12th hacker series

Biomolecules
-

introduction
BIOMOLECLIES

Carbohydrate Hormones

glucose
-
Vitaming

Protein Nuclei and enzyng

futose
-

-
AnnoAciel
- diasauchands
-

starch

Carbohydrates
• the carbohydrates may be defined as optically, active, polyhydroxy
aldehyde or ketones or the compound which produce such units on
hydrolysis
• Some of the carbohydrates, which are sweet in taste are also called
sugars
eg-glucose (H18 >
-
polyhydrony alddyde
CH,2
Fructose >
-
polyhydrony before
 Fructose
yes
-sucrose glucose +

Classification of carbohydrates
Monosaccharides
• a carbohydrate that cannot be hydrolysed further to give simpler unit
of polyhydroxy aldehyde or ketone is called a monosaccharide.
• Some common examples are glucose, fructose, ribose, etc
Oligosaccharides
• carbohydrates hat yield 2 to 10 monosaccharide units on hydrolysis
are called oligosaccharides
• They are further classified as disaccharides, trisaccharides,
tetrasaccharide , etc. Depending upon the number of Monosaccharide ,
they provide on hydrolysis.
• Amongst these, the most common are disaccharides
• The two monosaccharide units obtained on hydrolysis of the
disaccharides may be same or different
• For example, one molecule of sucrose on hydrolysis gives one molecule
of glucose and one molecule of fructose, whereas maltose gives two
molecules of only glucose

Polysaccharides
• carbohydrates, which yield a large number of monosaccharide units
on hydrolysis are called polysaccharides
• some common examples are starch, cellulose, glycogen, gums, etc
• Polly saccharides are not sweet in taste, hence they are also called
non-sugars

The carbohydrates can also be classified as either reducing or non-

reducing
• all those carbohydrates, which reduce fehling’s solution, and tollen’s
reagent are referred to as reducing sugar
• All monosaccharides, whether Aldose or ketose are reducing sugar
 Classification of carbohydrates
Monosaccharides
• monosaccharides are further classified on the basis of number of
carbon atoms and the functional group present in them
• if a monosaccharide contains an aldehyde group, it is known as
aldose and if it contains a keto group, it is known as ketose

Glucose
• glucose occurs freely in nature as well as in the combined form
• it is present in sweet fruits and honey
• Ripe grapes also contains glucose in large amounts
• Mechanism of preparation of glucose:
• 1) from sucrose(cane sugar)
% 2H2201 CH206 + CH 20
or
1
H2801 puctose
sucrose in alcobidic
sol
glucose
• 2) from starch- commercially glucose is obtained by hydrolysis of
starch by boiling it with dilute H2SO4 at 393 Kelvin under pressure
"st005th Eagles m CH120

• glucose is an Aldohexose and is also known as dextrose

• it is the monomer of many of the larger carbohydrates, namely
starch, cellulose
• it is probably the most abundant organic compound on the earth
• it was assigned the structure given below on the basis of the following
evidences
• 1) its molecular formula was found to be C6H 1206
 • 2) on prolonged heating with HI, it forms n- hexane, suggesting
that all the six carbon atoms are linked in a straight chain

H -acc At a

• glucose reacts with hydroxylamine to form an oxime and adds a

molecule of hydrogen cyanide to give cyanohydrin . This reaction.
confirm the presence of carbonyl group in glucose.
c N On

"PHNOH-
cro H -
= =

'MOHI or
Go
zon
CH2OH
-
hysonylami Genon
Quie
• glucose gets oxidised to 6 carbon carboxylic acid( gluconic acid) on
reaction with a mild oxidising agent like bromine water
• This indicates that the carbonyl group is present as an aldehydic
group

T otr garconi
a s

hon
CN

- c-on

oon
n

or
I
+ new -
(CHOH)y
I

COU
dai
candy
• acetylation of glucose with acidic anhydride gives glucose
pantaacetate, which confirms the presence of 5 0H groups
• Since it exist as a stable compound. 5 OH groups should be attached to
different carbon atoms.

aroc - -t
a
you i =
0-c-al
• oxidation with nitric acid , glucose as well as gluconic acid, both
yield or dicarboxylic acid, saccharic acid.
• this indicates the presence of primary alcoholic group in glucose

Hiw
ntieands
cook
arou Isaahesie
CH0N
aid]
Egluse] and)
Egliconic
 Open chain structure
• molecular formula of glucose is experimentally found as CH, 20
CH0

icon)a
mon
• epimers: they are pair of diastereomers that differ only in the
configuration about a single carbon
• anomers: they are diasteromers that differ in the configuration at
the acetal or hemiacetal C atom of the Sugar in its cyclic form or
anomers are epimers, whose confirmation differ only about C1
and
• for example-
glucess
-DH
AD-t) & B-DIH) are anomers
,

B-D-1-)- fructose are anomers

Fructose
• It occurs both in combined as well as free state
• Fructose is named as fruit sugar because it is present in honey and
more sweet fruits in free state
• it is the sweetest monosaccharide and present in cane sugar and
insulin and combined state
• it is also known as alpha- Laevulose I.e, naturally occurring fructose is
laevorotatory
• Preparation
• 1) by acid hydrolysis of cane sugar
4242201 +
HCHROs +

• 2) by enzymatic action on sucrose

glecost fructore
124220 ,, invertase
,
 Sucrose
• these two monosaccharides are held together by a glycosidic linkage
between C1 of 4-D glucose and C2 of.B-d fructose
• Since the reducing group of glucose and fructose are involved in
glucosidic bond formation, sucrose is a non-reducing sugar
 Maltose
• another disaccharide maltose is composed of 2 D-glucose units in
which C1 of one glucose
• 1) is linked to C4 of another glucose unit
• 2) The free aldehyde group can be produced at C1 of the second glucose
in solution and it shows reducing property, so it is a reducing sugar

Lactose
• it is more commonly known as milk sugar since this disacchride is
found in milk
• it is composed of beta D glucose and beta D galactose
• The linkage is between C1 of galactose and C4 of glucose
• Free aldehyde group may be produced at C1 of glucose unit, hence it is
also reducing sugar
Polysaccharides
Starch
• it is the main storage polysaccharide of plants
• it is the most important dietary source for human beings
• High content of starch is found in cereals, roots, tubes, and some
vegetables
• it is a polymer of X-glucose and consist of two components, amylose
and amylopectin

• amylose is water is soluble component which constituents about 15 to

20% of starch
• Chemically, amylose is a long branch chain with 200 to 10004- glucose
units held together by C1 - C4 glycosidic linkage

Cellulose
• cellular occurs exclusively in plants, and it is the most abundant
organic substance in plant kingdom
• it is a predominant constituent of cell wall in plant cells
• it is a straight chain polysaccharide composed of only beta D glucose
units which are joined by glycosidic linkage between the C1 of one
glucose unit and C4 of the next glucose unit
 Glycogen
• the carbohydrates are stored in animal body as glycogen
• it is also known as animal starch because it structure is similar to
amylopectin and is rather more highly branched
• it is present in the liver, muscles and brain
• When the body needs, glucose enzymes, break the glycogen down to
glucose
• Glycogen is also found in yeast and fungi

Protein
• they occur in every part of the body and form the fundamental basis of
structure and function of life
• they are also required for growth and maintenance of the body
• The word protein is derived from the greek “ proteios “ which means
primary or of prime importance
• All proteins are polymers of amino acid
H
↑ >
- -coo
R
R-C-WOH
-

WH west

Classification of amino acid

• depending on the relative number of amino (- NH2) and carboxyl (-
COOH) functional group, amino acid are classified as acidic, basic
and neutral
• More number of amino group, make it basic and more carboxyl group
make it acidic , equal number of amino and carboxyl group, make it
neutral
Properties of amino acid
• except glycine, all other naturally occurring amino acids are optically
active since Alpha carbon is asymmetric
• L amine acids are represented by writing the. NH2Group on the left
-

hand side.
 • in actual sense acidic properties due to COOH group and basic
properties due to NH2 group because it exist as zwitter ion

Zwitter ions
• due to presence of an acidic and basic group in the same molecule, most
of the amino acids are neutral and exist largely as dipolar or zwitter
ions or inner salts in which proton from the carbon group has been
transferred to the amino group and thus a dipolar ion containing both a
positive and a negative charge is formed

Peptide linkage
• amino acid units are linked together by peptide linkage and form
polypeptides
• in a polypeptide structure, free amino group i.e, N terminal residue is
written on the left hand side and the free carboxyl group on the right
hand side of the chain

Essential and non-essential amino acid

• the amino acids which can be synthesised in the body are known as
non-essential amino acids
• on the other hand, those which cannot be synthesised in the body and
must be obtained through diet are known as essential amino acid

Classification of proteins
On the basis of molecular structure
• 1) fibrous protein- when polypeptide chain run parallel and are held
together by hydrogen and disulphide bonds, then fibre like structures
are formed. Such proteins are generally insoluble in water . example-
keratin, collagen, myosin, etc
 • 2) globular protein- the poly peptide chain in these proteins is folded
around itself to form spheroidal shape. The folding takes place in a
manner such that - hydrophobic parts are pushed inwards and
hydrophilic parts are pushed outward
• as a result, water molecules interact strongly with the polar groups and
hence globular proteins are soluble in water. As compare to the fibrous
proteins, these are very sensitive to small changes in temperature and
pH . example- insulin, albumin, antibodies, haemoglobin, fibrinogens,
etc

On the basis of chemical composition ( not in NCERT)

• 1) simple proteins: these proteins on hydrolysis give only amino acids.
example - albumin in the white portion of eggs, keratin in hair, nails,
horns, etc
• 2) conjugated proteins- these are the proteins in which the protein part is
combined with non-protein part. These proteins on hydrolysis give a
non-protein in addition to the amino acids. The main function of the
prosthetic group is to control the biological function of the protein.
Prosthetic groups are carbohydrate, phosphate group, lipids, and so on.
Caesin of milk, haemoglobin of blood are conjugated proteins
• 3) derived proteins: these are the degradation products obtained by
partial hydrolysis of simple or conjugated proteins with acids, alkali or
enzymes. Example- proteases, peptones, and polypeptide

Proteins
• primary structure of protein: proteins may have one or more polypeptide
chains
• Each polypeptide is a protein has amino acid linked with each other in a
specific sequence, and it is the sequence of amino acids that is said to be
the primary structure of that proteins. Any change in this primary
structure I.e, the sequence of Amino acid It creates a different protein.
• the secondary structure of protein: refers to the shape in which long
polypeptide chain can exist
• They are found to exist in two different types of structures- alpha
helix, and beta plated sheets structures
• These structures arises due to regular folding of the backbone of the
polypeptide chain due to hydrogen bonding between the NH group
of the peptide bond
• Helix is one of the most common ways in which a poly
• peptide chain forms all possible hydrogen bonds by twisting into a
right hand screw (helix) with the NH group of amino acid residue
hydrogen bond to the CO of an adjacent turn of the helix

• tertiary structure of proteins: the tertiary structure of proteins

represents overall folding of the polypeptide chain I.e, further folding
of the secondary structure
• it gives rise to 2 major molecular shapes viz fibrous, and globular
• The main forces which stabilise the 2° and 3°, structure of proteins are
hydrogen, bond, disulphide, linkages, Vanderwaals , and electrostatic
forces of attraction
• quarterary structure of proteins: some of the proteins are composed of
two or more polypeptide chain referred to as subunits
• The special arrangement of these sub units with respect to each other
is known as quaternary structure

Denaturation of proteins
• a protein found in a biological system. Having a unique three
dimensional structure and a specific biological activity is called a
native protein.
• When a protein in its native form is subjected to a physical change like
change, temperature or pH, the hydrogen bonds are disturbed
• as a result, globules unfold and Helix get uncoiled and protein lose is
biological activity
• This is called denaturation of proteins
• During denaturation, secondary and tertiary structures are destroyed,
but primary structures remain intact
• Eg- coagulation of egg white, curdling of milk
Enzymes
• enzymes are very specific for a particular reaction and for a particular
substrate
• They are generally named after the compound or class of compounds
upon which they work
• For example- the enzyme that catalyse hydrolysis of maltose into
glucose is named as Maltase

Composition of enzymes (not in NCERT)

• chemically, all enzymes are globular proteins
• However, some enzymes are also associated with some non-protein
component called the co-factor for their activity
• These co-factors are of two types
• 1) inorganic ions In't Mgzt Must
-

, ,

• 2) organic molecules- these are also of two types

• I) coenzymes: these are small organic molecules which are loosely held
to the protein and can be easily separated by dialysis.
• II) prosthetic group: these are also organic molecules which are tightly
held to protein by covalent bonds, but can be separated by only careful
hydrolysis. Most of these are derived from vitamins such as biotin.
Enzymes are vital for biological process without the life process would
be very slow.

Hormones
• these chemicals, which are secreted by ductless glands and transported
to different parts of the body by the blood stream, where they control
different physiological actions of the body
• The word hormone is derived from greek language, which means to
gear up or to excite
• Hormone control cell and tissue growth, heartbeat, blood pressure,
secretion of digestive enzymes, kidney function, reproductive system,
and lactation, etc
• in mammals, the secretion of the hormones is controlled by anterior
lobe of the pituitary gland located at the base of the brain
• These hormones are then carried to other gland, such as adrenal cortex
and sex glands to stimulate the production of other hormones
Classification of hormones
• on the basis of structure and composition, hormones are classified into
the following types
• 1) steroid hormones- these hormones are composed of steroid nucleus
having the following structure

• these are mostly secreted by testes and adrenal context of males,

and hence called as adrenal Cotex hormones or sex hormones
• Example of these hormones are androgen , testosterone, and
dihydrotestisterone
• These hormones are stimulant of male sex characteristic
• in females, sex hormones are oestrogens. They are produced by
ovaries.
 • 2) polypeptide hormones- these hormones are polypeptide
• These hormones are secreted by the posterior lobe of the pituitary
gland. Example oxytocin , vasopressin
• 3) amino hormones: these are water soluble hormones containing
amino groups. These are derived from amino acids, example
thyroxine and adrenaline.

Nucleic acid
• the particle in nucleus of the cell responsible for heredity are called
chromosomes, which are made up of proteins, and another type of bio
molecules called nucleic acids
• These are mainly of two types, DNA and RNA
• Since nucleic acids are long chain polymers of nucleotides, so there are
also called polynucleotide
• DNA contains four bases viz adenine, guanine, cytosine, and
Thymine
• RNA also contains four basis. The first three basis are same as in
DNA, but the fourth one is uracil

Structure of nucleic acid

• a unit formed by the attachment of a base to one position of sugar is
known as nucleoside
• in nucleosides, the sugar carbon are numbered as 1, 2, 3 etc. In order to
distinguish these from bases
• When nucleoside is linked to phosphoric acid at five position of sugar
moiety , we get a nucleotide
Thank you!!