The biology of nutrition can be explained by a single molecule that fuels many processes. This molecule is called Adenosine Triphosphate, or ATP for short. It is formed as glucose is broken down into carbon dioxide and water through cellular respiration. According to Barron's Biology, ATP is "the special high-energy molecule that stores energy for immediate use in the cell" (87). ATP is composed of adenosine (which is a nitrogen base), three unstable phosphate tails that are susceptible to reactions, and a sugar called ribose. The phosphate tails are reactive because they are all negatively charged and are high-energy and unstable as a result. ( In terms of physics, free energy is released when these phosphate groups move from a state of high energy into a state of low energy. Free energy is denoted by delta G and is common in exothermic reactions. But I digress.) ATP easily converts to ADP, which the form of the molecule after one phosphate tail is taken away. As ATP converts into ADP, energy is released. This energy is crucial to cellular reactions. ATP is known as the 'cell currency' because of the energy it provides. The mitochondrion, which houses the reaction, is commonly known as the 'powerhouse' of the cell.
Why does ATP have so much energy to release? First of all, as said above, it is a pretty stressed out molecule. Second, it's not just one molecule releasing this energy - millions and millions of ATP molecules use this collective instability to produce a great deal of energy and basically run the show in your body. Single muscle cells produce and regenerate more than 10,000,000 ATP every single second.
Why does ATP have so much energy to release? First of all, as said above, it is a pretty stressed out molecule. Second, it's not just one molecule releasing this energy - millions and millions of ATP molecules use this collective instability to produce a great deal of energy and basically run the show in your body. Single muscle cells produce and regenerate more than 10,000,000 ATP every single second.
Photosynthesis and the SunPhotosynthesis in the inverse of cellular respiration; it is the way in which energy is circulated from the sun to the primary producers - all the way to the food that we eat. In a nutshell, the primary producers or the plants trap the energy of the sun and use it to transform carbon dioxide and water by electrolysis to a sugar called glucose. Cellulose, or starch, are forms of glucose that plants use to build cell walls, and this is why most of our plant-based foods have starch in them. Photosynthesis harnesses the energy of the sun and transfers it to the herbivores. Then, it travels up the food chain as energy concentrated by the primary consumers moves upwards to the secondary and tertiary consumers (only 10% on every trophic level though!)
As can be described to you by numerous biology textbooks, photosynthesis may occur through light reactions or dark (light-independent) reactions. Light reactions occur across thylakoid membranes and result in ATP and NADPH. Dark reactions occur in the stroma of chloroplasts and produce sugar by means of the Calvin cycle, which uses carbon dioxide to release glucose. |
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Cellular Respiration: How Your Cells Generate and Harness Energy
What Happens Next?
EXPERIENCE THE RUSH: Here is a cool, but not so healthy way to illustrate the biology of energy: take a simple carbohydrate, like a spoonful of sugar, and observe your energy level. Since glucose from the sugar directly enters your bloodstream, you feel energized for a brief time. Then, you slowly lose the feeling. Complex carbohydrates like bread are polysaccharides (which means that they are complex carbohydrates) and would not give you that sugar rush; only a simple carbohydrate like sugar would.
When ATP goes through the process of hydrolysis, its energy is said to be "coupled" because it transfers its lost phosphate group to another molecule. This molecule now has an additional molecule (it is a 'phosphorylated' molecule) and thus undergoes a change of some sort to perform work- a change in action or a change in CONFORMATION that results in an action.
This happens over and over - the body can regenerate ATP just by adding another phosphate group to ADP, which is how it constantly provides energy.
The energy is used for the activities that promote your life, such as breathing and digesting; circulating and immunizing. The culmination of all these processes is called your metabolism. According to MedicinePlus Encylopaedia, the lengthy definition of a metabolism is as follows:
"Metabolism refers to all the physical and chemical processes in the body that convert or use energy, such as: breathing, circulating blood, controlling body temperature, contracting muscle, digesting food and nutrients, eliminating waste through urine and feces, and the functioning of the brain and nerves."
When your metabolism is fast, you use a lot of the energy that you produce in the body. This means that you burn off calories faster. (Yes, that's what your grand-aunt means when she bemoans your weight.) If you have a slower metabolism, your body tends to take longer to 'spend' the energy that it produces and stores it. This is what comprises the adipose tissue in your body - fat.
When ATP goes through the process of hydrolysis, its energy is said to be "coupled" because it transfers its lost phosphate group to another molecule. This molecule now has an additional molecule (it is a 'phosphorylated' molecule) and thus undergoes a change of some sort to perform work- a change in action or a change in CONFORMATION that results in an action.
This happens over and over - the body can regenerate ATP just by adding another phosphate group to ADP, which is how it constantly provides energy.
The energy is used for the activities that promote your life, such as breathing and digesting; circulating and immunizing. The culmination of all these processes is called your metabolism. According to MedicinePlus Encylopaedia, the lengthy definition of a metabolism is as follows:
"Metabolism refers to all the physical and chemical processes in the body that convert or use energy, such as: breathing, circulating blood, controlling body temperature, contracting muscle, digesting food and nutrients, eliminating waste through urine and feces, and the functioning of the brain and nerves."
When your metabolism is fast, you use a lot of the energy that you produce in the body. This means that you burn off calories faster. (Yes, that's what your grand-aunt means when she bemoans your weight.) If you have a slower metabolism, your body tends to take longer to 'spend' the energy that it produces and stores it. This is what comprises the adipose tissue in your body - fat.