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Biotechnology
Biotechnology is the use of living systems and organisms to develop or make useful products, or
"any technological application that uses biological systems, living organisms or derivatives
thereof, to make or modify products or processes for specific use" (UN Convention on Biological
Diversity, Art. 2).
Biotechnology has applications in four major industrial areas, including health care (medical), crop
production and agriculture, non-food (industrial) uses of crops and other products (e.g.
biodegradable plastics, vegetable oil, biofuels), and environmental uses.
Proteins
Proteins are large biological molecules, or macromolecules, consisting of one or more long chains
of amino acid residues.
Of all the molecules encountered in living organisms, proteins have the most diverse functions,
as the following list suggests.
1. Catalysis. Catalytic proteins called the enzymes accelerate thousands of biochemical
reactions in such processes as digestion, energy capture, and biosynthesis.
2. Structure. Structural proteins often have very specialized properties.
3. Movement. Proteins are involved in all cell movements.
4. Defense. A wide variety of proteins are protective.
5. Regulation. Binding a hormone molecule or a growth factor to cognate receptors on its
target cell changes cellular function.
6. Transport. Many proteins function as carriers of molecules or ions across membranes or
between cells.
7. Storage. Certain proteins serve as a reservoir of essential nutrients.
8. Stress response. The capacity of living organisms to survive a variety of abiotic stresses
is mediated by certain proteins.
Amino Acids
Proteins can be distinguished based on their number of amino acids (called amino acid
residues), their overall amino acyl composition, and their amino acid sequence. Molecules with
molecular weights ranging from several thousand to several million Daltons are called
polypeptides. Those with low molecular weights, typically consisting of fewer than 50 amino
acids, are called peptides.
Plants and bacteria can synthesize all 20 of the amino acids. Whereas, humans cannot synthesize
9 of them. These nine amino acids must come from our diets and are called essential amino acids.
The essential amino acids are: Histidine, Isoleucine, Leucine, Lysine, Methionine,
Phenylalanine, Threonine, Tryptophan and Valine.
The 20 Amino Acids
Carbohydrates
A carbohydrate is a large biological molecule, or macromolecule, consisting of carbon (C),
hydrogen (H), and oxygen (O) atoms, usually with a hydrogen: oxygen atom ratio of 2:1 (as in
water); in other words, with the empirical formula Cm(H2O)n (where m could be different from n).
Carbohydrates are technically hydrates of carbon; structurally it is more accurate to view them as
polyhydroxy aldehydes and ketones.
The term is most common in biochemistry, where it is a synonym of saccharide. The
carbohydrates (saccharides) are divided into four chemical groups:
monosaccharides
disaccharides
oligosaccharides
polysaccharides.
Like
most classes of biological molecules, carbohydrates occur as both monomers and polymers.
Small carbohydrates are called sugars, which commonly include monosaccharides (single
sugars) and some disaccharides (two sugars linked together). Larger carbohydrates are called
polysaccharides (many sugars linked together).
Monosaccharides
These are the only sugars that can be absorbed and utilized by the body. Disaccharides and
polysaccharides must be ultimately broken down into monosaccharides in the digestive process
known as hydrolysis. Only then can they be utilized by the body. Three monosaccharides are
particularly important in the study of nutritional science: glucose, fructose and galactose.
1. Glucose (also known as dextrose or grape sugar)
This monosaccharide is the most important carbohydrate in
human nutrition because it is the one that the body fuses directly
to supply its energy needs. Glucose is formed from the hydrolysis
of di- and polysaccharides, including starch, dextrin, maltose,
sucrose and lactose; from the monosaccharide fructose largely during absorption; and from both
fructose and galactose in the liver during metabolism. Glucose is the carbohydrate found in the
bloodstream, and it provides an immediate source of energy for the body’s cells and tissues.
Glucose is also formed when stored body carbohydrate (glycogen) is broken down for use.
2. Fructose (also known as levulose or fruit sugar)
Fructose, a monosaccharide, is very similar to another
monosaccharide, galactose. These two simple sugars share the
same chemical formula; however, the arrangements of their
chemical groups along the chemical chain differ. Fructose is the
sweetest of all the sugars and is found in fruits, vegetables and the nectar of flowers, as well as
in the unwholesome (to humans) sweeteners, molasses and honey.
3. Galactose
Galactose differs from the other simple sugars, glucose and fructose, in
that it does not occur free in nature. It is produced in the body in the
digestion of lactose, a disaccharide.
Disaccharides
Disaccharide, also called Double Sugar, any substance that is composed of two molecules of
simple sugars (monosaccharides) linked to each other.
Disaccharides are formed when two monosaccharides are joined together and a molecule of
water is removed, a process known as dehydration reaction. For example; milk sugar (lactose) is
made from glucose and galactose whereas the sugar from sugar cane and sugar beets (sucrose)
is made from glucose and fructose.
1. Sucrose
The disaccharide, sucrose, consists of one molecule of each
of two monosaccharides—glucose and fructose. Sucrose is
found in fruits and vege ables and is particularly plentiful in
sugar beets (roots) and sugarcane (a grass). Refined white
and brown sugars are close to 100% sucrose because
almost everything else (including the other kinds of sugars present, the vitamins, the minerals and
the proteins) have been removed in the refining process.
2. Maltose (also known as malt sugar)
This disaccharide, unlike sucrose, is not consumed
in large amounts in the average American diet. It is
found in malted cereals, malted mi lks and sprouted
grains.
Maltose occurs in the body as an intermediate
product of starch digestion. (Starch is a
polysaccharide.) When maltose is hydrolyzed, it
yields two molecules of glucose.
3. Lactose (also known as milk sugar)
This disaccharide is found only in milk. Human milk
contains about 4.8 g per 100 ml and cow’s milk
contains approxim ately 6.8 g per 100 ml. When
lactose is hydrolyzed it yields one unit of the
monosaccharide glucose and one unit of the
monosaccharide galactose.
Polysaccharides
Polysaccharides are polymeric carbohydrate structures, formed of repeating units (either mono-
or di-saccharides) joined together by glycosidic bonds. These structures are often linear, but may
contain various degrees of branching.
Polysaccharides have a general formula of Cx(H2O)y where x is usually a large number between
200 and 2500. Considering that the repeating units in the polymer backbone are often six-carbon
monosaccharides, the general formula can also be represented as (C6H10O5)n where 40 ≤ n ≤
3000.
1. Starch
Starch is abundant in the plant world and is
found in granular form in the cells of plants.
Starch granules can be seen under a microsc
ope and they differ in size, shape and
markings in various plants.
2. Dextrin
There are several “varieties” of this
polysaccharide. Dextrins are most commonly
consumed in cooked starch foods, as they are
obtained from starch by the action of heat.
Dextrins are intermediary products of starch
digestion, also, and are formed by the action of amylases on starches. They render the disaccha
ride maltose on hydrolysis.
3. Glycogen
Glycogen is the reserve carbohydrate in humans. It
is to animals as starch is to plants. Glycogen is very
similar to amylopectin, having a high molecular
weight and branched-chain structures made up of
thousands of glucose molecules.
The main difference between glycogen and
amylopectin is that glycogen has more and shorter branches, resulting in a more compact,
bushlike molecule with greater solubility and lower viscosity (less stickiness or gumminess).
4. Cellulose
Like starch and glycogen, cellulose is composed of th
ousands of glucose molecules. It comprises over
50% of the carbon in vegetation and is the structural
constituent of the cell walls of plants.
Cellulose is, therefore, the most abundant naturally-
occurring organic substance. It is characterized by its insolubility, its chemical inertness and its
physical rigidity.
Lipids, Fats and Steroids
Lipids
Lipids are group of naturally occurring compounds, which have in common a ready solubility in
such organic solvents. They include a diverse range of compounds, like fatty acids and their
derivatives, carotenoids, terpenes and terpenoids, steroids and bile acids.
Table 1. Classification of Lipids
Lipids Description Types/
Classification
Examples /
Derivatives
Fatty Acids
-compounds
synthesized in
nature
via condensation
of malonyl
coenzyme
-usually contain
even numbers of
carbon atoms in
straight chains
(commonly C14
to C24)
1.
2.
3. 1. Saturated Fatty
Acids - triglycerides
4. contain the
maximum possible
amount of
hydrogens
5.
2. Unsaturated fatty
Acids - they’re not
bonded to as many
6. hydrogens as they
could if they weren’t
Lauric Acid
Myristic Acid
Palmitic Acid
Stearic Acid
Linoleic Acid
Oleic Acid
Capric Acid
- -Fatty acids are
usually derived
from triglycerides
or phospholipids
-When they are
not attached to
other molecules,
they are known
as "free" fatty
acids.
double bonded to
each other
Terpenes and
Terpenoids
- group of
molecules whose
structure is based
on a various
but definite
number of
isoprene units
-The difference
between terpenes
and terpenoids is
that terpenes are
hydrocarbons,
whereas
terpenoids
contain
additional functio
nal groups
Vitamin A
Aroma used
in Perfumery
Primary
constituents of
essential oils
from plants
and flowers
Natural flavor
additives for
food
Steroids
-type of organic
compound that
contains a
characteristic
arrangement of
four cycloalkane r
ings joined to one
another
Sex
hormones,
Testosterone
and Estradiol
Adrencortical
hormones
D vitamins
Bile acids
Cardiac
Poisons
Cholesterol
-lipid with a
unique structure
consisting of four
linked
hydrocarbon rings
forming the bulky
steroid structure
-known as a
"sterol" because it
is made out of
an alcohol and
steroid.
------------------------ ------------------
Sex Hormones
(Steroid Hormones)
-steroid hormones
are all derived
from cholesterol
- they all contain
the same
cyclopentanophe
nanthrene ring
Important
mammalian
hormones are
shown below
------------------
and atomic
numbering
system as
cholesterol
- Steroid
hormones with 21
carbon atoms are
known
systematically as
pregnanes,
whereas those
containing 19 and
18 carbon atoms
are known as
androstanes and
estranes,
respectively.
Question
1. Protein can be distinguished based on its ________________.
a. Amino Acid
b. Amino Acid Residues
c. peptides bonds
d. number of carbons
Answer: B. Amino Acid Residues - can be distinguished based on their number of amino acids,
their overall amino acyl composition, and their amino acid sequence.
2. Polysaccharides can be broken down into monosaccharaides by means of
______________.
a. Digestion and Hydrolysis
b. Heating
c. Enzymatic Hydrolysis
d. Hydrolysis
Answer: D. Hydrolysis – used to degrade the glucose from the cellulosic structure of a
biomass.
3. Produced in the body by means of digestion of lactose.
a. Fructose
b. Galactose
c. Glucose
d. Lactose
Answer: B. Galactose - When lactose is hydrolyzed it yields one unit of the monosaccharide
glucose and one unit of the monosaccharide galactose.
4. Also known as Malt Sugar
a. Maltose
b. Lactose
c. Fructose
d. Dextrin
Answer: A. Maltose - Maltose occurs in the body as an intermediate product of starch
digestion.
5. ___________: Animals; Starch: Plants
a. Dextrin
b. Glycogen
c. Cellulose
d. Glucose
Answer: B. Glycogen - Glycogen is the reserve carbohydrate in humans. It is to animals as
starch is to plants. Glycogen is very similar to amylopectin, having a high molecular weight
and branched-chain structures made up of thousands of glucose molecules.
6. The following are important derivatives of steroid except:
a. Vitamin A
b. Vitamin D
c. Bile Acids
d. None
Answer: A. Vitamin A – Vitamin D, Bile Acids are some important derivatives from steroid,
Vitamin A is not included.
7. Lipid with a unique structure consisting four linked hydrocarbon rings forming the bulky
steroid structure
a. Cardiac Poisons
b. Bile Acid
c. Cholesterol
d. Estradiol
Answer: C. Cholesterol – Based on the chemical formula –
8. Most commonly consumed in cooked starch foods.
a. Dextrins
b. Glycogen
c. Glucose
d. Estrogen
Answer: A. Dextrins – Dextrins are most commonly consumed in cooked starch foods, as they
are obtained from starch by the action of heat.
9. Polysaccharides have a general formula of ________________.
a. Cy(H2O)x
b. Cy2(H2O)x
2
c. Cx(H2O)y
d. Cy2(H2O)x
2
Answer: C. Cx(H2O)y – Polysaccharides have a general formula of Cx(H2O)y where x is usually a
large number between 200 and 2500
10. Milk: lactose; Malted Cereals: ____________.
a. Maltose
b. Glucose
c. Sucrose
d. Fructose
Answer: A. Maltose – This disaccharide, unlike sucrose, is not consumed in large amounts in
the average American diet. It is found in malted cereals, malted mi lks and sprouted grains.
11. The sweetest of all the sugars and is found in fruits, vegetables and the nectar of flowers, as
well as in the unwholesome (to humans) sweeteners, molasses and honey.
a. Maltose
b. Glucose
c. Sucrose
d. Fructose
Answer: D. Fructose – Fructose, a monosaccharide, is very similar to another monosaccharide,
galactose. These two simple sugars share the same chemical formula; however, the
arrangements of their chemical groups along the chemical chain differ.
References:
Amino Acids, Peptides and Proteins. Date Retrieved: July 23, 2014
Biotechnology. Date Retrieved: July 23, 2014 from http://en.wikipedia.org/ wiki/ Biotechnology
Carbohydrates. Date Retrieved: July 23, 2014 from http://www.harpercollege.edu/tm-
ps/chm/100/dgodambe/thedisk/carbo/yback2.htm
Introduction: Steroid Hormones. Date Retrieved: July 23, 2014 http://themedical
biochemistrypage.org/steroid-hormones.php
Lipid. Date Retrieved: July 23, 2014 from http://biology.about.com/od/molecular
biology/ss/lipids.htm
Terpene. Date Retrieved: July 23, 2014 from http://en.wikipedia.org/wiki/Terpene
Polysaccharides. Date Retrieved: July 23, 2014 from http://en.wikipedia.org/wiki
/Polysaccharide
Saccharides. Date Retrieved: July 23, 2014 from