The process by which cells harvest the energy stored in food Cellular respiration 1
SAVING FOR A Rainy Day 2
Feel the Burn 3
How do living organisms fuel their actions? Cellular respiration: the big picture 4
ATP AdenineRibose3 Phosphate groups 5
ATP Energy Adenosine diphosphate (ADP) + PhosphateAdenosine triphosphate (ATP) Partially charged battery Fully charged battery 6
Glucose Glycolysis Krebs cycle Electron transport Fermentation (without oxygen) Alcohol or lactic acid Section 9-1 Chemical Pathways 7
Cellular Respiration: The Big Picture C 6 H 12 O 6 + 6O 2 6CO 2 + 6H 2 O + Energy (ATP) Glucose + Oxygen Carbon dioxide + Water + Energy (ATP) 8
Cellular Respiration: The big picture 9
Glucose Glycolysis Cytoplasm Pyruvic acid Electrons carried in NADH Krebs Cycle Electrons carried in NADH and FADH 2 Electron Transport Chain Mitochondrion Cellular Respiration: The Big Picture Mitochondrion Section
Three-Step Process Biggest ATP “payoff” (90%) occurs during the electron transport chain. 11
Cellular Respiration Section 9-2 Glucose (C 6 H ) + Oxygen (0 2 ) Glycolysis Krebs Cycle Electron Transport Chain Carbon Dioxide (CO 2 ) + Water (H 2 O) 12
Cellular Respiration Requires (1) fuel and (2) oxygen. 13
Cellular Respiration 14
In Humans… our cells can extract some of the energy stored in the bonds of the food molecules Energy Bonds Molecules 15
Aerobic Respiration – the video 16
Glycolysis is the universal energy- releasing pathway splitting (lysis) of sugar (glyco) all organisms on the planet single-celled organisms - provide all of the energy they need 17
Glycolysis is the universal energy- releasing pathway 18
Glycolysis Three of the ten steps yield energy High-energy electrons are transferred to NADH Net result: pyruvate ATP molecules NADH molecules 19
Glycolysis Glucose (6C) is broken down into 2 PGAL (Phosphoglyceraldehyde – 3 Carbon molecules) Cost: 2 ATP 20
Glycolysis 2 PGAL (3C) are converted to 2 pyruvates Result: 4 ATP, 2 NADH net ATP production = 2 ATP 21
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How Glycolysis Works Animation 23
Glycolysis: The Movie 24
The Fate of Pyruvate Yeast: pyruvic acid is decarboxylated and reduced by NADH to form a molecule of carbon dioxide and one of ethanol accounts for the bubbles and alcohol in, for examples, beer and champagne (alcoholic fermentation) process is energetically wasteful because so much of the free energy of glucose (~95%) remains in the alcohol (a good fuel!) Red blood cells and active muscles: pyruvic acid is reduced by NADH forming a molecule of lactic acid (lactic acid fermentation)NADH process is energetically wasteful because so much free energy remains in the lactic acid molecule Mitochondria: pyruvic acid is oxidized completely to form CO 2 & H 2 O (cellular respiration) ~ 40% of energy in original glucose molecule is trapped in molecules of ATP 25
Glycolysis is very inefficient 1. Pyruvate can be further metabolized to yield more energy 26
The mitochondrion 27
The Preparatory Phase to the Krebs Cycle 28
The Conversion of Pyruvate to Acetyl Co-A for Entry Into the Krebs Cycle 29 glycolysis (cytoplasm), pyruvic acid interior of mitochondrion
The Conversion of Pyruvate to Acetyl Co-A for Entry Into the Kreb's Cycle 2 NADH are generated 2 CO 2 are released 30
The Krebs Cycle extracts energy from sugar 31
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The Kreb’s Cycle extracts energy from sugar 6 NADH 2 FADH 2 2 ATP 4 CO 2 (to atmosphere) 33
The Krebs Cycle extracts energy from sugar 34
The Kreb’s Cycle extracts energy from sugar 35 Animation
Krebs: The Movie 36
Krebs: The Movie (Part 2) 37
the electron transport chain 38 2 key features of mitochondria
the electron transport chain 39 2 mitochondrial spaces higher concentrations of molecules in one area or the other
The “bag-within-a-bag” 40
Follow the Electrons, as We Did in Photosynthesis #2) This proton concentration gradient represents a significant source of potential energy! 41
Proton Gradients and Potential Energy 42
Electron Transport: The Movie 43
Electron Transport: The Movie (Part 2) 44
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Review of Cellular Respiration 46 Review Animation
Energy is obtained from a molecule of glucose in a stepwise fashion. 47
Plants have both chloroplasts and mitochondria. 48
Alternative Pathways to Energy 49 Rapid, strenuous exertion O 2 deficiency
Alternative Pathways to Energy 50 NAD + /FAD + halted back-up method for breaking down sugar lactic acid
Alternative Pathways to Energy Acquisition 51 Animation: Lactic Acid Fermentation
Alternative Pathways to Energy Acquisition 52 Yeast acetaldehyde produce alcohol only in the absence of oxygen
Alternative Pathways to Energy Acquisition 53 Animation: Alcoholic Fermentation
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anaerobic respiration 55
Cells can run on protein and fat as well as on glucose 56