What happens? Nothing happens unless you add a bit of energy—from a spark, perhaps. Clearly this reaction releases energy, but where did the energy come from? When you break the bonds, you get energy. As Derek Muller from Veritasium notes, this idea of energy stored in the chemical bonds is very wrong. To get a better understanding of energy in chemical bonds, let's consider a simplified model. When one hydrogen atom interacts with another hydrogen to form molecular hydrogen H 2 , many things are going on.
Still, one of the fundamental interactions is due to the electrostatic force between protons and electrons. Yes, there are quantum mechanical effects too—but let me stick with a simple model. In this model, I have two hydrogen atoms that experience some type of electric force attracting them. When they get really close, there is another force repelling the two atoms.
Chemical energy Chemical energy is energy stored in the bonds of chemical compounds , like atoms and molecules. Burning Questions. What is chemical energy? When a chemical reaction takes place, the stored chemical energy is released.
How is chemical energy used? Here are some examples of chemical energy in action:. Chemical energy in food The food we eat contains stored chemical energy. Chemical energy in wood Dry wood contains stored chemical energy. What are some other examples of stored chemical energy? Stored chemical energy can be found in:. Chemical batteries. Vehicle air bags. During aerobic respiration, oxygen reacts with the basic constituents of food, like carbohydrates, fats, and proteins. These are consumed as reactants to create ATP molecules.
For example, ATP is produced when glucose reacts with oxygen during aerobic cellular respiration. An energy transfer then occurs, which is used to break the molecular bond of ADP in order to add a third phosphate group, forming ATP molecules. The simplified chemical reaction is as follows:. Anaerobic respiration, on the other hand, is the main metabolic path in many species of bacteria and archaebacteria.
Since bacteria do not have specialised organelles , anaerobic respiration occurs in the cytoplasm. Instead of oxygen, anaerobic respiration uses sulfate, nitrate, sulfur, or fumarate as electron acceptors. The chemical energy stored in food is released by cells through the process of respiration. This process has four steps , and mainly produces ATP as the energy-carrying molecule that can be used by cells in their metabolic activities.
The four steps of the process are:. The total ATP yield of respiration is 30 or 32 per glucose molecule. Although the theoretical yield is 38 ATP molecules per glucose molecule, some are lost because of being spent in moving pyruvate from glycolysis, phosphate and ADP into the mitochondria. Chemical energy is stored in food because of the various molecular bonds in food and the electrochemical gradients that they create.
Depending on the type of food, these bonds may either be easy or difficult to break. The constituents of food, such as carbohydrates, fibres, minerals, fats, and proteins, act as reactants. They are broken down into basic molecules, like amino acids and glucose, which are either used as energy or reassembled and stored in other forms, like glycogen. Energy, potential energy, is stored in the covalent bonds holding atoms together in the form of molecules.
This is often called chemical energy. Except at absolute zero the coldest temperature it is possible to reach , all molecules move.
This movement is a form of kinetic energy, and the more the molecules move the more kinetic energy they have. Molecules in solids don't move much, they just vibrate. Molecules in liquids move faster and further, but they stick together enough to hold them in a small volume - the liquid. In a gas, however, the molecules are moving fast over 1, miles per hour , moving in all directions, and don't stay together so they spread out and fill the available volume.
When two molecules bump into one another two things can happen.
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