Chemistry of Life
Life is an important thing that makes people live. The life of a living organism is made
possible by the availability of various chemical elements, atoms, and compounds. Living
organisms cannot exist without the chemical elements that they are made. Chemistry is,
therefore, part of life. Major elements such as sodium and potassium play key roles in the
chemical processes of life. Life applies chemistry to be able to understand the manner in which
living organisms can manage to reproduce, grow, move, think, eat, and do whatever they can.
Biologists apply chemistry to study the living organisms. The fundamental elements that
constitute essential minerals are the sulfur, oxygen, phosphorous, nitrogen, hydrogen and carbon.
Understanding the chemistry of biologically important molecules gives insight into the structure
and function of cells and other body processes. Biological macromolecules include proteins,
carbohydrates, lipids and nucleic acids define the properties of a cell. This essay analyses the
chemical context of life, water and life, and structure and function of the major biological
Chemical Context of Life
Chemistry and biology are highly related. Evidently, everything is made up of many atoms
including all living organisms. The matter is made up of chemical elements that are in both pure
and combined forms referred to as compounds (Jordan, Trace, and Kallenbach). Living
organisms are made up of matter since matter is anything that has mass and occupies space.
Therefore, living organisms are made up of atoms, elements molecules, and compounds. To
possibly understand the functioning of the living systems, it is plausible to understand the
chemical composition of those organisms (Thomas, Fryhle, and Snyder). An atom is made up of
protons, neutrons, and electrons which play an essential part in the body structure of a living
organism. Out of the three particles in an atom, electrons are the most crucial since they
determine the behavior of atoms and are involved in the production of energy in biological
systems, photosynthesis, and cellular respiration. An atom and hence living organisms gain the
potential to work from the electron which has the potential energy (Jordan, Trace, and
During the electronic transition, the electron moves from one energy level to another
hence releasing or absorbing energy (Jordan, Trace, and Kallenbach). When electron moves to a
higher energy level, it absorbs energy, while when it moves from to a lower energy level,
towards the nucleus, the electron losses energy. This losing and gaining energy is essential in the
process of photosynthesis. The distribution of electrons determines the chemical behavior of an
atom. The chemical behavior of an atom relies on the valence electrons. As a result, elements
with a full valence shell are chemically inert since they have a stable configuration (Jordan,
Trace, and Kallenbach). Additionally, the chemical reactions involve the transfer of electrons
from one atom to another. When this happens, either oxidation or reduction takes place. If
electrons are lost, the atom undergoes oxidation, and if the electrons are gained the atom that has
received, it undergoes reduction. These reduction and oxidation reactions are essential in the
body for the processes of cellular respiration and photosynthesis.
Various elements of life include hydrogen, carbon, nitrogen, and oxygen which make up
96% of living matter (Thomas, Fryhle, and Snyder). The other 4% consist of sulfur, potassium,
phosphorous and calcium (Thomas, Fryhle, and Snyder). These elements are all required in the
body although I different quantities. A human being requires 25 elements while a plant requires
17 elements. The property of an element is dependent on the structure of its atoms.
The chemical bonding between atoms dictates the formation and function of molecules.
In this regard, the atoms with incomplete valence shells can share or transfer valence electrons
with certain other atoms (Thomas, Fryhle, and Snyder). Additionally, the interactions usually
result in atoms staying close together and held by the chemical bonds. The chemical bonds are
hence the ones that augment the body. Those bonds include the covalent bonds, ionic bonds,
hydrogen bonds, and van der Waals interactions (Jordan, Trace, and Kallenbach). Temporal
interactions between molecules are highly involved in the various biological signals and
processes in the body. A good example is that weak bonds within large molecules like the
proteins help in the creation of three-dimensional shapes and resulting activity of those
molecules. The molecular shape relates to the molecule’s biological function. A molecule,
therefore, has a characteristic size and shape that affects the interactions with other molecules.
The chemical reactions involve either the breaking or making of chemical bonds to have matter
transformed into different forms (Thomas, Fryhle, and Snyder). Atoms and molecules are
responsible for various chemical reactions. Examples of chemical reactions include the
photosynthesis (Thomas, Fryhle, and Snyder).
Water and Life
According to Caso (2012), life cannot be sustained without water. Water plays a significant and
unique role in all living organisms. Various chemical properties of water make it indispensable
for living creatures. As a result, the chemistry of life is the chemical composition of water. Water
is formed when the two hydrogen atoms bond covalently with one atom of oxygen. Sharing or
electrons are unequal since oxygen pulls electrons a little closer to itself and a bit further from
the two hydrogen atoms.
According to Ghose (2015), water also plays a role in the removal of the waste products
from a body of a living organism. The liquid acts as a universal solvent hence able to dissolve
every substance and remove them from the body. Ball established that water molecule has a
polarity which makes hydrogen atoms tend to bunch on one side of the molecule and create a
positive region; on the other hand, oxygen end has a negative charge. The positive hydrogen end
thus attracts negative ions while the negative end attracts the positive ions. These make water a
universal solvent except for non-polar compounds. Due to this dissolving property, water is used
in the body to dissolve and transport many substances. The body of a human being consists of
about 70% water to aid in different body functions. It is also necessary for many biochemical
reactions. Water is highly used in various biochemical reactions such as photosynthesis and
cellular respiration. In photosynthesis, water is used as a reactant in the process while in cellular
respiration water is used as a product. These are evidence that many life processes are dependent
on water and life could not be possible without water.
Carbon and Molecular Diversity of Life
Carbon is a versatile element that can build an infinite amount of molecules. These are possible
since carbon has the capability of forming skeletons using its four valence electrons. According
to Jordan, Trace, and Kallenbach, carbon is the building block of molecules, and since living
organisms are made up of molecules, carbon is the element of life. The carbon molecule has six
electrons arranged in energy levels in which the first level has two electrons; the second has four
giving it the capability to gain or lose electrons and hence form both negatively and positively
charged ions. Filling valence shell requires that carbon forms the covalent bonds. The four
intersection points make carbon a versatile element. Due to its versatility, carbon can form bonds
with nitrogen, oxygen, and hydrogen (Kelly). These four elements are the basic elements of life.
Each combination has its particular purpose in life. An example is carbon and hydrogen which
are responsible got numerous organic compounds of life. The combination of carbon and
hydrogen forms a group of compounds known as hydrocarbons which play significant roles in
the body of a living organism. The hydrocarbons are responsible for fat in the body and
petroleum products. According to Kelly, when living organisms die, they are later found to
consist hydrocarbons that decompose to become petroleum fuels. These indicate that living
organisms are made up hydrocarbons.
The carbon skeletons are diversity, and they make the organic molecules diverse as well.
Carbon chains are the ones that form the skeletons of most organic molecules. The chains take
different forms in which they can straight, branched or arranged in rings. The various forms
could be complicated structures such as isomers, polymers or monomers among others. Isomers
are molecules that have the same formulas but have different structures and play various
According to Kelly, every compound has its functional group that distinguishes it from
another and which determine its functioning. They are, therefore, the components of the organic
molecules that are frequently used in chemical reactions. A good example is an estradiol and
testosterone which are both steroids having common carbon skeletons, however, due to the
difference in functional groups, one functions as a female sex hormone and the other as the male
sex hormone. The chemistry of life has six important functional groups and these include;
hydroxyl, carbonyl, carboxyl, amino, sulfhydryl, and phosphate (Kelly). For compounds that are
made of carbon and other elements, they are studied under organic chemistry. The organic
compounds can be simple molecules or colossal (Solomons, Fryhle, and Snyder). Mostly, the
organic compounds are made up of carbon atoms and hydrogen atoms. There is an idea known as
vitalism which argues out that organic compounds arise only in organisms. This idea was,
however, disapproved by chemists who synthesized these compounds in a laboratory. According
to the classic experiment that was performed by Stanley Miller, abiotic synthesis of organic
compounds is plausible. As established by Stanley in his experiment, the synthesis of organic
compounds adjacent to volcanoes is seen as a stage in the origin of life (Jordan, Trace, and
According to Jordan, Trace, and Kallenbach the chemical elements of life include the
living matter which mainly consists of nitrogen, hydrogen, oxygen, and carbon. These elements
are linked together using covalent bonds. The wide variety of various organic molecules with
their unique properties comes as a result of the critical pattern of the carbon skeleton and the
functional groups attached to its skeleton. Jordan, Trace, and Kallenbach established that these
unique arrangements are what living organisms are made of and they are made of carbohydrates,
proteins, and DNA among other molecules. These play significant functions in the body of a
living organism, and they distinguish that living matter is composed of carbon compounds.
Structure and Function of Large Biological Molecules
There are four classes of large biological molecules that make up the living things, and these
include nucleic acids, proteins, lipids, and carbohydrates. Interestingly, these large molecules are
made up of carbon atoms (Thomas, Fryhle, and Snyder). Large molecules are known as
macromolecules and are composed of thousands of covalently connected atoms. The function of
each small or large molecule is determined by the structure of that particular molecule.
Macromolecules are polymers that are built from the monomers (Jordan, Trace, and Kallenbach).
Monomers are small building block molecules that join together to form a long molecule known
as a polymer. There are various categories of polymers such as carbohydrates. Carbohydrates are
the sugars as well as their polymers. The simplest carbohydrates are known as simple sugars or
the monosaccharides. The macromolecular carbohydrates include the polysaccharides which are
made of many sugar building blocks (Thomas, Fryhle, and Snyder). The monosaccharides have
their CH2O as their molecular formulas. Their classification is based on the location of their
functional group, carbonyl group (ketose or aldose) and the number of the carbon atoms in the
carbon skeleton. Below is the basic structure of some of the monosaccharide.
These are the major fuel for cells and at as raw material for building molecules. When
two monosaccharides undergo dehydration reaction, a disaccharide is formed (Jordan, Trace, and
Kallenbach). They are joined together through a covalent bond known as glycosidic linkage.
Polysaccharides are made of many monosaccharides and are therefore polymers of sugars. It is
the sugar monomers and the position of glycosidic linkages that determine the function of the
polysaccharide. The starch is a polysaccharide that is used for storage and made up of glucose
monomers (Thomas, Fryhle, and Snyder). Plants store their surplus starch as granules within
chloroplasts and other plastids. Glycogen is a polysaccharide that stores surplus in animals.
Proteins have polypeptides that are twisted, coiled and folded into a unique shape. There
are, however, some proteins that have unfolded areas. It is the sequence of the amino acids that
determine the three-dimensional structure of the protein. Just like in other molecules, the
structure of a protein determines its function. A protein structure has four levels of which include
the primary, secondary, tertiary and quaternary structure (Jordan, Trace, and Kallenbach). A
primary structure has the unique sequence of amino acids; the secondary structure has coils and
folds in the peptides, the tertiary structure has interactions among various side chains while
quaternary structure arises when the protein has multiple polypeptide chains. Changing the
primary structure of a protein is dangerous since it affects its ability and function (Thomas,
Fryhle, and Snyder). A good example is a substitution of a single amino acid in the protein
hemoglobin resulting to sickle – cell disease.
According to Thomas, Fryhle, and Snyder, the nucleic acids are responsible for storing
transmitting and helping to express hereditary information. The nucleotides make up the DNA.
The function of nucleic acids is to provide restriction for its replication. It also directs the
synthesis of messenger RNA, and through mRNA, it controls the synthesis of proteins. The
synthesis of proteins talks places in the ribosomes.
The body of every living organism is made up of various chemicals. Atoms, molecules,
elements, and compounds make up the entire part of a living organism. These have been proved
without doubt through various experiments performed by the scientist. Chemistry is therefore
inalienable from biology which studies life. Each chemical group of elements plays a particular
role that is determined by its structure. In conclusion, the chemistry of life is a reality.
Anderson, Nancy. Water and Life. , 2017. Internet resource.
Ball, P. “Water and Life: Seeking the Solution.” Nature. 436.7054 (2005): 1084-5. Print.
Caso, Adolph. Water and Life. Place of publication not identified: Branden Pub Co, 2012. Print.
Ghose, Tia. “Why Is Water So Essential For Life?” Live Science, 2015,
Jordan, Trace, and Neville R. Kallenbach. Chemistry: The Molecules of Life. , 2017. Print.
Kelly, Andrew. Carbon. Fitzroy, Vic: Wild Dog, 2013. Print.
Solomons, Thomas W. G, Craig B. Fryhle, and Scott A. Snyder. Organic Chemistry. , 2017.