted to NAD
• Anaerobic respiration - does not require O2
• Two Types
• Lactic Acid
• Alcoholic

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What do these items have to do with fermentation?
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1. Lactic acid fermentation

• Pyruvic acid converted to lactic acid
• Lactic acid forming microorganisms used in making
  foods (Ex yogurt, cheese, sour cream)
• Lactic acid build up in muscles causes cramps

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1. Alcoholic fermentation

• Pyruvic acid converted to CO2 and ethyl alcohol
• Basis for wine and beer industry bread

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Efficiency of anaerobic respiration

• Glycolysis produces how many ATP molecules?
• TWO
• This is 2 energy in glucose
• Can any organisms survive on fermentation
  alone???

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Aerobic Respiration
No oxygen
Fermentation
Lactic Acid Alcoholic
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Aerobic respiration

• Energy in pyruvic acid released using oxygen
• Produces 20x more ATP than glycolysis!
• 2 major stages
• Krebs cycle
• Electron transport chain

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Where does respiration occur?

• Prokaryotes
• Respiration occurs in cytosol
• Anaerobic or aerobic?
• Eukaryotes
• Kreb cycle and ETC occur in mitochondria

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A little about the mitochondria

• 1. Pyruvic acid diffuses across membrane, enters
  matrix
• Matrix contains enzymes used in Krebs cycle
• 2. Pyruvic acid reacts with Coenzyme A to form
  acetyl CoA (produces 2 NADH)

Pyruvic Acid (C-C-C)
Coenzyme A
Acetyl CoA (C-C)
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Part I. The Krebs Cycle

• Overview energy molecules waste products
  formed as Acetyl CoA broken down
• Acetyl CoA forms citric acid
• CO2 molecules are released
• NADH, FADH2, ATP formed

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Energy Tally

• Glycolysis 2 ATP 2 NADH
• Conversion to 2 NADH Acetyl CoA
• Krebs cycle 2 ATP 6 NADH 2
  FADH2 12 energy molecules to next stage

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Part II. Electron Transport Chain

• Embedded in inner membrane of mitochondria
• Water released as waste byproduct
• High energy electrons converted to ATP
• Each NADH forms 3 ATP FADH2 forms 2 ATP

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Energy Conversion
The Rules NADH 3 ATP FADH2 2
ATP

• Glycolysis 2 NADH
• Conversion to 2 NADH Acetyl CoA
• Krebs cycle - 6 NADH 2 FADH2
• ETC

_____ ATP
_____ ATP
____ ATP ____ ATP
4 ATP TOTAL ATP Molecules ____
____ ATP?