2Cellular RespirationDefinition: the creation of energy in the form of ATP from organic (usually glucose) molecules Simplified, cellular respiration is C6H12O6 (aq) + 6 O2 (g) → 6 CO2 (g) + 6 H2O (l) + 36 ATP (eukaryotic cells) ΔG = kJ per mole of C6H12O6
3Steps in Cellular Respiration Three steps make up the process of cellular respiration:Glycolysis, which occurs in the cytosolKreb’s Cycle (or citric acid cycle) in the mitochondriaOxidative Phosphorylation (electron transport chain), also in the mitochondria
4Glycolysis Animation What you need to know: Occurs in the Cytosol (cytoplasm)Breaks up glucose into pyruvateYields 2 ATP moleculesThis would be fermentation(anaerobic respiration)5. Forms NADH to move to next step
5Kreb’s (or citric acid) Cycle AnimationWhat you need to know:Occurs in the mitochondriaCoEnzyme A facilitatesbeginning of this cycle3. Releases CO2Yields 2 ATP MoleculesYields NADH and FADH25. Breaking and formation of bonds releases energy
6Oxidative Phosphorylation AnimationWhat you need to know:Occurs in the cristae of themitochondriaNADH carries the electronsto start the chain, NAD+ goesback to the citric acid cycleATP Synthase transports H+ toform ATP from ADPReleases H2OYields 34 ATP Molecules
7How to get Energy?????Anaerobic Respiration: when only glycolysis phase is completed and 2 ATP are released. This will happen when there is a lack of oxygen (process of making alcohol)Aerobic Respiration: complete respiration in the presence of oxygen, yielding 36 ATP (some of the energy is used in the cycle) in eukaryotic cells and 38 ATP in prokaryotic cells(Bonus: Why is that??????)
8Fermentation in YeastYeast, yes the stuff used in bread to make it rise, often undergoes fermentation reactions. How can you design an experiment to see if the amount of sugar will effect the rate of anaerobic respiration? Observe the materials in front of you and think about the products of cellular respiration to help you do this. You will need to create a graph that represents your data, but collect data as a class! You may use excel to create your graph in the formal write up this time.