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Biology 10th Class Biology

Chapter 17 Biotechnology 10th Class Biology Notes

Biotechnology 10th Class

Question 1: Define biotechnology and describe its importance. Also write a detailed note on modern biotechnology or genetic engineering? Describe the achievements of genetic engineering in medicine, agriculture and environment.

Or what is biotechnology. Write a detailed note on scope and importance of biotechnology?

 

Answer: Definition of Biotechnology: Biotechnology is defined as the use of living organisms in processes for the manufacture of useful products or for services. Or Biotechnology is the branch of biology that deals with the use of living organisms and their products for the welfare of human beings.

 

History and Origin of Biotechnology: Although the term biotechnology is new, the discipline itself is very old. It originates from that when human beings realized that they could plant their own crops and breed their own animals. Then in fermentation process conversion of fruit juices into alcohol, etc. marks the real beginning of this field. Karoly Ereky (German Karl Ereky, 1878-1952) was a Hungarian agricultural engineer who first introduced the word biotechnology in 1917. He is regarded as father of biotechnology. He was a great botanist and wrote a book on chlorophyll.

 

 

Modern Biotechnology or Genetic Engineering: The artificial synthesis, modification, removal, addition and repair of genetic material is called Modern Biotechnology Or Genetic Engineering.

Explanation: In this process cells are coded with new and advance genetic information. So it is done to alter the characteristics of organisms. The work of genetic engineering started in 1944, when it was proved that DNA carries the genetic information. Scientists isolated the enzymes for DNA synthesis and then prepared DNA outside the cells. In 1970’s they were able to cut and paste the DNA of organisms. In 1978 scientists prepared human insulin by inserting the insulin gene in bacteria. Human growth hormone was also synthesized in the bacteria. In 1990 the Human Genome Project was launched to map all the genes in human cell. The complete map of human genome was published in 2002.

 

Scope and Importance of Biotechnology:

In recent years, biotechnology is growing as a separate science. It has attracted the attention of many intellectuals from diverse fields like agriculture, medicine, microbiology and organic chemistry. The scope for biotechnology is so wide that it is difficult to recognize the limits. The following are some areas of the application of biotechnology.

 

 

Biotechnology in the Field of Medicine: Biotechnology plays important role for improvement in the health care and medicinal industries to cure various diseases. In the field of medicines biotechnology synthesize following medicines.

Synthesized insulin for the cure of diabetes mellitus.

Synthesized interferon (antiviral proteins obtained from bacteria) to cure hepatitis.

A large number of vaccines.

Production of antibodies.

Human growth hormone.

Production of various enzymes for medicinal and industrial use.

Gene therapy (Repairing of defective gene or removal or insertion of genes) means treatment through genes.

Beneficial in forensic sciences, since biotechnology enable us to identify criminals.

 

Biotechnology in the Field of Food and Agriculture: Biotechnology creates new technology to produce and increase useful varieties of agricultural products. Following are the important products.

Fermented foods like pickles, yogurt, etc.

Malted food like powdered milk, mixture of barley, wheat flour and whole milk.

Various vitamins and dairy products are produced by microorganisms.

Production of Wine and beer in beverage industry.

Biotechnology has also revolutionized research activities in the area of agriculture.Transgenic (organisms with modified genetic set-up) plants are being developed, in which desirable characteristics are present e.g. more yields and resistance against diseases, insects and herbicides. Transgenic goats, chickens, cows give more food and milk etc. Many animals like mice, goats, cows etc. have been made transgenic to get medicines through their milk, blood or urine.

 

Biotechnology and Environment: Biotechnology is also being used for dealing with environmental issues. Some of them are as follows.

Pollution control.

Development of renewable sources for energy.

Restoration of degraded lands.

Biodiversity conservation.

Bacterial enzymes are used to treat sewage water to purify.

Microbes are being developed to be used as biopesticides, biofertilizers, biosensors etc.

Transgenic microorganisms are also used for the recovery of metals, cleaning of spilled oils and for many other purposes.

 

 

 

For your information:

Biosensor: A device that senses and transmits information about a biological process as blood pressure of an individual under observation.  “OR” A device that uses biological materials to monitor the presence of various chemicals in a substance.

 

 

In Scotland, in 1997, an embryologist Ian Wilmut produced a sheep (Dolly) from the body cell of an adult sheep.

 

 

 

 

 

Question 2: What is meant by fermentation? What are the basic types of carbohydrate fermentation?

Answer: Fermentation: Fermentation is the process in which there is incomplete oxidation-reduction of glucose in the absence of oxygen.

Study or science of fermentation is called zymology.

 

 

Fermentation

Fermentation has been in the knowledge of man since centuries, but it was believed that it is purely a chemical process.

In 1857, Pasteur convinced the scientific community that all fermentations are the results of microbial activity. He showed that fermentation is always carried out by microorganisms.

 

 

Figure: Carbohydrate fermentation and its products

 

Types of fermentation: Fermentations are classified in terms of the products formed. The initial steps of each type of carbohydrate fermentation are identical to those of respiration. The process begins with glycolysis, in which the glucose, molecule is broken into two molecules of pyruvic acid. Different microorganisms proceed the further reactions in different ways. It results in the formation of various products from pyruvic acid.

The two basic types of carbohydrate fermentation are as follows.

 

  1. Alcoholic Fermentation (by yeast):The fermentation in which glucose is converted to ethyl alcohol is called Alcoholic Fermentation.

This fermentation is carried out by many types of yeast such as Saccharomyces cerevisiae. In this process, carbon dioxide is removed from pyruvic acid. The product i.e. acetaldehyde is then reduced to ethanol. The carbon dioxide produced during this fermentation causes the rise of the bread. It is also important in the production of bread, beer, wine and distilled spirits.

 

C6H12O6+ Zymase → 2 C2H5OH + 2 CO2. + Energy (ATP).

 

  1. Lactic Acid Fermentation (by bacteria):The fermentation in which glucose is converted to Lactic acid is called lactic acid Fermentation.

In this process, pyruvic acid is reduced to lactic acid. It is carried out by many bacteria e.g. Streptococcus and many Lactobacillus species. It is quite important in dairy industry where it is used for souring milk and also for production of various types of cheese.

For your information: Fears are also being expressed about the advances in biotechnology in terms of release of harmful organisms developed through recombinant DNA  technology.

 

Question 3: What is meant by fermentation in Biotechnology? OR Describe the role of fermentation in biotechnology? OR What are the applications of fermentation of biotechnology?

Answer: Fermentation in Biotechnology: In biotechnology the term fermentation means the production of any product by the mass culture of microorganisms. In beginning, the meaning of fermentation process was the use of microorganisms for the production of foods (cheese, yogurt, fermented pickles and sausages, soy sauce), beverages (beers, wines) and spirits. However, in biotechnology the term “fermentation” means the production of any product by the mass culture of microorganisms.

 

Applications of Fermentation: In fermentation process by the use of microorganisms many products are produced on commercial basis. Fermentation is used to produce following products.

Food products.

Beverage products.

Industrial products.

 

Fermented Foods: Fermentation often makes the food more nutritious, more digestible and tastier. It also tends to preserve the food, lowering the need for refrigeration. The following groups are included in the fermented foods.

Cereal products: Bread is the commonest type of fermented cereal product. Wheat dough is fermented by S. cerevisiae along with some lactic acid bacteria.

B) Dairy products:Cheese and yogurt are important fermentation products. Cheese is formed when a milk protein is coagulated. This happens when the acid produced by lactic acid bacteria reacts with milk protein. Yogurt is made from milk by different lactic acid bacteria.

C) Fruit and vegetable products:Fermentation is usually used, along with salt and acid, to preserve pickle, fruits and vegetables.

 

2) Beverage Products: Important beverage products produced by fermentation are as follows.

a) Beer:Beer is the third most widely consumed human drink prepared by fermentation of starch from different cereal grains. Preparation of beer involves following steps.

  • Preparation of fine powder of cereal grains by malting, drying and grinding.
  • Fermentation of powder is done by the yeast.
  • The glucose present in powder is converted into pyruvic acid and then into ethanol (ethyl alcohol).

b) Alcohol:Alcohol is mostly produced from molasses (Refined viscous liquid of sugar cane) by yeast and bacteria.

c) Wine: Grapes are directly fermented into wine.

d) Spirit or distilled beverages:These are ethanol containing drinks produced by fermented grains, fruits and vegetables.

 

 

3- Industrial Products

The following are the important industrial products produced through the process of fermentation.

 

ProductsMicroorganisms

used

Some uses
Formic acidAspergillusUsed in textile dyeing, leather treatment, electroplating, rubber manufacture
EthanolSaccharomycesUsed as solvent; used in the production of vinegar and beverages
GlycerolSaccharomycesUsed as solvent; used in the production of plastics, cosmetics and soaps; used in printing; used as sweetener
Acrylic acidBacillusUsed in the production of plastics

 

 

Beer is produced from cereal grains which have been malted,dried and ground into fine powder. Fermentation of the powder is done by yeast. This process breaks the glucose present in powder into pyruvic acid and then into ethanol.Grapes can be directly fermented by yeasts to wine.

 

For your information: 1) Soy yogurt is a non-dairy product produced by microorganisms from soybeans.

2) Cheese is of different types. These are due to source of milk (cow, buffalo, sheep, etc.) and type of microorganisms used for fermentation process.

 

Question 4: Write the names of most commonly used fermented products in Pakistan?

Answer: most commonly used fermented products in Pakistan are mixed pickle, cheese, bread, yogurt (Dahi), etc.

 

Question 5: What is a fermenter? What are the two types of fermentation carried out in fermenters? What are the advantages of using fermenter?

Answer:

 

Fermenter

Fermenter is a device that provides optimum environment to microorganisms to grow into a biomass, so that they can interact with a substrate, forming the product.

 

Ways how fermentation is carried out in fermenter: Fermentation is carried out in fermenters, in the following two ways.

 

Batch Fermentation: The discontinuous fermentation process divided into batches is called batch fermentation. Batch fermentation involves following steps.

 

i)The tank of fermenter is filled with the raw materials to be fermented.

ii) The temperature and pH for microbial fermentation is properly adjusted, and nutritive supplements are added.

iii) All the material is steam sterilized.

  1. iv)The pure culture of microorganisms is added to fermenter from a separate vessel.
  2. v)Fermentation proceeds and after the proper time the contents of fermenter are taken out. Fermenter is cleaned and the process is repeated. Thus, fermentation is a discontinuous process divided into batches.

 

 

 

 

Figure : A batch fermenter

 

 

 

Continuous Fermentation:

In this process, the substrate is added to fermenter continuously at a fixed rate. This maintains the microorganisms in growth phase. Fermentation products are taken out continuously.

 

 

Figure : A continuous fermenter

 

 

Advantages of using Fermenters: Following are the main advantages of using fermenter.

  1. i) It provide a control environment to microorganisms like nutrients, oxygen, growth promoters, inhibitors, pH and temperature.
  2. ii) A fermenter may hold several thousand litres of the growth medium. So, fermenters allow the production of materials in bulk quantities.

iii) Massive amounts of medicines, insulin, human growth hormone and other proteins are being produced in fermenters and this production proves much inexpensive.

  1. iv) Separation of products is easy and safe.
  2. v) Fermenter has auto control system, so environmental changes cannot harm microbe growth.

 

Question 6: What is genetic engineering? Describe the objectives and various steps of genetic engineering? What basic steps a genetic engineer adopts during the manipulation of genes?

Answer: Genetic Engineering OR Recombinant DNA technology: Genetic engineering or Recombinant DNA technology involves the artificial synthesis, modification, removal, addition and repair of the genetic material (DNA, Chromosome, Gene).

 

Genetic Engineering:

Genetic engineering or recombinant DNA technology involves the artificial synthesis, modification, removal, addition and repair of the genetic material (DNA). Genetic engineering developed in the mid-1970s when it became possible to cut DNA and to transfer particular pieces of DNA from one type of organism into another. As a result, the characteristics of the host organism could be changed. If host organism is a microorganism, such as a bacterium, the transferred DNA is multiplied many times as the microorganism multiplies. Consequently, it is possible to obtain millions of copies of a specific DNA inside a bacterial cell.

 

Objectives of Genetic Engineering

The important objectives of genetic engineering are as follows.

  • Isolation of a particular gene or part of a gene for various purposes such as gene therapy
  • Production of particular RNA and protein molecules
  • Improvement in the production of enzymes, drugs and commercially important organic chemicals
  • Production of varieties of plants having particular desirable characteristics
  • Treatment of genetic defects in higher organisms

 

Basic Steps in Genetic Engineering

All the above mentioned objectives can be obtained by some basic methodologies, such as:

 

  1. Isolation of the gene of interest

In the first step, the genetic engineer identifies the gene of interest in a donor organism. Special enzymes, called restriction endonucleases, are used to cut the identified gene from the total DNA of donor organism.

 

  1. Insertion of the gene into a vector

A vector is selected for the transfer of the isolated gene of interest to the host cell. The vector may be a plasmid (the extra-chromosomal DNA present in many bacteria) or a bacteriophage. The gene of interest is attached with the vector DNA by using endonuclease (breaking enzymes) and ligase (joining enzymes). The vector DNA and the attached gene of interest are collectively called recombinant DNA.

 

  1. Transfer of recombinant DNA into host organism

Recombinant DNA is transferred to the target host. In this way, host organism is transformed into a genetically modified organism (GMO).

 

  1. Growth of the GMO

The GMO are provided suitable culture medium for growth to give as much copies of the gene of interest as needed.

 

  1. Expression of the gene

The GMO contains the gene of interest and manufactures the desired product, which is isolated from culture medium.

 

 

Question 7: Describe the achievements or advantages of genetic engineering?

 

 

Achievements of Genetic Engineering:

Various achievements of genetic engineering are as follows.

  • Human insulin gene was transferred into bacteria. The genetically modified bacteria became able to synthesize insulin. Diabetics are now receiving this insulin.The steps of genetic engineering for the production of insulin are shown in figure.
  • In 1977 an E. coli bacterium was created that was capable of synthesizing the human growth hormone.
  • The hormone thymosin which may prove effective against brain and lung cancer has been produced by genetically modified microorganisms.
  • Beta-endorphin, a pain killer produced by the brain, has also been produced by genetic engineering techniques.
  • Genetic engineers produced a safe vaccine against the foot and mouth disease (a viral disease in cattle, goats and deer). Similarly many vaccines have been produced against human diseases such as hepatitis B.

 

Before genetic engineering, 500,000 sheep brains were required to produce 5 mg human growth hormone.

  • Interferons are anti-viral proteins produced by cells infected with viruses. In 1980, interferon was produced in the genetically modified microorganisms, for the first time.
  • The enzyme urokinase, which is used to dissolve blood clots, has been produced by genetically modified microorganisms.

 

  • Now it has become possible to modify the genes in the human egg cell. This can lead to the elimination of inherited diseases like haemophilia.
  • Genetic engineering techniques can also be used to cure blood diseases like thalassemia and sickle-cell anaemia, which result from defects in single genes.
  • Normal genes could be transferred into the bone marrow.
  • Genetic engineers have developed plants that can fix nitrogen directly from the atmosphere. Such plants need less fertilizers.

 

 

 

Figure : Production of insulin through genetic engineering

 

 

Question 8: Define the following terms?

(a) Donor.   (b) Recipient.   (c) Recombinant DNA.

 

Answer: (a) Donor Organism: The organism from which the genetic material is taken is called donor organism.

(b) Recipient Organism: The organism that receives genetic material from other is called recipient Organism.

(c) Recombinant DNA: DNA which is combination of genes from two different sources is called Recombinant DNA.

 

Question 9: What are single cell proteins? How is single cell proteins produced?  Describe their importance?

Answer: Single-Cell Protein (SCP): Single-Cell Protein (SCP) refers to the protein content extracted from pure or mixed cultures of algae, yeasts, fungi or bacteria.  “OR”   Purified dried microorganisms used as food are called single proteins. This technique was introduced by Prof. Scrimshow of Massachusetts Institute of Technology.

 

Production of SCP: For the production of single-cell proteins, the microorganisms are grown in fermenters. These microorganisms utilize a variety of substrate like agricultural wastes, industrial wastes, natural gas like methane etc. Microorganisms grow very vigorously and produce a high yield of protein. The protein content produced by microorganisms is also known as novel protein or minifood.

 

 

Need of production of SCP: We know that due to over-population, the world is facing the problem of food shortage. In future, the conventional agricultural methods might not be able to provide a sufficient supply of food (especially proteins). For a better management of food shortage problems (in humans and domestic animals), the use of microbes as the producers of single-cell proteins has been successful on experimental basis.

 

 

Significance or importance of single cell proteins: All scientists recognize the significance of the production of single-cell proteins.

1) The microorganisms grow very vigorously and produce a high yield.

2) It has been calculated that 50 kilogram of yeast produces about 250 tons of protein within 24 hours.

3) Algae grown in ponds produce 20 tons (dry weight) of protein per acre/year. This yield of protein is 10-15 times higher than soybeans and 20-50 times higher than corn.

4) single-cell proteins produced by yeasts contain high vitamin content.

5) In the production of singlecell proteins, industrial wastes are used as raw materials for microorganisms. It helps in controlling pollution.

6) The use of single-cell proteins has good prospects in future because they contain all essential amino acids.

7) Production of single-cell proteins is independent of seasonal variations. It can be produced throughout the year.

8) It has low fat contents.

 

 

Disadvantages of SCP: Due to high nucleic acid contents, it cause uric acid stones in kidney. Due to slow digestion, it may leads to vomiting, indigestion and allergy.

 

 

 

 

It is known as single cell protein because the microorganisms used as producers are unicellular or filamentous individuals.
SCP is gaining popularity day by day because it requires limited land area for production.

 

 

 

 

 

UNDERSTANDING THE CONCEPT

 

 

  1. Define biotechnology and describe its importance.

Answer: Related to question no.1.

 

 

 

 

  1. What is a fermenter? What are the two types of fermentation carried out in fermenters?

Answer: Please see answer of question no.5.

 

 

 

 

  1. Describe the achievements of genetic engineering in medicine, agriculture and environment.

Answer: Related to question no.1.

 

 

 

 

 

  1. What basic steps a genetic engineer adopts during the manipulation of genes?

Answer: Related to question no.6.

 

 

 

 

 

 

 

  1. What are single cell proteins? Describe their importance.

Answer: Please see answer of question no.9.

 

 

 

 

 

 

 

SHORT QUESTIONS

 

  1. How would you define fermentation with reference to biotechnology?

Answer: Fermentation in Biotechnology: In biotechnology the term fermentation means the production of any product by the mass culture of microorganisms. In beginning, the meaning of fermentation process was the use of microorganisms for the production of foods (cheese, yogurt, fermented pickles and sausages, soy sauce), beverages (beers, wines) and spirits. However, in biotechnology the term “fermentation” means the production of any product by the mass culture of microorganisms.

 

 

 

 

  1. Name any two industrial products made by fermentation. Also describe their uses in the industry.

Answer:

 

 

ProductsMicroorganisms

used

Some uses
Formic acidAspergillusUsed in textile dyeing, leather treatment, electroplating, rubber manufacture
EthanolSaccharomycesUsed as solvent; used in the production of vinegar and beverages
GlycerolSaccharomycesUsed as solvent; used in the production of plastics, cosmetics and soaps; used in printing; used as sweetener
Acrylic acidBacillusUsed in the production of plastics

 

 

 

  1. What are the products of the two types of carbohydrate fermentation?

Answer: Products of alcoholic fermentation are ethyl alcohol (ethanol) and carbon dioxide while that of lactic acid fermentation is lactic acid.

  1. Give an example how biotechnology is helping for better environment.

Answer: Biotechnology and Environment: Biotechnology is also being used for dealing with environmental issues. Some of them are as follows.

Pollution control.

Development of renewable sources for energy.

Restoration of degraded lands.

Biodiversity conservation.

Bacterial enzymes are used to treat sewage water to purify.

Microbes are being developed to be used as biopesticides, biofertilizers, biosensors etc.

Transgenic microorganisms are also used for the recovery of metals, cleaning of spilled oils and for many other purposes.

 

  1. In biotechnology, what is meant by Genetically Modified Organism (GMO)? How is it made?

Answer: Genetically modified organism (GMO) OR Transgenic organism: Genetically modified organism (GMO) OR Transgenic organism is any organism whose genetic material has been altered using genetic engineering techniques. These organisms are produced when a gene from one organism is purposely moved to improve another organism in the labortary.

 

THE TERMS TO KNOW:

 

Batch fermentation: The discontinuous fermentation process, divided into batches.

Biotechnology: The use of living organisms in systems or processes for the manufacture of useful products or for services for humankind.

Continuous fermentation: The fermentation in which substrate is added to the fermenter continuously, at a fixed rate.

Fermentation: The process in which there is incomplete oxidation-reduction of the organic substrate (glucose).

Fermenter: A device that provides optimum environment in which organisms can grow to produce biomass and to form the product.

Genetically modified organism: The organism in which DNA (gene) from some other organism has been transferred.

Recombinant DNA: The vector DNA and the attached gene of interest.

Restriction endonucleases: Enzymes used to cut the gene from the total DNA of the organism

Single-cell protein: The protein content extracted from pure or mixed cultures of algae, yeasts, fungi or bacteria; the micro-organisms are grown in fermenters where they produce a high yield of protein.

Transgenic organism: Organisms with modified genome (genetic make-up).

Vector: (in Biology) The DNA (plasmid) or bacteriophage etc. that transfers the isolated gene of interest to the host cell.

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