SCI-ART LAB

Science, Art, Litt, Science based Art & Science Communication

Krishna: There are six primary forms of energy: chemical, electrical, radiant, mechanical, thermal, and nuclear. While there are other forms of energy (electrochemical, sound, and electromagnetic), these are usually a combination of the primary six forms. What’s more, these six forms of energy can be combined to create energy relying on one form or another.

Human bodies or any living bodies are made of matter.

About 99% of the mass of the human body is made up of six elements: oxygen, carbon, hydrogen, nitrogen, calcium, and phosphorus. Only about 0.85% is composed of another five elements: potassium, sulfur, sodium, chlorine, and magnesium (1).

The energy you are asking about is chemical and electrical energy in human bodies.

Our cells are specialized to conduct electrical currents. Electricity is required for the nervous system to send signals throughout the body and to the brain, making it possible for us to move, think and feel. The elements in our bodies, like sodium, potassium, calcium, and magnesium, have a specific electrical charge. Almost all of our cells can use these charged elements, called ions, to generate electricity.

Cell membrane is made up of lipids that create a barrier that only certain substances can cross to reach the cell interior. Not only does the cell membrane function as a barrier to molecules, it also acts as a way for the cell to generate electrical currents. Resting cells are negatively charged on the inside, while the outside environment is more positively charged. This is due to a slight imbalance between positive and negative ions inside and outside the cell. Cells can achieve this charge separation by allowing charged ions to flow in and out through the membrane. The flow of charges across the cell membrane is what generates electrical currents (2).

Cells control the flow of specific charged elements across the membrane with proteins that sit on the cell surface and create an opening for certain ions to pass through. These proteins are called ion channels. When a cell is stimulated, it allows positive charges to enter the cell through open ion channels. The inside of the cell then becomes more positively charged, which triggers further electrical currents that can turn into electrical pulses, called action potentials. Our bodies use certain patterns of action potentials to initiate the correct movements, thoughts and behaviours.

A disruption in electrical currents can lead to illness. For example, in order for the heart to pump, cells must generate electrical currents that allow the heart muscle to contract at the right time. Doctors can even observe these electrical pulses in the heart using a machine, called an electrocardiogram or ECG. Irregular electrical currents can prevent heart muscles from contracting correctly, leading to a heart attack (2).

Chemistry and chemical energy are all around us; they’re even part of us (we call it bio-chemistry and bio-chemical energy when involved with living beings). Chemical energy is a part of everyday life. It deals with chemical change when chemical compounds act and react at the molecular level. Chemical energy, is released when chemical potential energy undergoes a chemical reaction.

Chemical energy is contained within the bonds of chemical compounds at a molecular level. When there’s a chemical reaction between the molecules of chemical compounds, a new substance may form, and energy may be released. When chemical energy is released, it can be made to perform work.

In the human body, potential energy is stored in the bonds between atoms and molecules. Chemical energy is the form of potential energy in which energy is stored in chemical bonds. When those bonds are formed, chemical energy is invested, and when they break, chemical energy is released. Notice that chemical energy, like all energy, is neither created nor destroyed; rather, it is converted from one form to another. When you eat an energy bar before heading out the door for a hike, the honey, nuts, and other foods the bar contains are broken down and rearranged by your body into molecules that your muscle cells convert to kinetic energy (3).

Chemical reactions that release more energy than they absorb are characterized as exergonic. The catabolism of the foods in your energy bar is an example. Some of the chemical energy stored in the bar is absorbed into molecules your body uses for fuel, but some of it is released—for example, as heat. In contrast, chemical reactions that absorb more energy than they release are endergonic. These reactions require energy input, and the resulting molecule stores not only the chemical energy in the original components, but also the energy that fueled the reaction. Because energy is neither created nor destroyed, where does the energy needed for endergonic reactions come from? In many cases, it comes from exergonic reactions (3).

Forms of Energy Important in Human Functioning (3)

We know that chemical energy is absorbed, stored, and released by chemical bonds. In addition to chemical energy, mechanical, radiant, and electrical energy are important in human functioning.

  • Mechanical energy, which is stored in physical systems such as machines, engines, or the human body, directly powers the movement of matter. When you lift a brick into place on a wall, your muscles provide the mechanical energy that moves the brick.
  • Radiant energy is energy emitted and transmitted as waves rather than matter. These waves vary in length from long radio waves and microwaves to short gamma waves emitted from decaying atomic nuclei. The full spectrum of radiant energy is referred to as the electromagnetic spectrum. The body uses the ultraviolet energy of sunlight to convert a compound in skin cells to vitamin D, which is essential to human functioning. The human eye evolved to see the wavelengths that comprise the colors of the rainbow, from red to violet, so that range in the spectrum is called “visible light.”
  • Electrical energy, supplied by electrolytes in cells and body fluids, contributes to the voltage changes that help transmit impulses in nerve and muscle cells.

Okay we can go on and on like this —- that is a scientist’s specialization - a vast area of knowledge - but as a layman - you can ask me to stop here and answer your specific question.

After cardiac arrest, blood flow to the brain stops. Neurons and astrocytes detect that the oxygens levels drop, even before their own metabolism is affected. The neurons then switch off their function to get into an energy-saving mode: electrical activity stops, the neurons no longer send any signals. This is the flatline. Electrical energy ceases. Electrical energy is nothing special. Just like the chemical energy in our bodies, it breaks down into heat.

Flatline - ECG

Eventually, there is no longer enough energy to keep the ion pump going. The ion gradients collapse: Ions from inside the neurons stream out, and those from the outside stream in. As cells, and neurons in particular, have a carefully balanced chemistry, this change in the concentrations has dramatic consequences (4).

A massive depolarization occurs as the ion gradients collapse completely, releasing a great amount of energy.

Like every kind of energy, whether electrical, kinetic, sonic, or sports fever, the electrical potential in the body eventually becomes heat energy (it’s an entropy thing).

Where does all this energy go after cremation or burial of a living body? It will live on! The matter in your body also lives on!

Both matter and energy of a dead body are recycled. The chemical potential energy stored in the dead body eventually will be decomposed by bacterial activity, thus recycling energy into the environment as heat and other chemical potential forms of energy.

Traditionally, when humans have died, they have been buried in the ground. The process here is very similar to when animals and plants die. When they do die, they provide a nutrient rich organism for which much smaller organisms feed off of, these organisms can range from microorganisms like bacteria and fungi to insects like beetles or woodlice to large creatures like vultures, all of which help in the decomposition of an organism.

When these decomposers eat the dead organism, they unlock the energy stored in it and digest it, this is the same which goes for when we eat chicken or potato, it is dead, and we are getting the nutrients and energy stored up in it. This energy can be stored in fats or sugars in the food, and we have the same.

These organisms will then use the nutrients they need from what they have consumed, and effectively- poo- out what they don't. It is these nutrients which are either eaten by microorganisms or are taken in by plants.

After the death of a living organism, the energy it contains simply disperses into the surrounding environment. As the bodies cool, the excess heat energy we possess in life is distributed to the surrounding environment. The energy contained in the compounds in our bodies (sugar, fat, protein, almost everything) disperses as well. The bacteria and other organisms that decompose us absorb some of it, and much of it is lost too as heat to our surroundings as the chemicals break apart (either when eaten by decomposers or naturally) .

If we are not buried however, we may be cremated, this is like when we burn trees, coal, oil and natural gas as fuel. When we do combustion, we are releasing the stored up energy in it, and are breaking the bonds between the molecules.

These are the two typical ways we treat the body after we die, and how we lose energy just like everything else.

Now don’t ask me about soul or whatever you think as “energy”. Because there is no evidence of soul. And science doesn’t recognise it at all. Read here why:

Soul?! What is it according to science and scientists?

Footnotes:

  1. Composition of the human body - Wikipedia
  2. https://www.graduate.umaryland.edu/gsa/gazette/February-2016/How-th...
  3. Anatomy & Physiology
  4. The End Comes as a Wave

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