Would you rather…? —  Your parents are giving you $100 for your birthday. Would you rather receive the money as a $100 check or as $100 in cash? Why? —  What are the advantages and disadvantages for each option? All Living Things Require Energy Where do living things get energy? —  Heterotrophs…? —  Autotrophs…? —  Does food give you energy? The Answer? —  Yes and No —  Yes-­‐The food we eat has potential energy stored in the form of carbon-­‐based macromolecules (carbohydrates, lipids, and proteins) that we need to survive. —  No-­‐The energy stored within food is not in a type of energy that our cells can use. —  So, what is the energy cells use? ATP (Adenosine Triphosphate) —  All living things use ATP for energy. —  ATP helps cells build molecules and move materials into and out of the cell. —  ATP is like —  Cells can “spend” ATP, but they constantly have to work to make more ATP so they don’t run out. What is ATP made of? —  Adenine (nitrogenous base) —  Ribose (sugar) —  3 Phosphate Groups How do cells use ATP? Energy is released when the bond between the last two phosphate groups is broken. ADP (Adenosine Diphosphate) —  Created when the 3rd phosphate group is removed from ATP. —  This is the “uncharged” form of ATP. —  To “recharge” it, the 3rd phosphate group must be reattached. (This happens during Cellular Respiration.) How do cells get ATP? —  Remember, food does not contain ATP. —  Food contains macromolecules that can be broken down to make ATP. —  Plants and animals perform Cellular Respiration to convert the energy stored in food into ATP. —  The amount of ATP that can be made depends on the type of molecule that is used to create ATP. —  Glucose (carbohydrate/sugar) yields about 36 ATP molecules. —  A triglyceride (lipid/fat) can yield up to 146 molecules of ATP. Before you go… Food Contains Like Proteins Whose energy is converted into By cells.