Principles of Biotechnology, Practice Problems and FAQs

You must have heard of Captain America, right? The first Avenger in the world of comics. Well the story goes that Captain America was not always the strong and invincible soldier that we know him as. In fact he was quite the opposite. He was injected with a revolutionary serum prepared by a scientist in order to turn him into a super strong soldier who could serve the army and his country during the second world war. This technique used by scientists to alter the genetic makeup of an individual and develop a being who can be useful to the human race, is one of the few premises of biotechnology. However, generating superhumans using biotechnology is a far-fetched idea and is only restricted to the world of fiction, as of now.

So what is biotechnology? Biotechnology is the technique of using living organisms, their components or biological processes to generate products and services that can be useful to human beings.

Did you know that the curd that you eat with parathas or rice is a product of biotechnology! The crispy dosa or the fluffy idli that you have for breakfast are also products of biotechnology! Other examples include bread, cheese, wine, beer. Well, if we start listing, the list of biotechnology products can go on and on. You must be wondering, “But isn’t biotechnology a modern scientific approach?”. Well no, it isn’t. These household examples of biotechnology aren’t recent discoveries, they have been around for thousands of years. In fact, traditional biotechnology dates back to around 10,000 years ago.


                                                     Fig: Products of biotechnology

But during those times, biotechnology was slightly different from today’s trend. Traditional biotechnology was more about the science of using living organisms or their products for the benefits of humans and surroundings. In addition to this, modern biotechnology also involves techniques and processes used for manipulation of genetic material of living organisms so that they can be used for the benefits of the human kind. In this article we will talk about the different principles of biotechnology.

Table of contents

• Traditional biotechnology
• Modern biotechnology
• Principles of modern biotechnology
• Recombinant DNA Technology
• Practice Problems
• FAQs

Traditional biotechnology

Traditional biotechnology dates back to 10,000 years ago when man started selective breeding. With the help of selective breeding, humans could procure plants and livestock of improved quality like good yield, disease resistance etc. So what is selective breeding? It is the process of selecting animals with desired characteristics and then artificially breeding them to obtain a progeny which has desired characteristics of both the parents.

The big hefty hens that we see in poultry farms in the present days are known to have evolved from jungle fowl as a result of selective breeding. Suppose there is a jungle fowl which is skinny and lays more eggs and another variety of hen which lays very few eggs but is hefty and can produce more meat. These varieties can be artificially bred to obtain progenies with both the desirable traits. The genome of progeny will now have both the desirable genes accumulated. Progenies with desired characters are again selected and then bred again. 


                                                          Fig: Selective breeding

Over many generations, desired genes get accumulated and hence organisms of desired characters are obtained. As, selective breeding modifies genome of organisms, it is considered to be a technique of traditional biotechnology.

But you must now be wondering how curd making, preparation of dosa batter, cheese, bread, wine, etc be considered as methods of traditional biotechnology? If you think hard, you will realise that all these processes require the use of microbes and the scientific knowledge of the action of these microbes which can yield favourable results. Thus, these are considered to be methods of traditional biotechnology. In fact, the discovery of vaccines and discovery of antibiotics were also major landmarks in the field of traditional biotechnology.

However, traditional biotechnology has some limitations. For example, during selective breeding both desired and undesired genes are inherited which can lead to accumulation of undesirable genes too. 


                                              Fig: Accumulation of undesirable genes

This limitation can be overcome by modern biotechnology which allows us to specifically introduce desirable genes into organisms.

Modern Biotechnology

In modern times, the term biotechnology is used in a more restricted sense and refers only to those processes which use genetically modified organisms to procure products and services, beneficial to mankind, on a larger scale. Apart from this, other processes such as production of test-tube baby using in vitro fertilisation, designing a synthetic gene and using it, developing a DNA vaccine or correcting a defective gene are also included under biotechnology.

The definition of biotechnology, as given by European Federation of Biotechnology (EFB) encompasses both the traditional view and modern approach towards biotechnology. According to the EFB biotechnology is -

‘The integration of natural science and organisms, cells, parts thereof, and molecular analogues for products and services’.

Now let’s see what are the principle methods of modern biotechnology.

Principles of Modern Biotechnology

Modern biotechnology is devised on two principles- Genetic engineering and bioprocess engineering.


                                                 Fig: Principles of modern biotechnology

Genetic Engineering

Genetic Engineering is the technique to alter the genetic material of an organism to change its genotype and phenotype.

Consider an organism that has a gene, which codes for a certain amino acid sequence.


               Fig: Protein produced by an organism with their normal genes

Using genetic engineering we can introduce new nucleotides in the genome of organisms. This changes the genotype of the organism. Such a modification results in a different amino acid sequence and thereby the alteration of the proteins.


                                 Fig: Introduction of new nucleotides in the genome

This in turn can change the phenotype of the organism. Such an organism is called a genetically modified organism. Thus genetic engineering can create GMOs.


                                       Fig: GMO

Bioprocess engineering

The second principle of modern biotechnology is bioprocess engineering. Bioprocess engineering involves the maintenance of sterile conditions during chemical engineering processes to specifically allow the growth of only desired microbes to obtain pure products. Bioprocess engineering mainly deals with manufacture of biotechnological products using genetically modified organisms.


                                         Fig: Desired product obtaining from GMO

Suppose a desired protein obtained due to change in genotype of a genetically modified organism has some medicinal application. Then we would need to obtain this protein in large amounts. This is where bioprocess engineering comes into picture. Bioprocess engineering helps in maintaining the sterile conditions so that genetically modified organisms grow and multiply. Later the product is obtained from these organisms.


                                                Fig: Process of bioprocess engineering

History of insulin

Today diabetes is one of the most common disorders that people are suffering from. For people suffering from severe diabetes, the only way to handle it is by undergoing insulin therapy. Insulin is usually injected in the fat under your skin using a syringe.

Originally the insulin was produced from the pancreas of sheep and pig. But this had many problems, one of which was that animal insulin often caused allergies in humans who took it. Moreover, huge number of sheep had to be slaughtered to get a few milligrams of insulin. This demand could not be fulfilled. 


                                                   Fig: Traditional way to produce insulin

Hence scientists started thinking why not produce human insulin within bacteria? This would not only solve the problem of allergies but will also allow large scale production in less time as bacteria multiplies rapidly. This would help to fulfil the insulin demands.


                                               Fig: Bacteria

But bacteria cannot produce human insulin on its own. So how can we achieve this target? Well genetic engineering can be helpful here. We can use one of the methods of genetic engineering, known as recombinant DNA technology, to obtain human insulin from bacteria.

Recombinant DNA Technology 

The technology used for introducing DNA sequence from one organism to another is known as recombinant DNA technology or RDT.

Demonstration of rDNA technology was first done by Stanley Cohen and Herbert Boyer in 1972. 
 

These scientists came up with an idea of combining DNA of two different organisms. Let’s see how they did it!!

Cohen and Boyer showed that it is possible to combine the genome of two different organisms.

They chose two different bacteria to perform this experiment. One of the bacteria was E.coli and the other was Salmonella typhimurium. 


                                         Fig: Bacteria taken for the experiment

Both E. coli and Salmonella have circular extrachromosomal DNA known as plasmid. Plasmid is different from normal nucleoid DNA and can replicate on its own, independent of the chromosomal DNA, as it has the DNA sequence which serves as the origin or replication (ori). While every bacteria has nucleoid DNA, not all of them have plasmid DNA. Some can have both plasmid and nucleoid DNA. 


                                 Fig: Salmonella typhimurium

The plasmid of Salmonella has genes which provide resistance against many types of antibiotics. Cohen and Boyer came up with an idea of transferring antibiotic resistance genes to E.coli. 


                        Fig: Salmonella typhimurium with antibiotic resistance gene

To do that, first they had to cut the part of the plasmid DNA of Salmonella which was responsible for antibiotic resistance. Boyer found that certain enzymes can act as molecular scissors and cut DNA at specific locations. Such enzymes are called restriction enzymes. 


                    Fig: Cutting the antibiotic resistance gene with restriction enzyme

They used the same restriction enzyme to cut the plasmid DNA of E. coli. Then the two DNA fragments were linked using the enzyme DNA ligase. This makes a new combination of circular DNA created in vitro and is known as recombinant DNA.


                                   Fig: Formation of rDNA

Thus Cohen and Boyer had successfully constructed the first ever Recombinant DNA. This was an important milestone in the history of modern biotechnology. 

This recombinant DNA upon transfer into E. coli can replicate on its own due to presence of an origin of replication sequence in the E. coli plasmid and thus can make multiple copies of the antibiotic resistance gene of Salmonella. The E. coli plasmid DNA in this case acts as a vector which carries the foreign DNA (antibiotic resistance gene of Salmonella) into the host cell (E. coli). The process of making multiple copies of a gene by inserting it into a host cell via a vector is known as gene cloning.


                                                      Fig: Recombinant E Coli

Steps of rDNA Technology

There are three main steps for the rDNA technology. They are: identification of DNA with desirable genes, introduction of the identified DNA into the host and maintenance of introduced DNA in the host and transfer of the DNA.


                                                     Fig: Steps of rDNA technology

The first step would be to identify and isolate desirable genes. Suppose, insulin is the desired protein, which needs to be produced in bacteria. So our desired gene would be the gene coding for insulin. Insulin gene is extracted from human cells.


                                Fig: Insulin extraction from human cell

The second step is to introduce the identified DNA into host bacteria with the help of a suitable plasmid vector DNA.


                              Fig: rDNA is introduced into the host organism

Third step will be maintenance of introduced recombinant DNA in the host and transfer of the DNA to its progeny. Sometimes there is a chance of recombinant DNA getting degenerated. Hence this step is carried out to ensure that recombinant DNA sustains inside the bacteria and is transferred to its progeny.


                                       Fig: Transfer of rDNA into progenies

Practice Problems

Q 1. How many of the statements below are incorrect?

A. The gene of interest and vector DNA is joined using DNA ligase

B. The first recombinant DNA was created using the plasmid isolated from Escherichia coli.

C. It is not necessary for a plasmid vector to have an ori sequence.

D. Stanle and Cohen coined the term biotechnology.

a. 1
b. 2
c. 3
d. 4

Answer: In 1919, Hungarian engineer Karl Ereky coined the term "biotechnology," for the processes which involve the use of living organisms to obtain products and services that are useful to mankind. As a result, statement four is false.

Hence the correct option is a.

Q 2. Assertion (A): Bioprocess engineering mandatorily requires the maintenance of sterile conditions.
Reason (R): The term ‘sterile’ here refers to the inability to reproduce.

a. Both A and R are true and R is the correct explanation of A
b. Both A and R are true but R is not the correct explanation of A
c. A is true but R is false
d. Both A and R are false

Answer: Bioprocess engineering is concerned with the creation and design of manufacturing equipment and processes that can be used for the large-scale production of biological products. In bioprocess engineering, maintaining sterile conditions is essential for avoiding contamination and allowing the growth of only the necessary cells in large quantities for the production of various biological products. The term sterile here refers to an environment that is free of microorganisms such as bacteria, fungi, and their spores. It is necessary to avoid any chances of degradation or contamination of products. The term ‘sterile' is used in reproductive physiology to describe a person who is unable to reproduce.

Hence the correct option is c.

Q 3. In E.coli, a plasmid isolated from Salmonella is inserted.
Which of the following enzymes is used by the plasmid to replicate within E.coli?

a. RNA polymerase
b. Restriction enzymes
c. Nucleases
d. DNA polymerase

Answer: DNA replication helps in synthesising identical copies of DNA within cells. DNA polymerase is responsible for replicating DNA strands by using the parental strand as template and synthesising a complementary strand by joining respective nucleotides with the help of phosphodiester bonds. Thus the plasmid obtained from Salmonella replicates within E.coli using the DNA polymerase enzyme.

Hence the correct option is d.

Q 4. Which of these problem(s) connected with traditional hybridisation techniques can be resolved using genetic engineering?

a. Traditional hybridisation procedures might result in the introduction and accumulation of undesirable genes along with the desired genes
b. Traditional hybridisation procedures always lead to elimination of desired genes 
c. Hybrids produced through traditional hybridisation may or may not have all the desired traits
d. Both a and c

Answer: Traditional hybridisation is a type of human-mediated hybridisation performed in plant and animal breeding that frequently results in the introduction and accumulation of undesired genes along with desired genes of interest. As a result, traditional hybridisation does not guarantee that the hybrids (offspring) produced will have all of the desired features. Genetic engineering used in modern biotechnology allows us to identify and introduce only one or a set of desirable genes of interest into the target organism without introducing undesirable ones.

Hence the correct option is d.

FAQs

Q 1. What are the new products of biotechnology?
Answer: DNA hard drives, DNA origami, artificial intelligence in medicine, and aptamer biosensors are examples of emerging biotechnology products. DNA molecules are employed as a storing material in DNA hard drives. DNA data will not be stored in binary numbers like today's optical and magnetic storage methods (i.e., 1s and 0s). They would instead be kept as DNA nucleotide bases (A, C, G, and T). DNA origami is the folding of DNA at the nanoscale to construct arbitrary two- and three-dimensional shapes. Through the design of its base sequences, the specificity of interactions between complementary base pairs makes DNA a desirable construction material. Aptamer-based, mass-sensitive biosensors, such as evanescent wave-based sensors (e.g., surface-plasmon resonance), are a type of label-free bioassay.

Q 2. What is the most prominent product on the market that is a typical biotech product?
Answer: Soybean is the most economically important oil crop on the planet. Its beans have a higher amount of vital amino acids than meat, making it one of today's most significant food crops. Soybeans that have been processed are used in a variety of foods. Given that biotechnology is used in 81 percent of the world's soybeans, it helps farmers to produce soybeans more profitably, develop unique frying oils, and implement current farming practises for soil conservation. . The majority of GMO soy is used to feed animals, mostly poultry and livestock, as well as to make soybean oil. It's also employed in processed meals as an ingredient (lecithin, emulsifiers, and proteins).

Q 3. Do GMOs have an impact on the environment?
Answer: According to research, GM crop technology can lead to an increase in herbicide use and the spread of herbicide-resistant weeds. Furthermore, there is concern that using GM crops will have a harmful influence on the agriculture ecology.

Q 4. Why are Hela cells significant in the field of biotechnology?
Answer: HeLa cell, a malignant cell from a strain that has been grown continuously since its isolation in 1951 from a patient with cervical carcinoma. The word HeLa comes from the patient's name, Henrietta Lacks. These remarkable cells, dubbed "HeLa" cells, are now utilised to study the impact of poisons, medicines, hormones, and viruses on cancer cell proliferation without having to test them on humans.

YOUTUBE LINK:  https://www.youtube.com/watch?v=qSeuqV_lDwY 

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