2 Cellular RespirationThe process by which the mitochondria breaks down glucose to produce ATP is called cellular respiration.C6H12O6 + 6O2 6CO2 + 6H2O + Energy
3 How much energy is actually present in food? Cellular RespirationHow much energy is actually present in food?1 gram of sugar glucose, when burned in the presence of oxygen, releases 3811 calories of heat energy!
4 “C” or Calorie used on food labels = 1000 calories (kilocalorie) Cellular Respirationcalorie- the amount of energy needed to raise the temperature of 1 gram of water 1 degree Celsius.“C” or Calorie used on food labels = 1000 calories (kilocalorie)
5 Cellular RespirationCells release the energy from glucose and other food components (they don’t burn it)
6 Cellular RespirationWhen the body has oxygen, aerobic respiration can take place and produce 36 ATP molecules.There are 3 stages of aerobic respiration:GlycolysisKrebs cycle (aka Citric Acid Cycle)Electron transport chain
8 GlycolysisGlycolysis takes place in the cytoplasm of the cell.
9 GlycolysisGlycolysis is the process where glucose is broken down in 2 pyruvic acid molecules. Pyruvic acid is a 3 carbon molecule.The net gain of ATP molecules in glycolysis is 2 ATP molecules.4-22
10 GlycolysisFollowing glycolysis, the pyruvic acid moves into the mitochondria.
11 The Krebs Cycle Citric Acid Cycle AKACitric Acid CycleThe Krebs cycle takes place in the MATRIX!Pyruvic acid enters the Krebs cycle and becomes broken down. As this occurs, 2 carbon dioxide molecules are released.In addition, 2 ATP molecules are released.Electron carriers such as FAD and NAD are used to pick up energized electrons and pass them to the ETC.
14 Krebs Cycle 2 ATP NADH + H pyruvic acid FADH2 ADP NAD CO2 FAD Electron carriersNADNADH + HpyruvicacidFADFADH2CO2FYI: Flavin adenine dinucleotide Nicotinamide adenine dinucleotide
15 The Electron Transport Chain The last step of respiration is the electron transport chain or ETC.It takes place in the inner membrane.In the presence of oxygen, the electron transport chain will produce 32 ATP molecules and water.The total of ATP molecules released from AEROBIC respiration is 36.36363636
16 Electron Transport Chain Electron carriers NADH and FADH2 release the Hydrogen ions across the membrane. This creates a concentration gradient.When oxygen enters the ETC, it becomes the final electron acceptor of the Hydrogens and creates H2O.As the hydrogen ions come back across the membrane, ADP is converted into ATP.Animation:
17 Electron Transport Chain Electron carriers NADH and FADH release the Hydrogen ions to proteins to cross the membrane. This creates a concentration gradient.When oxygen enters the ETC, it becomes the final electron acceptor of the Hydrogen ions and creates H2O.As the hydrogen ions come back across the membrane, ADP is converted into ATP.
20 Anaerobic Resp Fermentation AKAFermentationThere are times when cells are without oxygen for a short period of time. When this happens, anaerobic respiration is taking place.In anaerobic respiration, glycolysis takes place; then followed by one of two pathways:Lactic Acid Fermentation or Alcoholic Fermentation.Total ATP molecules released = 2.
21 Aerobic: presence of oxygen Anaerobic: absence of oxygen respirationAerobic
22 Types of Anaerobic Respiration When our cells run out of oxygen and begin fermentation, we build up lactic acid. That lactic acid build up in the muscle makes us feel a cramp and burning sensation.C6H12O6 ATP + lactic acidLactic Acid Fermentation
24 Types of Anaerobic Respiration Some fungi also undergo fermentation. They release ethyl alcohol and carbon dioxide.C6H12O6 ATP + CO2 + ethyl alcoholThis process is key for the yeast that create wine and other alcoholic beverages.Alcoholic Fermentation
25 Types of Anaerobic Respiration Yeast undergo this type of fermentation when making bread.
27 Comparing Photosynthesis and Respiration Glucose madeLight energy requiredATP broken down in 2nd phase of p.s.CO2 taken inO2 releasedNeeds waterTakes place in chloroplastTakes place in autotrophsGlucose broken downLight is not requiredEnergy created in ATPCO2 releasedO2 taken inWater releasedTakes place in mitochondriaTakes place in all organismsRequire use of ATP moleculesTake place in plantsNecessary to sustain all life on earth