Transcript Document
Animal Metabolism Tutorial Energetics and Cellular Respiration Metabolism On the whole, metabolism refers to the managing of material and energy resources within a cell. A metabolic road map depicting the sum total of the metabolic chemical reactions in cells ! Dots are molecules and lines are chemical reactions. Some types of energy… Kinetic Energy Potential (stored) Energy Heat (thermal energy) or the energy of molecular motion Chemical Energy stored in the bonds or molecules Electrical - movement of charged particles. Membrane potential a voltage gradient across a membrane (like a battery!) Light electromagnetic radiation Energy can be converted from one form to another… In this diagram of a hydroelectric dam, energy is being converted from the kinetic energy (movement) of water molecules into electrical energy, light, and a little heat too! …but it can never be created or destroyed! Life is all about energy and material conversions! Living organisms are always taking in energy and matter in one form and converting it into another form! Cellular respiration harvests the chemical energy stored in organic molecules to generate ATP! C6H12O6 + 6O2 Organic molecules (food) are like the $100 bills of energy currency – they store a lot of potential energy! ATP is like the “pocket change” of energy currency! CO2 + H2O Store small/useful amounts of energy which can be used to provide energy to do work in cell. Many processes that must occur in living organisms require energy! List a few additional processes that occur in living organisms which require the energy. • generating nerve impulses in the nervous system • contraction of muscle fibers • • • ATP = Cellular Energy! ATP (adenosine triphosphate) is a molecule that stores small (useable) amounts of energy which can be harnessed to do work in cells. ATP resembles which kind of organic molecule? How does ATP provide the energy to do work? This reaction releases 7.3 kcal of energy per mole of ATP This breakdown (also called hydrolysis) of ATP releases the energy needed to “drive” reactions in the cell that require energy. Do you remember from your last chemistry class what a mole is? Using ATP… + P Releases 7.3 kcal/mole of ATP Regenerating ATP… + P Requires 7.3 kcal/mole of ADP Where does the energy come from to regenerate ATP in our cells? + Requires 7.3 kcal of energy per mole of ADP P Releases 686 kcal of energy per mole of glucose! Enough energy to regenerate lots of ATPs! Cellular Respiration! C6H12O6 (Glucose) + O2 CO2 + H2O How do animals acquire these two reactants? What do animals do with this product? In what parts of the cell do the chemical reactions of cellular respiration occur? The Krebs Cycle and the Electron Transport Chains, the other 2 stages of cell respiration, occur in here! Glycolysis – occurs in the cell cytosol and regenerates a little bit of ATP. Most of the ATP in a cell is regenerated in the… Mitochondria! Mitochondria use oxygen (which animals breath in), and the chemical bi-products of the food we eat (like glucose – a simple sugar), to continually regenerate ATP. This ATP is then used to do the work of life. In the coming week’s lab… You will learn more about the different stages of cellular respiration in class, but in lab you will explore the effect that temperature has on the metabolic rate of an animal! Think about how outside (ambient) temperature changes might affect your metabolic rate. Remember that humans like other mammals are endotherms. How might it affect metabolic rate of animals like snakes, insects, or frogs which are ectotherms?