![]() ![]() If free H atoms, which are +1, get added to the O atoms that aren’t bonded to two things, then the net charge is zero.) Each phosphate is a PO 4 (oxygen has a charge of -2 and there are 4 of them, for a total of -8, and P has a charge of +5, so the net charge on the phosphate group is -3. However, the battery doesn’t get thrown away when it’s run down–it just gets charged up again. The ATP molecule is just like a rechargeable battery. When the cell has extra energy (gained from breaking down food that has been consumed or, in the case of plants, made via photosynthesis), it stores that energy by reattaching a free phosphate molecule to ADP, turning it back into ATP. The energy holding that phosphate molecule is now released and available to do work for the cell. If a cell needs to spend energy to accomplish a task, the ATP molecule splits off one of its three phosphates, becoming ADP (Adenosine di-phosphate) + phosphate. Think of it as the “energy currency” of the cell. The cell has a special kind of molecule for storing that energy, and it’s called ATP.ĪTP (Adenosine tri-phosphate) is an important molecule found in all living things. Each of these food types requires a different breakdown process, and we’ll look at those later, but the goal is the same–take the energy that held those food molecules together and release it so that it can be stored in a form that the cell can use later to build what it needs. 2) Breaking down the food molecules releases the energy that was holding them together, and that released energy is temporarily stored by the cell for the re-building process. 1) Once the food atoms and groups of atoms (molecules) are broken down, they can be built back up into the specific kinds of things the organism needs, like bone, muscle, skin, hair, feathers, fur, bark, leaves, etc. Living things break down the three major categories of foods ( proteins, fats, and carbohydrates) into their constituent parts, the individual lego blocks, for two reasons. Here's a brief video lecture that summarizes this concept. Your body does exactly that when you eat your food. ![]() It took a lot of energy to organize those blocks into that complex structure, and breaking the blocks apart releases that energy and frees the blocks so that they can be built back up into new things. Imagine that the hamburger you’re having for dinner, made of proteins, fats, and carbohydrates, is a collection of lego blocks of various colors and shapes. Some of these reactions use stored energy to build things up, which we call anabolism, while other reactions break things down, releasing energy that can be stored for future use, and this is called catabolism. Your metabolism is the collection of chemical reactions that occur in your cells to sustain life. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |