Biology X Sindh board notes

BIOLOGY CHAPTER 8

BIOTECHNOLOGY

Q.No.1: What kind of enzymes allows scientists to cut and paste pieces of DNA together to form recombinant DNA?

Ans: The following are the enzymes which allow scientists to cut and paste pieces of DNA together to form recombinant DNA:

1. RESTRICTION ENZYMES

Restriction enzymes are DNA-cutting enzymes which occur naturally. They are used by bacteria as a defense to cut up DNA from Viruses. Scientists used hundreds of these restriction enzymes to snip specific gene from DNA.

2.DNA LIGASE

DNA ligase is a DNA-joining enzyme. This enzyme is used to repair broken DNA. If two pieces of DNA have matching ends, ligase can link them to form a single, unbroken molecule of DNA. It can also be used to paste new genes into DNA.

Q.No.3: How do organisms obtain energy? How does fermentation work?

ORGANISM OBTAINS ENERGY FROM ATP

Living organisms use organic food for generation of energy. These food usually contain carbohydrates which degrade to produce CO₂, H₂O and energy. This energy is usually in the form of ATPs. An important way of making ATP without oxygen is Fermentation.

FERMENTATION:

Fermentation is an alternative term for Anaerobic respiration. 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.”

It has two major types:

1. Alcoholic (Ethanol) fermentation
2. Lactic Acid Fermentation

Q.No.4: What types of microorganisms cause fermentation to occur?

MICROORGANISMS CAUSE FERMENTATION

 Fermentation occurs in the absence of oxygen (anaerobic conditions), and in the presence of beneficial microorganisms. Some beneficial microorganisms for fermentation are yeasts, molds, and bacteria that obtain their energy through fermentation.

Similarly the lactic acid fermentation is carried out by the bacteria Streptococcus and Lactobacillus. They help in souring milk for yogurt and is also helpful in production of various types of cheese. The alcoholic fermentation uses Saccharomyces cerevisiae, a type of yeast to make bread and wine etc.

Q.No.5: What food and nonfood products are created by fermentation?

Ans: Food Products Created By 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.No.6: What are some advantages and disadvantages of fermentation?

ADVANTAGES:

1. Yeast is used to prepare bread from wheat.
2. Milk is converted to curd (yogurt) by bacteria.
3. Preparation of cheese and other dairy products.
4. Production of lactic acid, propionic acid, and butanol.
5. Flavour of pickles is due to lactic and acetic acid.
6. It improves the immune system.

DISADVANTAGES:

1. It is linked with the development of gastric cancer.
2. Store-bought items lose beneficial bacteria.
3. Fermentation is a slow and inefficient process.
4. It is vulnerable to contamination.

Q.No.7: What factors can affect the fermentation process?

FACTORS EFFECT FERMENTATION PROCESS

There are several factors which affect the process and progression of both alcoholic and lactic acid fermentation. These include:

• Fermentation time
• pH
• Presence of air
• Temperature
• Salt
• Water
• Concentration of sugar
• Contaminating organisms

Q.No.8: Define biotechnology.

BIOTECHNOLOGY

“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 is the use of living organisms, cells or cellular components for the production of compounds or precise genetic improvement of living things for the benefit of man.”

Q.No.10: What is your justification in considering biotechnology an old technology?

BIOTECHNOLOGY IS CONSIDERED AN OLD TECHNOLOGY

Farmers Were Earliest Biotechnologist:

The earliest biotechnologists were farmers who developed, improved species of plants and animals using cross-pollination or cross-breeding techniques. The use of these techniques to manufacture products intended to improve the quality of human life.

Food Production in Early time:

Food has been an inevitable need since the existence of man as well as for continuous existence of human beings. The term “Biotechnology” was used before the twentieth century for traditional activities such as making dairy products like cheese and curd, as well as bread, wine, beer, etc.

Q.No.12: What are different types of fermentation?

FERMENTATION

“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

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.

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.

Q.No.13: What is lactic acid bacillus? Explain its role in fermentation of curd?

 LACTIC ACID BACILLUS:

Lactic acid bacillus are inactivated bacteria that are good for the gut. They prevent the growth of the other pathogenic bacteria that cause diarrhea or other bacterial infections. Thus, it helps in treating bacterial infections.

ROLE OF LACTIC ACID BACILLUS IN FERMENTATION OF CURD:

Lactic acid bacillus is very helpful in formation of curd. When it is added to milk the bacterium uses enzymes to produce energy (ATP) from lactose. The lactic acid curdles the milk that then separates to form curds, which are used to produce cheese and whey.

Q.No.15: Name four recombinant DNA products available on the market? Ans: Recombinant DNA Products:

Biochemical products of recombinant DNA technology in medicine and research include:

• Human recombinant insulin
• Growth hormone
• Blood clotting factors
• Hepatitis B vaccine.