2 Think of Photosynthesis like baking a cake. The plant takes the raw materials (CO2 & H2O), puts them together using energy (heat), & synthesize the cake.In order to get the energy out of the cake, the plant & us must ingest it (eat), digest it (break it down into its monomers) & then we must “burn it” to release the energy stored in the bonds of the cake.THIS IS RESPIRATION
3 How do we get the energy out of the food that we have consumed?
4 Cellular Respiration Nutrient = Glucose Chemical Energy = ATP Is the process by which organisms obtain the energy they need by releasing the chemical energy stored in nutrients and transferring that energy into ATPNutrient = GlucoseChemical Energy = ATP
5 Occurs in the Mitochondria of Eukaryotic organisms Respiration occurs on the cristaeDoes this sound familiar?
6 Two Types of Respiration Aerobic Respiration – needs oxygen to release the energy in foodC6H12O6 + 6O2 6CO2 + 6 H2O + 36 ATPAnaerobic Respiration – can release the energy from food without the need of oxygen. (Some bacteria & yeast)C6H12O6 2 CO2 + 2 Ethanol + 2 ATP = alcoholic fermentationC6H12O6 2 Lactic Acid + 2 ATP = lactic acid fermentation
7 Anaerobic Respiration Also known as fermentationOccurs in the cytoplasm of yeast, some bacterial cellsSince the organisms are very small and their needs are simple, they do not need much ATP
8 Anaerobic Respiration occurs in two steps GlycolysisGlucose (6 Carbons) is broken down into 2 Pyruvic (3 Carbons each) acid molecules + 2 ATP (activation energy)Produces 4 ATP, netting 2 ATP2 ATP
9 Fermentation Both forms will not produce any more ATP molecules The 2 Pyruvic Acids will break down into:1. Alcohol + CO2 (yeast and some bacteria)2. Lactic Acid (bacteria, us – more later)Both forms will not produce any more ATP molecules
10 Uses for Fermentation Yeast & some bacteria Used in baking, wine making and brewing industryBacteriaLactic acid production is used in cheese processing, buttermilk, sour cream, yogurt, sauerkraut, pickles. The souring of dairy products is actually the production of lactic acid by anaerobic bacteria
11 Aerobic RespirationOccurs in the mitochondriaYields more ATP per molecule of glucose (36 – 38 molecules) of ATP/GlucoseOccurs in 3 basic steps
12 GlycolysisUsing 2 ATP as activation energy, a glucose molecule is broken down into 2 Pyruvic Acid molecules. 4 ATP are produced, leaving 2 ATP netted. Occurs in cytoplasm.2. Krebs Cycle – in the Mitochondria, the 2 Pyruvic acids are broken down, releasing CO2 & producing 2 ATP3. Electron Transport Chain – Oxygen combines with hydrogen32 ATP are produced
14 How much more efficient is Aerobic Respiration than Anaerobic Respiration at releasing ATP from one molecule of glucose?Aerobic respiration yields 36 ATPAnaerobic respiration yields 2 ATP 2 ATP _______36: 2Bottom Line: Aerobic Respiration is 18x more efficient!!!
15 Muscle FatigueYou are a large organism and need a lot of ATP to keep you fueled.At times though, you may not be breathing correctly & therefore, are not taking in enough O2 to remain an aerobic organism.During this time, your body (muscle cells) converts to anaerobic respiration to give you some ATP. Hey, 2 ATP are better than none!Lactic acid accumulates in your muscle cells, acid burns the cells, causing you to cramp up & thus slowing down your activityWhen you begin to breathe normally again, the lactic acid breaks down and the “O2 debt” is paid