KPK Class 10 Chemistry Notes Chapter #13 (Biochemistry)

High School KPK Class 10 Chemistry Notes Chapter #13 (Biochemistry) for all educational Pakistan boards.

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Short Questions KPK Class 10 Chemistry Notes Chapter #13 (Biochemistry)

Q.1) Differentiate between glucose and fructose? 

Answer: 
Difference between glucose and fructose:

Differentiate between glucose and fructose

Q.2) Write down two uses of lipids. 

Answer: 
Uses of lipids:
i. Lipids perform many important functions in the body. Their most important function is the long-term storage of energy. One gram of fat contains approximately twice more energy than a gram of carbohydrate or protein. 
ii. Butter, oil, and ghee are used for cooking and frying of food items, for preparing bakery products and making the food more palatable. 

Chemistry 10th Class Chapter 13 Notes

Q.3) How would you differentiate between simple and complex lipids. 

Answer: 
Difference between simple and complex lipids

Simple lipidsComplex lipids
These lipids are also known as triglycerides. They produce fatty acids and alcohols upon hydrolysisThose lipids which produce fatty acids, alcohols and some other substances upon hydrolysis are known as complex lipids
Do not carry other substances like complex lipids. Carry groups like phosphate, nitrogenous bases, proteins, carbohydrates, etc.
Examples: Fats, Oils, and Waxes.Examples: Phospholipids, Glycolipids, Sulpholipids, etc.

Q.4) What is meant by denaturing of protein? 

Answer: 
Denaturing of protein means precipitation or coagulation of protein. It can be carried out by heating or changing pH. When the temperature or pH is changed, the internal interactions between amino acids can be altered, which in turn may alter the shape of the protein, so that it becomes dysfunctional. And the protein is considered denatured. A simple common method for denaturing of protein is boiling of an egg. White viscous fluid (albumen) present in an egg is protein. When the egg is boiled for a few minutes, albumen coagulates i.e. solidifies.

Q.5) How would you classify vitamins? 

Answer: 
Vitamins: Vitamins are specific organic compounds that are vital nutrients an organism requires in limited amounts. There are two types of vitamins.
1. Fat-soluble
2. Water-soluble.
1. Fat-soluble vitamins: Vitamins which dissolve in fats are called fat-soluble vitamins. These are vitamins A, Vitamin D, Vitamin E, Vitamin K.
2. Water-soluble vitamins: Vitamins which dissolve in water are called water soluble vitamins. These vitamins are vitamin B-Complex (includes eight vitamins) and vitamin C (ascorbic acid).

Q.6) Vitamins are vital for us, why? 

Answer: 
Each vitamin plays an important role in the healthy development and growth of our body. They play an important role in bodily functions such as metabolism, immunity, and digestion. They arenecessary for the formation of blood, improvement of the immune system and protection against different diseases.bVitamin A is important for vision, it also keeps the cornea moist. Vitamin E has been considered responsible for youth preserving and a defender against the carcinogenic  (cancer-causing) effects of certain chemicals.

Read more: Biology class 10 notes All chapters 10 to chapters 18

Q.7) Write down products of sucrose hydrolysis.

Answer: 
Sucrose is a disaccharide and on hydrolysis, it is converted into two monosaccharides glucose and fructose. 

Q.8) Draw the general formula of amino acid. Identify the different parts of the functional groups present in it. 

Answer: 
The general formula of amino acid is as follows:

Draw the general formula of amino acid. Identify the different parts of the functional groups present in it

Q.9) Briefly describe the sources and deficiency symptoms of vitamin A. 

Answer: 
Sources and Deficiency Symptoms of Vitamin A:
Sources:
 Milk, butter, fish oils, eggs, fresh green vegetables, and fruits.
Deficiency Symptoms:
 Night blindness, dry skin, burning/irritation of eyes.

Q.10) Identify the different sources of proteins? Also, list the four uses of proteins. 

Answer: 
Each protein has its source and performs a specific function.
Sources of protein:
Animal: Animal sources of proteins are fish, meat, eggs and milk, cheese, etc.
Plant: Pulses, beans, etc are plant sources of proteins and are used as a food source.
Uses of proteins:
i. As Oxygen carrier: Proteins (haemoglobin) perform the functions of oxygen transportation in the blood (act as an oxygen carrier). Proteins are used as food by human beings, as it is essential for the formation of protoplasm and components of cells.
ii. Body structures: Like skin, nail, hair, hoofs, horns and feather are composed of proteins.
iii. Growth: Proteins are essential for the physical and mental growth especially in children.
iv. Enzymatic action: Enzymes are proteins, which are produced by the cells of living organisms. Enzymes catalyze the biochemical reactions going on in our bodies. 


Long Questions KPK Class 10 Chemistry Notes Chapter #13 (Biochemistry)

Q.1) What functions do carbohydrates perform in living organisms? 

Answer: 
The following are the functions of the carbohydrates they perform in living organisms:
1. Carbohydrates are used by our body as a rich source of energy.
2. Sugar is used as a common sweetener for food.
3. Carbohydrates serve as a source of food.
4. Carbohydrates serve as a structural material for plants.
5. Cellulose helps in lowering cholesterol and regulates blood pressure.
6. Glucose is stored in animal muscles and liver cells in the form of glycogen. It serves as a long-term energy reservoir in the body, converted back into glucose when need. Plants store excess energy in the form of starch.
7. Constipation and diarrhea are mainly controlled by the use of fibers which are carbohydrates.

Q.2) (a) Distinguish between monosaccharides, disaccharides, and polysaccharides and also give examples of each one. 

Answer: 

MonosaccharidesDisaccharidesPolysaccharides
Monosaccharides are the simplest carbohydrates which cannot be hydrolyzed into simple units.Disaccharides are the sugars which on hydrolysis give two molecules of monosaccharides or simple sugars.  Polysaccharides are complex carbohydrates and give many molecules of monosaccharides on hydrolysis
The general formula of simple monosaccharide is Cn­H2nOn, where ‘n’ is 3 to 9 carbon atoms.They are called disaccharide because they consist of only two monosaccharide units.They have high molecular mass and consist of 100 or more monosaccharides units joined together through glycosidic linkages.
Most they have a sweet taste (fructose is 73% sweeter than sucrose).Disaccharides are usually sweet in taste. Polysaccharides are tasteless and are called ‘non-sugars’.
They are usually colorless crystalline solids at room temperature. They are white crystalline solids.They are amorphous solids. 
They are completely soluble in water. The presence of large number of OH groups make them much more water-soluble than most molecules of similar molecular mass.Disaccharides are easily soluble in water. Polysaccharides are insoluble in water.
Examples: Glucose (C6H12O6), Fructose (C6H12O6), and Galactose.Example: Sucrose, when hydrolyzed it gives one molecule of glucose (C6H12O6)  and one molecule of fructose (C6H12O6).Examples: Starch, glycogen and cellulose (main component of the cell wall in plants).
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Q.2) (b) How are carbohydrates important to living organisms? 

Answer: 
The following are the functions of the carbohydrates they perform in living organisms:
1. Carbohydrates are used by our body as a rich source of energy.
2. Sugar is used as a common sweetener for food.
3. Carbohydrates serve as a source of food.
4. Carbohydrates serve as a structural material for plants.
5. Cellulose helps in lowering cholesterol and regulates blood pressure.
6. Glucose is stored in animal muscles and liver cells in the form of glycogen. It serves as a long-term energy reservoir in the body, converted back into glucose when need. Plants store excess energy in the form of starch.
7. Cellulose is used in the form of wood for housing, furniture, and heating purposes.
8. Cellulose is used to make paper and wood pulp (paper industry).
9. Cellulose is used in the cotton industry for making clothes (textile industry).
10. Constipation and diarrhea are mainly controlled by the use of fibers which are carbohydrates.

Chemistry Online Course / Notes Class 10th Ch#13

Read moe: KPK G10 Chemistry Notes Chapter-10 (Acids, Bases, Salts)

Q.3) (a) How are proteins important to living organisms? 

Answer: 
Importance of proteins:
i. As Oxygen carrier:
 Proteins (haemoglobin) perform the functions of oxygen transportation in the blood (act as an oxygen carrier). Proteins are used as food by human beings, as it is essential for the formation of protoplasm and components of cells.
ii. Body structures:
 Like skin, nail, hair, hoofs, horns and feather are composed of proteins.
iii. Growth:
 Proteins are essential for the physical and mental growth especially in children.
iv. Enzymatic action:
 Enzymes are proteins, which are produced by the cells of living organisms. Enzymes catalyze the biochemical reactions going on in our bodies.
v. As Body Regulators: Hormones and enzymes are the chemical regulators of the body.
vi. Commercial Uses of Enzymes: Enzymes help in improving the quality of products such as textile, detergents, foods and beverages. Vinegar and cheese are also produced due to the utilization of enzymes in bacteria and yeast.
vii. Body Defense System: The antibodies that help us to fight against diseases are large protein molecules.
viii. Other Uses: A protein called gelatin is used as bakery items. Animal Hides are also made up of proteins. Which are used to make leather and leather is used for making shoes, jackets, sports items etc. 

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Q.3) (b) Describe the nature of bonding in protein? 

Answer: 
In protein molecules, three types of bonding may occur i.e.
i. Peptide bonding
ii. Hydrogen bonding
iii. Disulphide bridges.
Each amino acid has a chain designated a ‘R’ (alkyl group). The various amino acids differ in their side chains or alkyl groups (R).
Disulphide bridges are found only in sulphur-containing protein molecules. The presence of hydrogen bonding and disulphide bridges in protein molecules cause it to fold to produce secondary, tertiary and quaternary structures.

Q.4)  (a) Define the term lipid. 

Answer: 
The term lipid is derived from Greek word “lipose” which means “fats”. Lipids are defined as biological molecules obtained from plant and animal tissues. They are not soluble in water, but are soluble in non-polar organic solvents, such as alcohol, chloroform, ether etc.

Q.4) (b) Distinguish between fats and oils. 

Answer: 

FatsOils
Those triglycerides in which long-chain saturated fatty acid components predominate, tend to be solid or semisolid at room temperature e.g. palmitic acid. These are glycerol esters which contain higher proportion of unsaturated fatty acid components which make them liquids at room temperature e.g. oleic acid. 
Fats are mainly present in animals. Oils are mainly present in plants and in fish. 
Distinguish between fats and oils

Q.4) (c) List four foods you eat that contain lipids. 

Answer: 
Milk, Fish, Cheese, Meat and Butter are rich sources of lipids.

Q.4) (d) How are lipids important to your body? 

Answer: 
Importance of Lipids in Human Body:
1. Lipids perform many important functions in the body. Their most important function is the long-term storage of energy. One gram of fat contains approximately twice more energy than a gram of carbohydrate or protein.
2. The fatty tissues in our body are made from lipids. A protective layer of fat around our heart, kidneys etc. reduces the impact of any external jerk or shock.
3. Lipids are and integral part of cell-protoplasm and plasma membrane.
4. Lipids such as cholesterol etc acts as hormones to regulate body functions.

Read more: KPK Class 10 Chemistry Notes Chapter 11 (Organic Chemistry)

Q.5) (a) How would you justify DNA as genetic code of life?  

Answer: 
DNA has the ability to reproduce, store and transmit genetic information from generation to generation. The genetic information for the cell are contained in the form of specific codes in DNA molecules. DNA also instructs how to synthesize a particular protein from amino acids. These instructions are known as genetic code. 

Q.5) (b) Distinguish between DNA and RNA. 

Answer: 

DNARNA
DNA stands for deoxyribonucleic acid and mostly found in nucleus and nucleoidRNA stands for ribonucleic acid and mostly found in cytoplasm
The sugar is deoxyribose and have the nitrogenous base ThymineIn RNA sugar is ribose with nitrogenous base Uracil instead of thymine.
A pairs with T and C pairs with GA pairs with U and C pairs with G
DNA is double-stranded and it exhibits a double-helix structure. RNA is single strand, sometimes forms secondary and tertiary structures.
Carries the genetic information necessary for the development, functioning, and reproductionInvolved in protein synthesis, sometimes regulates gene expression.

Q.5) (c) Explain the functions of DNA. 

Answer: 
Functions of DNA:
1. DNA has the ability to reproduce, store and transmit genetic information from generation to generation. The genetic information for the cell are contained in the form of specific codes in DNA molecules.
2. DNA also instructs how to synthesize a particular protein from amino acids. These instructions are known as genetic code. Protein then performs various functions in cell according to the directions given by the codes in DNA.
3. Mutation is a sudden chemical change in a DNA (Deoxyribonucleic acid) molecule that could lead to the synthesis of proteins with an altered amino acid sequence.

Q.6) (a) Define the term Vitamin and classify it. 

Answer:
Vitamins are specific organic compounds that are vital nutrients an organism requires in limited amounts but can not be synthesized by an organism. They are very essential for the maintenance of normal metabolism. The name vitamin was originally vitamine, because the first one that was found was an amine, hence the name vital amine or vitamine. Subsequent studies of other such substances showed that they were not all amine. So, the “e” was dropped.
There are two types of vitamins.
                    1. Fat-soluble                                  2. Water-soluble.
1. Fat-soluble vitamins: Vitamins which dissolve in fats are called fat-soluble vitamins. These are vitamins A, Vitamin D, Vitamin E, Vitamin K.
2. Water-soluble vitamins: Vitamins which dissolve in water are called water soluble vitamins. These vitamins are vitamin B-Complex (includes eight vitamins) and vitamin C (ascorbic acid).

Q.6) (b) Explain the important sources of vitamins. 

Answer: 
Important Sources of Vitamins: 

VitaminSources
AMilk, butter, fish oils, eggs, fresh green vegetables and fruits. 
B (complex of eight vitamins) B1, B2, B3, B5, B6. Biotin, Folic acid and B12   Bread, rice, yeast, liver, milk, meat, fish, eggs, soybean oil, fresh green vegetables. 
C (Ascorbic acid)Citrus fruits (orange, lemon) etc, tomatoes, fresh green vegetables.
EBread, rice, eggs, liver, butter, fresh green vegetables, corn and soybean oil.
KFresh green vegetables, liver, egg, yolk, meat, cheese.

Read more: KPK Class 10 Chemistry Notes Chapter #12 (Hydrocarbons)

Q.6) (c) Write down the names of five vitamins and their importance. 

Answer: 
Each vitamin plays an important role in the healthy development and growth of our body. They play an important role in bodily functions such as metabolism, immunity, and digestion.
(i) Vitamin A is important for vision, it also keeps the cornea moist. Deficiency symptoms are night blindness, dry skin, burning/irritation of eyes. 
(ii) Vitamin B helps to regulate nerve impulse transmissions. Play a role in energy production in cells, nerves and skin. Vitamin B deficiency causes skin diseases, tongue/lip inflammation, anaemia, and beriberi.
(iii) Vitamin C is necessary for the formation of blood, improvement of the immune system and protection against illness, including the common cold. Deficiency of vitamin C causes Scurvy (bleeding from gums), pain in joints.
(iv) Vitamin D regulates blood calcium, necessary for proper bones and tooth growth. Deficiency causes Rickets, osteomalacia.
(v) Vitamin E acts as an antioxidant and has been considered responsible for youth preserving and a defender against the carcinogenic (cancer-causing) effects of certain chemicals. Its deficiency causes haemolysis of red blood cells (Anaemia), sterility.

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