Chapter 9: Respiration aka: Getting energy from the cake

Think of Photosynthesis like baking a cake. The plant takes the raw materials (CO 2 & H 2 O), 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

Respiration Photosynthesis Relating Respiration to Photosynthesis Photosynthesis energy (Light), Photosynthesis takes in energy (Light), CO 2 & H 2 O and produces O 2 and Glucose. Respiration energy (ATP) Respiration takes in O 2 & Glucose and produces CO 2 & H 2 O with the release of energy (ATP)

How do we get the energy out of the food that we have consumed?

What is a calorie? It is a measure of the amount of energy in a nutrient. The amount of energy needed to raise the temperature of 1 gram of water, 1`c 1 Calorie = 1000 calories (a kilocalorie is how we measure calories) Carbohydrates = 4000 calories (4C)/gram Protein = 4000 calories/gram Lipid = 9000 calories/gram

Cellular Respiration Is the process by which organisms obtain the energy that they need by releasing the chemical energy stored in nutrients Nutrient = Glucose Chemical Energy = ATP

Two Types of Respiration Aerobic Respiration Aerobic Respiration – needs oxygen to release the energy in food C 6 H 12 O 6 + 6O 2 6CO H 2 O + 36 ATP Anaerobic Respiration Anaerobic Respiration – can release the energy from food without the need of oxygen. (Some bacteria & yeast) C 6 H 12 O 6 2CO Ethanol + 2 ATP C 6 H 12 O 6 2Lactic acid + 2ATP

Aerobic Respiration occurs in three steps Glen Glen 1.Glycolysis GlenGlycolysisGlen Occurs in the cytoplasm of all cells Glucose (6 Carbons) is broken down into 2 Pyruvic (3 Carbons each) acid (Pyruvate) molecules + 2 ATP (activation energy) Produces 4 ATP, netting 2 ATP 2 ATP 

Aerobic Phase of Respiration Occurs in the Mitochondria on the cristae Yields more ATP per molecule of glucose (36 – 38 molecules) of ATP/Glucose Occurs in 3 basic steps

1.Glycolysis Using 2 ATP as activation energy, a glucose molecule is broken down into 2 Pyruvic Acid molecules. 4 ATP are produced, leaving 2 ATP netted + 2 NADH Occurs in cytoplasm (just like anaerobic respiration) Krebs Cycle 2.Krebs Cycle – in the Mitochondria, the 2 Pyruvic acids are broken down, releasing 6CO 2 & producing 2 ATP + 8 NADH & 2FADH 2 3.Electron Transport Chain 3.Electron Transport Chain – Oxygen (the final electron acceptor) combines with hydrogen to produce WATER 32 ATP are produced

Krebs Cycle Pyruvic Acid 2 Carbon Dioxides Carbon Dioxide

NADH FADH 2 32 ATP NADH and FADH 2 produced during the Krebs Cycle will donate electrons to the ETC to generate 32 ATP molecules. O 2 H 2 O The final electron acceptor (with protons) will be O 2 to produce H 2 O The Electron Transport Chain

Energy Tally from Aerobic Respiration Song Time

Anaerobic Respiration Also known as Fermentation Occurs in the cytoplasm of yeast & some bacterial cells Since the organism are very small & simple, do not need much ATP

Fermentation The 2 Pyruvic Acids will break down into: 1.Alcohol + CO 2 (if yeast & some bacteria) C 6 H 12 O 6 2CO Ethanol + 2 ATP 2. Lactic Acid (some bacteria) C 6 H 12 O 6 Lactic acid + 2ATP Both forms will not produce any more than 2 ATP molecules

How much more efficient is Aerobic Respiration than Anaerobic Respiration at releasing ATP from one molecule of glucose? Aerobic respiration yields  36 ATP Anaerobic respiration yields 2 ATP  2 ATP _______ 36: 2 Aerobic Respiration is 18x’s more efficient!!!

Uses for Fermentation Yeast & some bacteria Used in baking, wine making & brewing industry Bacteria Lactic 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

Muscle Fatigue/Lactic Acid Build-up You are a big organism & need a lot of ATP to keep you fueled. At times though, you may not be breathing correctly & therefore, aren’t taking in enough O 2 to remain an aerobic organism. During this time, your body (muscle cells) convert 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 stop your activity & breathe normally Glucose Glucose song