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Forms of energy important in human functioning

You have already learned 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.

Characteristics of chemical reactions

All chemical reactions begin with a reactant    , the general term for the one or more substances that enter into the reaction. Sodium and chloride ions, for example, are the reactants in the production of table salt. The one or more substances produced by a chemical reaction are called the product    .

In chemical reactions, the components of the reactants—the elements involved and the number of atoms of each—are all present in the product(s). Similarly, there is nothing present in the products that are not present in the reactants. This is because chemical reactions are governed by the law of conservation of mass, which states that matter cannot be created or destroyed in a chemical reaction.

Just as you can express mathematical calculations in equations such as 2 + 7 = 9, you can use chemical equations to show how reactants become products. As in math, chemical equations proceed from left to right, but instead of an equal sign, they employ an arrow or arrows indicating the direction in which the chemical reaction proceeds. For example, the chemical reaction in which one atom of nitrogen and three atoms of hydrogen produce ammonia would be written as N + 3H NH 3 MathType@MTEF@5@5@+=feaagyart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLnhiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=xfr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaaeOtaiaabccacaqGRaGaaeiiaiaabodacaqGibGaeyOKH4QaaeOtaiaabIeadaWgaaWcbaGaae4maaqabaaaaa@3EA4@ . Correspondingly, the breakdown of ammonia into its components would be written as NH 3 N + 3H.

Notice that, in the first example, a nitrogen (N) atom and three hydrogen (H) atoms bond to form a compound. This anabolic reaction requires energy, which is then stored within the compound’s bonds. Such reactions are referred to as synthesis reactions. A synthesis reaction    is a chemical reaction that results in the synthesis (joining) of components that were formerly separate ( [link] a ). Again, nitrogen and hydrogen are reactants in a synthesis reaction that yields ammonia as the product. The general equation for a synthesis reaction is A + B AB. MathType@MTEF@5@5@+=feaagyart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLnhiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=xfr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaqcaauaaiaabgeacaqGGaGaae4kaiaabccacaqGcbGaeyOKH4Qaaeyqaiaabkeaaaa@3D25@

Questions & Answers

what is pelvis
Aisha Reply
Complex of bones that connect the trunk and the legs,supports and balance the trunk.
What is d most heaviest organ in d body
Abraham Reply
The skin
What is the meaning? What does it entails to? What are the works of Arthropologists?
Orpha Reply
bones of appendicular skeleton
hemalatha Reply
Fore limbs, hind limbs, pectoral and pelvic girdle
Functions of the thoracic cage
Fereh Reply
protect all the organs and tissues from any impact or injury
It protects the heart other tissues in the chest region
why sickle cell carrier people don't get malaria
Boakye Reply
Bcos mosquitoes are not attracted by their blood due to poor oxygen
What is the amniotic fluid
bollywood Reply
structure of heart and it's function (10 mark )
Priyanka Reply
not possible
What is the best book on physiology?
cesar Reply
describe varicocele
what do you mean by peritoneum
Siba Reply
It is thick covering surrounding the abdomen
how to become good in Anatomy and physiology
What are is the last solution to abdomen pain in pregnant women
no it is in kidney
structure of heart and it's function
Serous membrane lining the cavity of the abdomen
it is four lobs structure and it is triangular in shaped. it 's function pumping the blood
explain root of lungs
Glomerular pressure -capsule pressure -colloid osmosis pressure
malulu Reply
how to describe mechanism of micturition
spleen is important?
helpful in destruction of rbc
It is imp in storing blood and destruction of microbes and harmful particles
ty sir
what are the sources of glucose in the body
describe mechanism of micturition
Pancreatic hormones with function
mami Reply
Insulin, which helps to regulate our blood sugar levels.
glucagon which is antagonistic to insulin increase the blood glucose level,. Somatostatin help to regulate the levels of both insulin and glucagon
thnks for helping
what is a lymph node.?
lymph nodes are small kidney shaped organs of the lymphatic system.
there are several hundred lymph nodes found mostly throughout the thorax and abdomen of the body with the highest concentrations in the auxiliary (armpit) and inguinal groin regions.
what is life
Yar Reply
life is the existence of an individual human being animal or plant
how I join this
to day I am new person and I can't participate questions so to morow I shall participate question sopleas excuse me
I had a debate earlier about nutrition and it didn't get a clear answer on that,can one tell me what the definition of nutrition.?
the nutrition is nourish person is feeling an nutrition
I think nutrition is the process of taking food and using it for growth, metabolism and repair.
life is full of happy and sorrow
life is achievement
life is the nothing but god gave us 1 body. and we all service k in this body. The things which we do for the Survivation for this body I felt that this is called as the life
Yes God gave us life but not god who gave us the life. Hope u understood what i meant by God n not god who gave life..... ?
What's the question?
Sherman Reply

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Source:  OpenStax, Anatomy & Physiology. OpenStax CNX. Feb 04, 2016 Download for free at http://legacy.cnx.org/content/col11496/1.8
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