�ݺ�ߣ

INTRODUCTION
to
BIOCHEMISTRY
Prepared by
Dr. Chandrajiit Singh
Food Scientist
Krishi Vigyan Kendra –Rewa (MP)
E-mail: chandar30@gmail.com

Introduction to Biochemistry
• Bio + Chemistry
• Bio means life
• Chemistry is about chemicals, their reactions, interactions,
principles, process and methods sustaining life.

Definition of Biochemistry
Therefore we can say :
“It is a branch of science which deals with study of bio-molecules
and their role in living system”
or
“Chemistry of Life or Living Being is Biochemistry”
or
Biochemistry is a branch of science that seeks to describe the
structure, organization and functions of living matter in
molecular terms.

Living Things Can…
1. They are complicated and highly organized.
2. Each part of a living organism appears to have a specific
purpose of function
3. They are able to extract energy from the environment
4. They are capable of reproducing themselves through
generations
5. They exhibit common properties of living matter

History of Biochemistry
• Karl Scheele – Swedish founder of biochemistry. He studied
the chemical composition of matter in mid 1700.
• Schleiden & Schwann – formulated the cell theory in 1840.
• Walter Flemming – discovered chromosomes in 1875
• Carl Newberg – a German scientist who coined the word
biochemistry

• Hans Kreb – Proposed the Kreb cycle of the TCA in 1937.
• Embden & Mayerhoff – described the glycolytic pathway in
1925.
• James Watson & Francis Crick – described the double helical
structure of DNA in 1953

• Edward & Hans Buchner – found that extracts from yeasts
could bring about fermentation of sugar into ethanol in 1897
• Paul Boyer and J. Walker – discovered the “rotary engine”
that generated ATP in 1997.
• Danish J. Skou- studied the “pump” that drives sodium and
potassium across membranes

• Stanley Prusiner – discovered the organism that caused “mad
cow disease.”
• Ruska, et.al. – discovered the electron microscope and
provided a whole new level of insight into cellular structure.

Important Dates in Biochemistry

THREE PRINCIPLE AREA OF BIOCHEMISTRY
It is divided into 3 principal areas:
1. Structural chemistry
2. Metabolism
3. Chemistry of molecular genetics

Bio-Molecules
A bio-molecule or biological molecule is
any molecule that is present in living organisms, including
Large Macromolecules
Such as proteins, carbohydrate, lipids, and nucleic acids,
Small Molecules
such as primary metabolites, secondary metabolites, and natural
products.

Metabolites (Small Molecules)
Metabolites are small molecules which are the intermediates
and products of metabolism
Function of Metabolites:
Stimulatory and inhibitory effects on enzymes, catalytic activity
of their own (usually as a cofactor to an enzyme), defense, and
interactions with other organisms (e.g. pigments, ordants,
and pheromones)

Types of Metabolites
1. Primary Metabolites is directly involved in normal "growth",
development, and reproduction. Eg. Ethylene produced in
large-scale by Industrial Microbiology.
2. Secondary Metabolites: A secondary metabolite is not
directly involved in those processes, but usually has an
important ecological function and plant defense against
herbivory. Eg. include antibiotics and pigments such as resins
and terpenes etc.

Importance of Macromolecules:
1. Essential structures for the basis of life
2. Control and regulate these processes
3. Responsible for energy exchanges, irritability, metabolism,
mobility and reproduction

Importance of Biochemistry In Agriculture
1. In agriculture biochemistry plays a valuable role in farming,
fishery, poultry, sericulture, beekeeping etc.
2. Crop improvement with specific character.
3. Improve in productivity of specific crop.
4. Study the interaction of different pesticide molecules on pests,
their behaviour and control.
5. Toxicological effect of pesticide on human and animals for
safety purpose.

Importance of Biochemistry In Agriculture
6. Effect of use and method of use of nutrients and
micronutrients (Fertilizer and Bio- fertilizer) on productivity
and quality improvement of crop and consumer safety.
7. Effect and changes during storage of agriculture produce
and products, eg: ripening of fruits and spoilage.
8. Effect of preservatives and methods employed to enhance
shelf life of agricultural produce and products.
9. Effect of nutrients and nutrition on human being.

Chemical Composition of Living Matter
• Water – 70-90% (free and bound water)
• Solids – 10-30%
• Inorganic substances – 1% (Na, K, Ca, Mg, NH4, Cl-
, SO4,
PO4
-3
, CO3
-2
, etc.
• Traces of Fe, I2, Cu, Mn, Co, Zn are also present in
combination with organic radicals
• Rest- organic substances

Definition of Water
Water is a transparent , odorless, tasteless liquid, a compound is a
transparent, odorless, tasteless liquid, a compound of hydroge
n and oxygen, H2O, freezing at 32°F or 0°C and boiling at
212°F or 100°C, in a more or less impure state constitutes rain,
oceans, lakes, rivers, etc. It contains 11.188 % Hydrogen and
88.12 % Oxygen by weight.

Water
1. This is the major component of the cell and is often referred to
as an inert space filter in a living organism.
2. It is a strong dipole and has a high dielectric constant.
3. It is highly reactive with unusual properties different
physically and chemically from other common liquids.
4. Water and its ionization products H+
and OH-
are important
factors in determining the structure and biological properties of
proteins, nucleic acids, lipids, and other cell components.

Physical Properties of Water
Water has several other unique physical properties. These
properties are:
1. Water has a high specific heat. Specific heat is the amount of
energy required to change the temperature of a substance.
Because water has a high specific heat, it can absorb large
amounts of heat energy before it begins to get hot.

Physical Properties of Water (Continued ….)
2. Water in a pure state has a neutral pH. As a result, pure water
is neither acidic nor basic. Water changes its pH when
substances are dissolved in it.
3. Water conducts heat more easily than any liquid except
mercury.
4. Hydrogen bonds account for the surface tension, viscosity,
liquid state at room temperature, and solvent power of water.

Physical Properties of Water (Cont.)
4. Water molecules exist in liquid form over an important range
of temperature from 0 - 100° Celsius. This range allows water
molecules to exist as a liquid in most places on our planet.
5. Water is a universal solvent.
6. Water has a high surface tension.

Chemical Properties of Water
1. Water’s chemical formula is H2O.
2. The water molecule odd shape with both hydrogen atoms
occurring on the same side of the oxygen atom gives water its
ability to “stick” to itself and to other surfaces.
3. The hydrogen atoms create a positive electrical charge while
the oxygen atom creates a negative charge. The attraction to
one another is what causes water to form droplets.

Properties of Water of Biological Importance
1. Adhesion: water tends to stick unlike substances . Example is
water sticking to blood vessels.
2. Cohesion: which water molecules clings together due to
Hydrogen bonding; the surface film (top layer of water) is held
by surface tension. Example is spilled water forming a puddle.
3. Solvency: water is considered a universal solvent for its ability
to dissolve a wide range of substance since it is a polar

Properties of Water of Biological Importance (Cont.)
1. It is a universal solvent
2. It is an ideal biologic agent or medium for the ionization of
substances and therefore hastens chemical reactions.
3. It has a high specific heat, that is, it takes up more heat to
raise its temperature through 1o
C, thus allowing the body to
store heat effectively without greatly raising its temperature.
4. It possesses a high latent heat of evaporation
5. It has the capacity to conduct heat readily

Properties of Water of Biological Importance (Cont.)
1. It has a high specific heat, that is, it takes up more heat to raise
its temperature through 1o
C, thus allowing the body to store
heat effectively without greatly raising its temperature.
2. It possesses a high latent heat of evaporation
3. It has the capacity to conduct heat readily.

Hydrogen Ion Concentration (pH)
• pH is the negative log of the hydrogen ion concentration.
• pH = -log(H+
)
• Low H values correspond to high concentration of H+
and high
pH values correspond to low concentrations of H+
.
• Acids are proton donors and bases are proton acceptors
• Strong acids completely dissociate into anions and cations
even in strongly acidic solutions.

Hydrogen Ion Concentration (pH)
1. Strong bases are completely dissociated at high pH.
2. Many biochemicals are weak acids.
3. HCl and H2SO4are strong acids
4. KOH and NaOH are strong bases
5. Ca(OH)2is a weak base

Buffer Solution
1. A buffer solution is an aqueous solution consisting of
a mixture of a weak acid and its conjugate base, or vice versa.
2. Its pH changes very little when a small or moderate amount
of strong acid or base is added to it and thus it is used to
prevent changes in the pH of a solution.
3. Buffer solutions are used as a means of keeping pH at a nearly
constant value in a wide variety of chemical applications.

Buffer Solution (Cont.)
1. Many life forms thrive only in a relatively small pH range so
they utilize a buffer solution to maintain a constant pH.
2. In nature, the bicarbonate buffering system is used to regulate
the pH of blood.

Preparation of Buffer Solution
1. A buffer is made by mixing a large volume of a weak acid or
weak base together with its conjugate.
2. A weak acid and its conjugate base can remain in solution
without neutralizing each other.
3. The same is true for a weak base and its conjugate acid.

Importance of Biochemistry Final

How Buffer Works
1.HA (Weak Acid ) + A–
(Conjugate Base) A-
+ HA
2.Only place change takes place and do not go undergo any
reaction.
3.Weak Acid and Conjugate Base do not react as water but
remains in water as such.

How Buffer Works
4. However, weak acid and weak acid remains in high
concentration in water.
5. They react with strong acid or base if added without changing
the pH.

Strong Base is Added to a Buffer, Acid will Give Its
H+
:

Strong Acid is Added to a Buffer, Weak Base will
React with the H+
from the Strong Acid:

�ݺ�ߣ

Importance of Biochemistry Final

More Related Content

Importance of Biochemistry Final