Biology For Class X - Chapter No. 8 - Biotechnology - Long Question Answers

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CHAPTER 8: BIOTECHNOLOGY
Long Questions Answers

Q.1: Define biotechnology and describe its importance.
Ans: BIOTECHNOLOGY:
There are several definitions for biotechnology. One simple definition is that:

"It is the commercialization of cell and molecular biology."

According to the National Science Academy of United States:

Biotechnology is the "controlled use of biological agents like cells or cellular components for beneficial use".

It covers both classical as well as modern biotechnology.

Generally, biotechnology can be defined as:

"Biotechnology is technology that utilizes biological systems, living organisms or parts of this to develop or create different products."

OR

"Biotechnology is the branch of applied science that uses living organisms and their derivatives to produce products and processes. These products and processes feature in healthcare, medicine, biofuels, and environmental safety."

OR

"Biotechnology refers to the use of living organisms in systems or processes for the manufacture of useful products for the services of human kind."

Old Biotechnology:
Although the term biotechnology is new but it has been in practice since thousands of years . The initial credit goes to Indo Aryan civilizations who produced fermented foods and medicines. The earliest biotechnologists were farmers who developed improved species of plants and animals using cross-pollination or cross breeding techniques.

Modern Biotechnology:
Genetic engineering is considered as modern biotechnology. It has been defined as:

"The artificial manipulation, modification, and recombination of DNA or other nucleic acid molecules in order to modify an organism or population of organisms. It refers to any process in which an organism’s genome is intentionally altered."

 

Genetic engineering does not encompass traditional breeding techniques because it requires manipulation of an organism’s genes through cloning or transformation via the addition of foreign DNA.

Scope and importance of Biotechnology:
Biotechnology is controlled use of biological agents for beneficial use. It is integrated use of biochemistry, molecular biology, microbiology to achieve technological application of the capabilities of bilogical agents.
The following are the areas of the application of biotechnology:

Biotechnology in medicine:
In the field of medicine biotechnology has been extremely helpful in the production of large number of vaccines and antibodies. The major achievements include:

• Production of a monoclonal antibody, DNA, RNA probes for diagnosis of various diseases.
• Valuable drugs like insulin and interferon have been synthesized by bacteria for the treatment of human diseases.
• DNA fingerprinting is utilized for identification of parents and criminals.
• Development of recombinant vaccines like human hepatitis B etc. by genetically engineered microbes; by genetically engineered microbes.

Biotechnology in Agriculture:
Biotechnology has been beneficial in the field of agriculture in the following ways:

• Plant cell, tissue, and organ culture are used for rapid and economic clonal multiplication of fruit and forest trees.
• They are also used for the production of virus-free genetic stocks and planting material as well as in the creation of novel genetic variations through soma-clonal variation.
• Genetic engineering techniques are utilized to produce transgenic plants with desirable genes like disease resistance, herbicide resistance, an increased shelf life of fruits etc.
• Molecular breeding to hasten the process of crop improvement.

Biotechnology in Industry:
Industrial Biotechnology is an area with which a large number of food products and beverages are being produced on large scale. These include

• Production of alcohol by microorganisms
• Production of antibiotics by microorganisms
• Production of a variety of pharmaceutical drugs and chemicals like lactic acid, glycerine etc. are being produced by genetic engineering for better quality and quantity.
• Fermented foods like pickled and yogurt are produced
• Malted foods like powdered milk are being produced
• Production sof diary products and vitamins

Biotechnology in the environment:
Environmental problems like pollution control, depletion of natural resources for nonrenewable energy, conservation of biodiversity etc. are being dealt with using biotechnology. It is useful in the following ways:

• Bacteria are being utilized for detoxification of industrial effluents.
• Combats oil spills> Bacterial enzymes are used for treatment of sewage.
• Biogas production.
• Bio-pesticides give an environmentally safer alternative to chemical pesticides for control of insects, pest and diseases.
• Bio fertilizers Bio sensors etc.

Q.2: Write a detailed note on Fermentation
Ans: FERMENTATION:
Fermentation is an alternative term for Anaerobic respiration. This term was used by W. Pasteur and he defined it as respiration in the absence of oxygen. It can be define as:

"Fermentation is the process by which living organism such as yeast or bacteria are employed to produce useful compounds or products."

Or

"An important way of making ATP without oxygen is called fermentation."

TYPES OF FERMENTATION:
It has two major types:

1. Alcoholic fermentation
2. Lactic Acid Fermentation

1. ALCOHOL FERMENTATION:
Each pyruvic acid molecule is converted to alcohol and carbon dioxide . It produces ethanol and NAD⁺ from NADH. The NAD⁺ allows glycolysis to continue making ATP.
Ethanol fermentation converts two pyruvate molecules, the products of glycolysis into two molecules of ethanol and two molecules of carbon dioxide.
Cause:
This type of fermentation is carried out by yeast Saccharomyces cerevisiae and some bacteria.
Uses:

• It is used to make bread, wine, and biofuels.
• It also causes the rising of dough in breads. The yeast produces carbon dioxide gas in the dough using alcoholic fermentation. The gas forms bubbles which makes the dough rise and expand. The bubbles leave small holes in the bread after baking which makes the bread light and fluffy.

LACTIC ACID FERMENTATION:
In this fermentation pyruvic acid from glycolysis changes to lactic acid. In this process, NAD⁺ forms NADH. NAD⁺ in turn, lets glycolysis continue.
Cause:
This type of fermentation is carried out by the bacteria Streptococcus and Lactobacillu species for souring milk into yogurt and production of various types of cheese.
Uses:

• Produce yogurt and various types of cheese.
• It is also used by our own muscle cells when we work them hard and fast.

Fermentation or Industrial Biotechnology:
Fermentation can be referred to as industrial biotechnology because it refers to the growth of micro organisms forming on food under aerobic or an aerobic conditions with the aim of optimizing the growth of organism for the production of targeted microbial products such as cheese, yogurt, fermented pickles and sausages, soy sauce, beverages (beers, wines etc.) and spirit etc.

Applications of Fermentation:

APPLICATION IN MEDICINE

• Production of antibiotics
• Production of insulin
• Production of growth hormones
• Production of vaccines
• Production of interferon

APPLICATION IN THE FOOD INDUSTRY

• Production of fermented foods as cheese, wine, beer, and bread to high-value products
• Food grade bio preservatives
• Functional foods / Neutraceuticals
• Production of single-cell protein
• Pasteurization
• Packaging

OTHER APPLICATIONS:
It is also used for waste management such as biofuels production (biodiesels, bioethanol, butanol, biohydrogen, etc).
It is also used to produce bio-surfactant, polymers production such as bacterial cellulose production. Development of bioremediation processes (involving microbes or their isolated enzymes) for soils and waste water treatments.

Fermentation as a food preservative technique:
Fermented foods are foods that have been prepared in a way so that the bacteria naturally found within them starts to ferment. Lacto-fermentation, is a chemical process in which bacteria and other micro-organisms break down starch and sugars within the foods, possibly making them easier to digest, and resulting in a product that is filled with helpful organisms and enzymes. This process of fermentation is a natural preservative, which means that fermented foods can last a long time.

Food products of fermentation

• Dairy products: Yogurt, cheese
• Cereal products: bread ,cakes
• Fruit and vegetable products: flavorings , candy, fruit juice, silage
• Beverages: beer, wine, cider
• Pickling: pickling of beans , onions, cauliflower, cucumber, tomatoes cabbage

Non Food products created by fermentation:

• Antibiotics
• Laundry detergents
• Insulin, growth hormones
• Cellulose
• Monoclonal antibodies
• Compost
• Chemicals and
• Medicines to dissolve tumors and to clot blood.

Q.3: What is fermentor and its advantages?
Ans: Fermentation:
In modern biotechnology, the term fermentation means the large-scale production of any product by the massive culture (population) of microorganisms.

Fermentor:
In general term, as its name suggests:

"Fermenrtors are containers used to grow bacteria and fungi on large scale."

Or

“A fermentor is an enclosed and sterilised vessel that maintains optimal conditions for the growth of a microorganism.”

Or

“Fermentor is a large container in which populations of microorganisms are grown to produce large quantities of products.”

The general idea behind:

"The fermentor is to provide a stable and optimal environment for microorganisms to reproduce and interact with subtrate for required product."

Advantages Of Fermentor:

1. Fermentors have an auto control system so environmental changes cannot harm microbial growth.
2. Separation of products is easy and safe.
3. Inoculation of microbes is easy.
4. Wastage of materials in handling is minimized by fermentors.
5. They can be installed with ease and take up very little space.
6. Single fermentors can be used for the production of a wide range of products.
7. Fermentors enable the production of medical products, such as penicillin, Insulin, Erythromycin, Streptomycin, Griseofulvin (Antifungal antibiotic) and hundreds of other products from microbes.
8. Fermentors (bioreactors) provide a suitable environment (temperature and pH etc.) for quick metabolism in microorganisms.
9. It provides a specialized medium in which all essential nutrients of microorganisms are present. When the raw material is added to the medium, microorganisms carry out metabolic reactions to make products.
10. Fermentors are used for the manufacture of many products e.g. medicines (Antibiotics), vaccines, interferon, hormones etc.

Q.4: Why genetic engineering is considered as modern biotechnology. Explain?
Ans: GENETIC ENGINEERING:
Definition:
Genetic engineering is considered as modern biotechnology. It has been defined as:
"The artificial manipulation, modification, and recombination of DNA or other nucleic acid molecules in order to modify an organism or population of organisms. It refers to any process in which an organism’s genome is intentionally altered."

Explanation:
ROLE OF GENETIC ENGINEERING IN BIOTECHNOLOGY:
Genetic engineering play important role in biotechnology. Such as:
1. cloning:
Genetic engineering does not encompass traditional breeding techniques because it requires manipulation of an organism’s genes through cloning or transformation via the addition of foreign DNA.
For example, a DNA fragment may be isolated from one organism spliced to other DNA fragments, and put into a bacterium or another organism. This process is called cloning because many identical copies can be made of the original DNA fragment.

2. Production Of insulin:
In 1970s, the scientists were able to alter the DNA of the organisms and in 1978 the first genetically engineered drug, human insulin was produced by bacteria.

3. Vitro Mutagenic Methods.
In another example of genetic engineering, a stretch of DNA, often an entire gene, may be isolated and its nucleotide sequence determined, or its nucleotide sequence may be altered by in vitro mutagenic methods. The related activities in genetic engineering have two basic objectives:
To learn more about the ways nature works, and
To make use of this knowledge for practical purposes.
A useful genetic approach to increase the efficiency of production.

Fermentation:
The fermentation was useful in its production and genetic engineering promises to make the fermentation process economically competitive.

There are several ways that DNA can be cut, spliced or otherwise altered. But engineered DNA by itself is a static molecule. To be anything more than the end of a laboratory exercise, the molecule must be integrated into a system of production; to have an impact on society at large; it must become a component of an industrial or otherwise useful process.

Q.5: What is HGP? Write down its objectives?
Ans: HGP Or Human Genome Project:
In 1990, The Human Genome Project was launched to map all the genes of the human cell. The complete draft of the human genome sequence was published in 2002.
OBJECTIVES:
It has following objectives:

• Determining the human DNA sequence.
• Understanding the function of the human genetic code>
• Identifying all of the genes.
• Determining their functions Understanding how and when genes are turned on and off throughout the lifetime of an individual.

Q.6: Write down uses of genetic engineering? Also describe its tool along with the major achievements in the field of biotechnology.
USES OR IMPORTANCE OF GENETIC ENGINEERING:
Genetic engineering is the cornerstone of modern biotechnology. It is based on scientific tools which enable the researchers to:

• Identify the gene that produces the protein of interest.
• Cut the DNA sequence that contains the gene from a sample of DNA.
• Place the gene into a vector, such as a plasmid or a bacteriophage.
• Use the vector to carry the gene into the DNA of the host cells, such as escherichia coli (E coli) or mammalian cells grown in culture.
• Induce the cells to activate the gene and produce the desired protein.
• Extract and purify the protein for therapeutic use.

GENETIC ENGINEERING TOOLS
To manipulate cells and DNA, scientists use tools that are borrowed from nature. These include:

• Restriction enzymes:
  These naturally occurring enzymes are used as a defense by bacteria to cut up DNA from viruses. There are hundreds of specific restriction enzymes that researchers use like scissors to snip specific genes from DNA.
  
  
• DNA Ligase:
  This enzyme is used in nature to repair broken DNA. It can also be used to paste new genes into DNA.
  
  
• DNA vector:
  
  “In molecular cloning, a vector is a DNA molecule used as a vehicle to artificially carry foreign genetic material into another cell, where it can be replicated.”
  The gene of interest is attached to a suitable vector (cloning vehicle), to carry the gene to the host organism.
  Plasmids:
  The most common vector used in genetic engineering is a plasmid. It is the extra-chromosomal circular DNA of E.coli. These are mostly circular units of DNA. They can be engineered to carry genes of interest.
  
  Bacteriophages (also known as phages):
  Bacteriophages (viruses that can enter or infect bacteria) are also used as vectors. The DNA of the vector is cut into fragments by the restriction endonucleases. Using the enzyme DNA ligase, the DNA fragments of the donor and vector are joined together. As a result, recombinant DNA is obtained.
  
  
• Recombinant DNA technology:
  
  "When segments of DNA are cut and pasted together to form new sequences ,the result is known as recombinant DNA."
  “Recombinant DNA technology involves the selection of DNA of one organism (donor) and its introduction (insert) to combine with the DNA of another organism (recipient)."
  The cells use this modified blueprint and their own cellular machinery to make the protein encoded by a recombinant DNA.
  As a result, the recipient organism acquires the genetic abilities of the donor and is called the Genetically Modified Organism (GMO) or transgenic cells .
  
  "The DNA that is a combination of genes from two different sources is called recombinant DNA.”
• The GMO contains genes of interest and manufactures the desired products.
  
  

Bacterial cells have different kinds of enzymes. Some of these can cut DNA into fragments and others can join such fragments.

MAJOR ACHIEVEMENTS OF GENETIC ENGINEERING:
Genetic engineering means making changes to DNA in order to change the way living things work. So many things have been made through genetic engineering such as; Vaccines, Monoclonal antibodies, Gene therapy, Interferons, Interleukins, Recombinant human proteins, Human growth hormones, Clotting factors and Erythropoietins. Such as:

1. Human insulin:
   Human insulin was the first genetic engineering product. In 1982, the human gene for insulin was inserted into an E. coli bacterium. Since then, the modified bacteria are providing large amounts of human insulin, which scientists and doctors can collect and use.
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2. Hepatitis B vaccine:
   A vaccine against hepatitis B virus has been produced from yeast through genetic modification.
   
   
3. Human growth hormone:
   Human growth hormone was produced in genetically modified bacteria. It is used to treat dwarfism.
   
   
4. Interferon:
   Interferon (anti-virus protein) is made in genetically modified bacteria.
   
   
5. Vaccine against foot and mouth disease: A vaccine against foot and mouth diseases are being developed for foot-and-mouth disease, a highly contagious viral disease that infects cattle, sheep, and other animals. The trick was to carve up the virus genome to make a DNA copy that codes only for the three capsid proteins. 
   
   
6. Vaccine against coccidiosis:
   A vaccine against coccidiosis (a parasitic disease of both invertebrates and vertebrates caused by parasitic protozoa which invade the epithelial cells lining the alimentary tract and the cells of associated glands.). A vaccine made against coccidiosis by using avian protein to immunize chicken against avian coccidia. This vaccine kills protozoan that causes coccidiosis.
   
   
7. Treatment of Trypanosomiasis:
   Treatment of trypanosomiasis (sleeping sickness) may be possible through the use of biotechnological techniques. Trypanosomiasis is a parasitic infection and caused by a parasite called Trypanosoma brucei in humans and other animals. Genetic engineers are doing research to develop such proteins which can kill the parasite of this disease.
   
   
8. Gene therapy:
   Molecular biology has introduced in modern medicine a new way to cure diseases, namely genetic therapy. Gene therapy enables the treatment of genetic disorders. Through this technique, genetic engineers treat genetic disorders by introducing a gene into the patient’s cells. It is being used to treat genetic disorders of the blood (e.g. thalassaemia). Gene therapy can be somatic or germ line.
   
   
9. Cloning Humans:
   In the second half of the 20th century, as dramatic advances were taking place in genetic knowledge, as well as in the genetic technology. Some proposals suggested that persons of great intellectual or artistic achievement or of great virtue be cloned.
   
   
10. Genetically modified food: Genetically modified (GM) foods possess specific traits such as tolerance to herbicides or resistance to insects or viruses.
    
    
11. Animal cloning: Genetic engineering also includes insertion of human genes into sheep so that they secrete alpha-1 antitrypsin in their milk - a useful substance in treating some cases of lung disease.
    
    
12. Cancer treatment: Scientists have found a gene called p-53 which normally keeps cells under control and works best to suppress cancer cells.
    
    
13. Insect Killing Bacteria: Adding a gene from insect-killing bacteria to cotton so that insects, eat cotton will be poisoned!
    
    
    
    
    
    

Q.7:What is single cell protein and its uses?
Ans: Introduction:
When there were shortage in proteins and vitamins in the diet, the Germans produced yeast and a moulds (Geotrichum candidum) in some quantity for food, this led to the idea to produce edible proteins on a large scale by means of microorganisms.

Single-cell protein:
Single-Cell Protein (SCP) is a term coined at Massachusetts Institute of Technology by Prof. C. L. Wilson (1966) and represents microbial cells (primary) grown in mass culture harvested for use as protein sources in food or animal feeds.
Definition:

“The isolated protein or the total cell material from microorganisms like bacteria, yeast, filamentous fungi and algae contains carbohydrates, lipids, nucleic acid, mineral salts and vitamins, used as food or feed is called single-cell protein (SCP).”

Production OF SCP:

• Carbon substrates: major substrates used in commercial SCP production are alcohol, n-alkanes, molasses, sulphite, liquor and whey.
• SCP is a protein is a protein extracted from cultured algae, yeasts, or bacteria.
• Many types of animal feeds contain single cell protein. 60-80% dry cell weight; contains nucleic acid, fats, CHO, vitamins, and minerals rich in essential amino acids (Lys-Met).
• Microbes can be used to ferment some of the vast amount of waste materials, such as:
  Straws
  Wood and wood processing wastes
  Food cannery and food processing wastes
  Residues from alcohol production or from human and animal excreta

Uses Of SCP:
For centuries microorganisms have been widely used for the preparation of a variety of fermented foods. e.g. cheese, butter etc. Some microorganisms have long been used as food e.g. the blue-green alga, spirulina and fungi-like yeasts. Most recently, efforts have been made to produce microbial biomass using low-cost substrates. These are used as a portion of supplementary food for humans or as feed for animals.
Major source of single-cell protein:
Some of the major uses of SCP are as follows:

1. It is a rich source of protein (60 to 72%), vitamins, amino acids, minerals and crude fibres.
2. It is a popular healthy food.
3. It provides a valuable protein-rich supplement in the human diet.
4. It lowers the blood sugar level of diabetics and prevents the accumulation of cholesterol in the human body.

Side Effects:
In many countries, however, people hesitate to use SCP as a major food source because of the following:

1. The high nucleic acid content (4 to 6% in algae, 6 to 10% in yeast of SCP) can cause health problems like uric acid formation and kidney stones.
2. Toxic or carcinogenic (cancer-causing) substances absorbed from microbial growth substrate may be present.
3. The slow digestion of microbial cell in the digestive tract may cause vomiting, indigestion and allergic reaction.

Give reason?
(i) Did you ever run a race and notice that your muscles feel tired and sore afterwards. why?
Ans: This is because our muscle cells used lactic acid fermentation for energy. This causes lactic acid to build up in the muscles. It is the buildup of lactic acid that makes the muscles feel tired and sore. 

 (ii) Why small holes are formed in the sliced of bread?
Ans: The small holes are formed in the sliced of bread by bubbles of carbon dioxide gas. The gas was produced by alcoholic fermentation carried out by yeast.