CLASS 10th CHEMISTRY NOTES CHAPTER 13 BIOCHEMISTRY

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CLASS 10th CHEMISTRY NOTES CHAPTER 13 BIOCHEMISTRY

CLASS 10th CHEMISTRY NOTES CHAPTER 13 BIOCHEMISTRY. Biochemistry or biological chemistry is the study of chemical processes within and related to living organisms. A sub discipline of chemistry and biology, biochemistry can be divided into three fields: structural biology, entomology, and metabolism. During the last decades of the 20th century, biochemistry has been successful in explaining living processes through these three disciplines. CLASS 10th CHEMISTRY NOTES CHAPTER 13 BIOCHEMISTRY.

CLASS 10th CHEMISTRY NOTES CHAPTER 13 BIOCHEMISTRY
CLASS 10th CHEMISTRY NOTES CHAPTER 13 BIOCHEMISTRY

CLASS 10th CHEMISTRY NOTES CHAPTER 13 BIOCHEMISTRY

CLASS 10th CHEMISTRY NOTES CHAPTER 13 BIOCHEMISTRY. Almost all areas of the life sciences are being discovered and developed through biochemical research and methodology. Biochemistry focuses on understanding the chemical basis that allows biological molecules to give rise to the processes that occur within living cells and between cells, in turn related to a large extent with the understanding of the tissues and organs, as well as the structure and function of the body. Biochemistry is closely related to molecular biology, which is the study of the molecular mechanisms of biological phenomena.CLASS 10th CHEMISTRY NOTES CHAPTER 13 BIOCHEMISTRY.

CLASS 10th CHEMISTRY NOTES CHAPTER 13 BIOCHEMISTRY
CLASS 10th CHEMISTRY NOTES CHAPTER 13 BIOCHEMISTRY

CLASS 10th CHEMISTRY NOTES CHAPTER 13 BIOCHEMISTRY

CLASS 10th CHEMISTRY NOTES CHAPTER 13 BIOCHEMISTRY. Much of biochemistry deals with the structures, functions, and interactions of biological macro molecules, such as proteins, nucleic acids, carbohydrates, and lipids. They provide the structure of cells and perform many of the functions associated with life. Cell chemistry also depends on the reactions of small molecules and ions. These can be inorganic or organic. CLASS 10th CHEMISTRY NOTES CHAPTER 13 BIOCHEMISTRY.

CLASS 10th CHEMISTRY NOTES CHAPTER 13 BIOCHEMISTRY

CLASS 10th CHEMISTRY NOTES CHAPTER 13 BIOCHEMISTRY. The mechanisms that cells use to harness energy from their environment through chemical reactions are known as metabolism. The discoveries of biochemistry are applied mainly in medicine, nutrition and agriculture. In medicine, biochemists research the causes and cures of disease. Nutrition studies how to maintain health and well-being and also the effects of nutritional deficiencies. In agriculture, biochemists investigate soil and fertilizers. Improving crop cultivation, crop storage, and pest control are also objectives.CLASS 10th CHEMISTRY NOTES CHAPTER 13 BIOCHEMISTRY.

CLASS 10th CHEMISTRY NOTES CHAPTER 13 BIOCHEMISTRY

Chapter No.13

word image 39

Q.1 Define Biochemistry.

Ans. Biochemistry:

“The branch of chemistry which deals with the study of synthesis, decomposition of substances and their reactions in living organisms such as plants and animals is called biochemistry”. OR “The branch of chemistry that deals with the chemical compounds and processes occurring in organism.”

Q.2 What are biological molecules?

Ans. Biological molecules:

“The organic compounds present in living organisms are called biological molecules.” Biological molecules include carbohydrates, proteins, lipids or fats, enz mess, vitamins and nucleic acids.

3. What are carbohydrates? Explain the classification of carbohydrates along with the uses of carbohydrates.

Ans. Carbohydrates:

Origin of name:

Since most of carbohydrates have the general formula Cn (H20), (n can have a value of 3 or more than 3) therefore, they are called carbohydrates meaning hydrates of carbon. However, now days many carbohydrates have been discovered which do not have the general formula of Cn (H20), and cannot be called hydrates of carbon however the name carbohydrate is still retained. E.g. Fructose (C6H1205).

Definition:

“Polyhydroxy ketones or Polyhydroxy aldehydes are called carbohydrates.” OR

“Polyhydroxy derivatives of aldehydes and ketones are called carbohydrates.

Polyhydroxy means having many hydroxyl groups.

Common name:

Carbohydrates are commonly known as sugars. They are also referred as saccharides (Latin word Sacharum meaning sugar)

Composition:

Carbohydrates are poly functional (alcohol + aldehydes or ketones) organic compounds which mainly consist of carbon, hydrogen and oxygen some time along with nitrogen (chitin) or Sulphur (keratin sulphates). Classification of carbohydrates:

Carbohydrates are classified into the following three groups:

1. Monosaccharide’s 2. Oligosaccharides 3. Polysaccharides their detail is given below;

1. Monosaccharide’s:

Definition:

“The simplest carbohydrates which cannot be further hydrolyzed into smaller units are called monosaccharaides.”

General formula:

They have the general formula of Cn (H20),, where n=3,4.5 and so on. Composition:

Monosaccharide is either aldoses having aldehydes functional group (for example glucose) or ketoses having kenotic functional group for example fructose.

These may be trioses (C3H603), tortoises (C4HSO4),

Pentoses (C5F1, 005) and hexoses (C6H1206).

General properties of monosaccharaides:

Some general properties of monosaccharaides are:

i. Solubility:

They are soluble in water.

ii. Physical state:

They are crystalline solids.

iii. Taste:

They have sweet taste.

iv. Colour:

They are colorless.

v. Hydrolysis:

They cannot be hydrolyzed further.

Examples:

The most important monosaccharaides are glucose and fructose. They are hexoses having molecular formula of C61-11206. Glucose is pentahydroxy aldehyde while fructose is pentahydroxy ketone. Their structures are given below:

HO – CHs HO – CH:

OH OH 1; l/ OH

\C C C HO-CK

H OH

Hi CH2OH OH

C C Fructose

Galactose

H OH

OH

C C

I 1

H 0H

Glucose

Aldoses Ketoses

HEXOSE SUGARS (C61-11z0a)

H-1?-0H

2C=0

HO-3C—H

H—C—OH

H— 5C—OH

CI

OH

H

Fructose

H \ \

  1. H 0

H —C—OH H —C—OH

21 i

HO—F—H HO—C—H

I 1

H—O—OH HO—C—H

41 H—C—OH H—C—OH

51 1

HC—OH H—C—OH

H H

Glucose Galactose

. Oligosaccharides:

“Carbohydrates containing two to nine monosaccharide units are called oligosaccharides.” OR

“The carbohydrates which yield two to nine monosaccharide units on hydrolysis in the presence of an acid or enzyme are called oligosaccharides.”

Formation:

They are formed when two to nine monosaccharide molecules combine with each other by the loss of water molecules. These molecules are bonded with each other through glycoside linkage.

Types:

Oligosaccharides have many types but two of them are described below: a.

Disaccharides:

“Those oligosaccharides which consist of two monosaccharide units are called disaccharides.”

Examples:

 

monosaccharide Glucose + Glucose Glucose + Galactose Glucose + Fructose

Disaccharides

Maltose

Lactose

Sucrose

Disaccharides:

“Those oligosaccharides which consist of three monosaccharide units are called trisaccharides.”

Examples:

Raffinose, kestose and malt triose (C181-132016) etc.

General properties of oligosaccharides:

Some general properties of oligosaccharides are:

  1. They are soluble in water.
  2. Physical state:

They are crystalline solids.

iii. Taste:

They have sweet taste.

iv. Colour:

They are colorless.

v. Hydrolysis:

They give two to nine monosaccharide units on hydrolysis. 3. Polysaccharides:

“The biopolymers of monosaccharaides which consist of 100 or more monosaccharide units joined together through glycoside linkage are called polysaccharides.”

Polysaccharides have high molecular weight, they are macromolecules and they hydrolyzed to give many molecules of monosaccharaides e.g.

(C61-11005) n + nH2O H > n (C61-1,200

Starch Glucose

General properties of polysaccharides:

i. Physical state:

They are amorphous solids.

ii. Taste:

They are tasteless and are called non-sugars.

iii. Solubility:

They are insoluble in water.

iv. Hydrolysis:

They give many molecules of monosaccharaides on hydrolysis. Examples:

Cellulose, starch, dextrin and glycogen etc. are the examples of polysaccharides.

Function:

Polysaccharides perform two main functions in animals and plants

i. They are used as energy storage of cell.

ii. They are used as structural unit of cell.

Carbohydrates

1 I -I

Monos ccharides Oligosaccharides Polysaccharides

1 1

Disaccv harides Trisaccharides Structural Storage

(e.g., SucroseMaltose) Polysaccharides Polysaccharides

(e.g., Cellulose) (e.g., Starch, Glycogen)

+ * —– *

Trioses Tetroses Pento i-ses Hexo+ ses Heptodes

(e.g., Ribose) (e.g., Glucose Fructose)

Classification of carbohydrates

Describe the sources and uses of carbohydrates.

Ans. Sources of carbohydrates:

The sources of different types of carbohydrates are given below:

i. Sources of monosaccharide:

The sources of monosaccharaides are given below:

A. fruits b. vegetable c. cereals d. honey etc.

ii. Sources of Oligosaccharides:

Disaccharides like sucrose, lactose and maltose are the examples of oligosaccharides. Their sources are described as under:

a. Sources of Sucrose:

The sources of sucrose are sugar cane, sugar beet and fruits like mango, apple, pineapple etc.

b. Sources of Lactose:

The sources of lactose are milk and dairy products.

Sources of Maltose:

The sources of maltose are cereals like barley, corn etc. Similarly, Raffinose is trisaccharides composed of Galactose, glucose and fructose. It can be found in beans, cabbage, broccoli and asparagus etc.

iii. Sources of Polysaccharides:

Cellulose and starch are the examples of polysaccharides. Their sources are given below:

a. Sources of Cellulose:

Plants are the main source of cellulose. For example cotton is pure cellulose obtained from cotton plant. Cellulose is also the major constituent of paper. Paperboard etc.

b. Sources of Starch:

It is found in cereal crops like barley, wheat, maize, rice, potatoes etc. Uses of carbohydrates:

Carbohydrates play a vital role in our daily life. Some of their used are given below;

i. Textile industry:

Carbohydrates like cellulose in the form of cotton are used in the manufacture of cloth.

ii. Paper industry:

Cellulose is used in making of paper.

iii. Medical uses:

Constipation and diarrhea are controlled by the use of fibers which are carbohydrates. Similarly, cellulose helps to lower cholesterol level and regulates blood pressure.-

Iv. As a source of energy:

Carbohydrates also act as a chief source of energy in living organisms. For example, glucose in the form of glycogen is stored in animal liver and muscles cells. It is converted back into glucose when needed. Plants store excess food in the form of starch.

V. As a structural material:

They act as a structural material for plants.

Vi. In furniture:

Cellulose in form of wood is used in making furniture.

Vii. For food sweetness:

Sugar is a common carbohydrate used a food sweetener.

As a source of food:

Carbohydrates serve as a source of food.

Glycoside linkage or bond:

The bond between two rings in an oligosaccharide or polysaccharide is known as glycoside linkage or bond.” Society, .1 Science

Dextrose drips are injected to dehydrated and weak patients in clinics and hospitals. In this process oxidation of dextrose takes place in the blood which is converted into carbon dioxide, water with release of energy. That is why, it is. Not only has an instant source of energy but compensated loss of water by dehydration. Do you know?

All the carbohydrates are of plant origin except lactose which is f animal origin. Sugars (mono and oligosaccharides) are soluble in water at normal conditions but polysaccharides e.g. starch are not soluble in water at normal conditions. Their solubility increase with heating but they do not give true solutions.

Describe proteins, the nature of bonding in proteins and their uses.

Ans. 1. Proteins Origin of word protein:

Protein is derived from Greek word “Proteios” which means “of prime importance”. Because they are essential for the growth and maintenance of life. Proteins are biopolymers of amino acids.

Definition:

“The complex nitrogenous compounds essential for the growth and maintenance of all living organisms are called proteins.” (OR)

“The complex organic nitrogenous compounds that have globular or fibrous structure composed of linked amino acids are called proteins.” Explanation:

Composition of proteins:

Proteins consist of elements like nitrogen, carbon, hydrogen, oxygen and sulphur. Amino acids are the building blocks of proteins. Proteins are the major components of cells. About 50-55% of dry weight of cell is made of proteins.

In a protein polymer, the amino acids are linked together through “Peptide linkage”

ii. Formation of proteins:

Proteins are polyamides formed by the condensation of alpha-amino acids with a molecular weight greater than 10000.

iii. Collective name of protein, carbohydrate and lipid:

Proteins, carbohydrates and lipids are important food- stuffs collectively called triumvirates. (Triumvirates is Latin word meaning group of three things or persons)

Examples:

Some examples of proteins are given below;

i. Hemoglobin ii. Globulin iii. Keratin IV. Albumin etc.

21Clature of bonding in proteins:

In proteins three types of bonding may occur:

i. Peptide bonding

ii. Hydrogen bonding

Iii.Disulphide bridges

, As proteins are formed from the joining of amino acid molecules therefore first we discuss bonding in amino acids:

2.1 Bonding in amino acids:

Amino acids consist of carbon, hydrogen, oxygen and nitrogen bonded through covalent bonds. Some amino acids also contain sulphur.

The general structure of amino acids consists of carboxylic group (COON) and amino group (NH2) attached to the same carbon atom (alpha carbon). Each amino acid also has an alkyl group R called the side chain. The various alpha amino acids differ in their side chain(R). The R may be simple e.g. in glycine R is a H-atom ‘while it may be complex e.g. in tryptophan R includes two ring structures. Twenty different amino acids are commonly found in proteins.

H –

1(Alpha carbon)

H2N C – COO H

(Amino group) (Carboxylic group)

R (side chain)

General structure of amino acid

2.2 Protein formation from amino acids:

Protein molecules are formed from 20 different types of amino acids when they linked together with the elimination of water molecules. This process is called condensation. As a result, a linear protein polymer is formed.

In these 20 amino acids 10 are prepared by our body which is non-essential while the rest are essential amino acids which are obtained through the food we eat.

El 0 1-1 0

H.

N—C—C N—C—C

H/H \ OH}-1/ H \ OH

(Amino Acid)

G’0 H 0 Fl 0

H, I H

H2o

“‘ LT-H SOH

Peptide Bond

2.3 Peptide linkage/bonding:

The bonding between carbonyl group (-C-) and NH group are called peptide linkage or bonding. Amino acids main skeleton are linked through peptide bonding to form proteins.

0 R2 H

NH2 II I I

— CH C —-„N ___. — CH —, c. „– N –….„_Af____,- COOH

IR

I I I\H II i

,

0 /74

\ / D “3

Peptide Bonds

Hydrogen bonding:

The hydrogen bonding establishes between 0 of carbonyl group (-C-) and H of -NH- group in proteins.

– 0=7 Hydrogen bonding

\N„

21-14″”

-R -C:

H-V

Protein molecule

2.4 Disulphide bird seconding:

The Disulphide bonds or bridges occur only in sulphur containing proteins. In these -SH- group are bonded to form Disulphide linkage, -H-S-S-H-.

Due to Disulphide bonding and hydrogen bonding the protein molecules get folded and refolded to give secondary, tertiary and quaternary structures.

H

H2N — C — COOH

1-12

S A Disulphide bond

H2

H2N — C

COOH

H

Protein molecules may be globular as in hemoglobin and antibodies or they may be fibrous e.g. keratin in skin and nails. \‘s/function/Importance of proteins: The following are the uses of proteins;

i. Body structure:

They support body structure e.g. skin, nail, feather, hoofs horns are composed of proteins

Ii. As oxygen carrier:

Hemoglobin is a protein which carries oxygen to all cells of body.

iii. As body regulators:

Proteins like hormones and enzymes are chemical regulators in the body.

iv. Commercial uses of enzymes (proteins):

Enzymes are proteins with catalytic function. They change starch into sugar. They also help in improving the quality of products such as textile detergents foods and beverages. Vinegar and cheese are also produced due to the use of enzymes in yeast and bacteria.

v. Body defense system:

Proteins like antibodies increase the immune power of the body.

vi. Growth:

Proteins are essential for the physical and mental growth especially in children.

vii. in bakery items:

Protein like gelatin is used in bakery items.

Viii. In making leather:

Animal hides are also made up of proteins which are used to make leather.

ix. Enzymatic action:

Enzymes are proteins which catalyze biochemical reactions, occurring in living things.

C, \A

Q. Describe the sources of proteins.

Ans. Sources of proteins:

Plants and animals are the main sources of proteins. They are discussed below:

Animal sources:

Eggs, milk, cheese, meat, fish etc. are the animal sources of proteins.

Plant sources:

Pulses, beans are the plant sources of proteins.

Activity 1:

Take an egg

1) Boil it in water and see what happens.

2) Compare and record the observation about the denaturing of proteins.

Ans: When an egg is boiled in water, the structure of its protein molecules (albumin) is disturbed and it is denatured.

Denaturation:

It is a process in which proteins lose their secondary structure (shape of protein molecules caused by hydrogen bonding) and tertiary structure(folding and bending of proteins caused by R groups) by heat or some chemical substances.

Explain lipids with classification, sources and uses?

Ans. Lipids:

Origin of word lipid:

The term lipid is derived from Greek word “lipase” which means fats.

Definition:

“Naturally occurring organic compounds of plant and animal origin which are insoluble in water and soluble in organic solvents like acetone, ether etc are called lipids.”

Composition:

Lipids are generally composed of carbon, hydrogen and oxygen. Generally, lipids are long chain fatty acids of esters and alcohols. These esters are made up of three fatty acids called triglycerides. Thus the primary building block of lipids is fatty acids and alcohols.

H —C—OH H —C-0— C —R

H —C —OH + 3 [HO—C—R►H—C-0— C—R

H—C—OH H—C-0— C— R

Glycerol Fatty acids Fat molecules

Examples:

Sever31-yr

They are given below:

a. Fats and oils

b. Steroids like cholesterol

c. Turpentine oil

d. Sex hormones

e. Phospholipids

f. Vitamins like A, D, E and K

g. Waxes

Classification of lipids:

Lipids are classified into the following two groups:

i. Simple lipids ii. Complex lipids

Their detail is given below:

i. Simple lipids:

The type of lipids which produce fatty acids and alcohols on hydrolysis are called simple lipids or triglycerides.”

Examples: Fats, oils and waxes.

ii. Complex lipids:

“The types of lipids which produce alcohols, fatty acids along with some other compounds on hydrolysis are called complex lipids.” Examples: Phospholipids, glycolipids, sulfolipids etc.

Sources of lipids:

There are two main sources of lipids (fats and oils)

i. Animal sources:

Animal fats are particularly present in adipose tissue. Butter and ghee are special type of animal fats which are made from milk. Marine oils are obtained from marine animals like salmon and whales.

ii. Plant sources:

Vegetable oils are mainly present in seeds and nuts of plants e.g. mustard, olive, sunflower, maize etc.

Uses/importance of lipids:

The uses/importance of lipids is given below:

I. As a source of energy:

They are good source of energy and• make the food tasty. One gram of fats nearly contains double energy than one gram of protein or carbohydrates.

ii. Effect on nervous system:

They exert an insulating effect on nervous system which is necessary for proper function of nervous system.

Iii. As thermal insulators in body:

In mammals a layer of fat is present under the skin. This layer acts as thermal insulator which insulates body from excessive heat or cold.

Iv. As a part of protoplasm:

They are present in the protoplasm and cell membrane.

V. As a precursor (basic):

Some lipids act as precursor of very important physiological! Compounds. For example. Cholesterol is the precursor of steroid hormones.

Vi. For cooking:

Butter, oil and ghee are used for cooking and frying food items and for cooking confectionaries.

vii. Protection of some organs:

A protective layer of fats around our heart, kidneys etc. reduce the impact of any external jerk or shock.

Viii. As solvent:

Lipids acts as a solvent for some vitamins like A, D and E.

Q.8: Write a note on fatty acids?

Ans: Fatty Acids:

Fatty acids are carboxylic. Acids with a long chain which may be saturated or unsaturated:

General Formula:

The general formula of fatty acids is R-COOH.

Types:

On the basis of single or double bonds, present in fatty acids, they are of two types:

Saturated fatty acids:

They have carbon-carbon single bonds.

Examples:

  1. Butyric acid (CH3 (CH2)2COOH) present in butter.
  2. Stearic acid (CH3 (CH2)16COOH) present in animal fats etc.
  3. Caprice acid (CH3 (CH2)4COOH) present in goat milk.

Unsaturated fatty acids:

They have carbon-carbon double bonds.

Examples:

i. Myristoleic acid (CH3 (CH2)3CH=CH (CH2), COOH

Ii.Palmitoleic acid (CH3 (CH2)5CH=CH (CH2)7COOH etc.

9. Describe the difference between fats and oils.

Ans. Difference between fats and oils:

Animal and vegetable fats and oils have similar chemical structures. They are trimesters formed from glycerol and fatty acids. However, difference can be made between fats and oils which are given in the table below;

 

Fats

Oils

 

“Those triglycerides which

Contain higher proportion of saturated fatty acid components are called fats.”

“Those triglycerides which

contain higher proportion of

Unsaturated fatty acid
components are called fats.”

 

They are soft solids.

They are liquids.

 

They have high m.p and b.p.

They have low m.p and b.p.

4) Examples:

H-C-O-C- (CH2)16 CH3

1 51.

142 H-C-0-‘,-(CH2)16 CH3

1 9

H-C-0-C-(C1-12)16 CH3 H

Fat (Saturated)

1:4 9

1-1-0–0-C-(CH2) 7 CH-CH (CH 2)7 CH3 1 0

H-C-0-8-(CH2) 7 CH…CH (CH2) 7CH3 3

1 rif

H-0-0-C-(CH2) 7 CH■CH (CH2) 7CH3

H

Oil (unsaturated)

Society. Technology and Science

Vegetable oils have unsaturated molecules. In industry these oils are changed to saturated solid fat (ghee) by the process of hydrogenation. In this process hydrogen molecules are added to the double bond of oils in the presence of finely divided nickel as catalyst at about 250 °C temperature.

10. What are nucleic acids? Describe its composition, types and uses.

Ans Nucleic acids were first discovered in nuclei of WBC’s in 1868 AD. Later on they were discovered in the head of sperm cell by Friedrik Miescher in 1872 AD.

Definition:

“Complex organic compounds consisting of nucleotides which synthesize proteins and transmit characters from parents to offspring’s are called nucleic acids.”

Explanation:

Nucleic acids are found in each and every cell and viruses. They are essential parts of genes. They consist of small units called nucleotides. Most of the nucleotides are biopolymers of nucleosides and phosphate group.

Types of nucleic acids:

Naturally occurring nucleic acids are of two types:

i. Deoxyribonucleic acid (DNA)

ii. Ribonucleic acid (RNA) Composition of nucleic acids:

Nucleic acids consist of small units?!) Called nucleotides. These nucleotides in each of the nucleic acid consist of the following three parts:

Parts of nucleotides:

i. Sugar:

It has five carbon rings which may be ribose as in RNA or deoxyribose as in DNA.

ii. Nitrogenous base:

It is heterocyclic amine which is either purines (adenine and guanine) or pyrimidines (cytosine, thorniness and uracil).

iii. Phosphate group:

It is the third part of nucleic Acids

Functions of nucleic acids:

Nucleic acids perform the following two main functions.

1. Genetic information and protein synthesis:

They store and transmit genetic information. The genetic information, for the cell, is present in DNA molecules in the form of special codes. This information are translated and expressed by synthesis of specific proteins. These proteins perform various functions according to the directions which are given by the codes present in DNA. Thus protein synthesis in cell are completed in two stages i.e. transcription (transference of genetic codes) and translation (the translation of information of codes).

2. Mutation:

“Any sudden chemical change in DNA which could lead to the synthesis of proteins with a disturbed amino acids sequence is called mutation.”

Mutations occur during DNA replication when the chemical structure of genes undergoes random modifications.

Mutation is caused by various mutagens like radiations, chemical agents or viruses.

Majority of changes in DNA are repaired by special enzymes in the cell. However, when the enzymes fail to repair the change, mutation occurs. CXCI.11:

Q. What are vitamins and how are they classified?

Ans: Vitamins;

Origin of word vitamin:

The name vitamin was originally vitamin because the first one that was found was an amine; hence the name vital amine or vitamin was adopted. Later on, it was found that all of them are not amines. So, the “e” was dropped.

Definition:

“Organic compounds that cannot be synthesized by an organism but very essential for the maintenance of normal metabolism are called vitamins.”

Need of vitamins:

Vitamins are required by the body in small amounts to maintain health and function properly. The absence or deficiency of vitamins causes various diseases.

Types/Classification of vitamins:

There are two main types of vitamins:

1. Fat soluble vitamins:

These include vitamins A, D, E and K

2. Water soluble vitamins:

These include vitamins B-complex and vitamin C. Their detail is given below:

1. Fat soluble vitamin:

i. Vitamin A:

Its chemical formula is C20-1300. It is also called retinol. It is a fat soluble vitamin which plays an important role in cell growth, vision and the immune system.

Sources:

Vitamin A is found in green vegetables and fruits like sweet potatoes, pumpkin, spinach, banana, plum etc. It is also found in fish liver oil, eggs, butter and cheese etc.

Vitamin A is not found in plants as such. it is present in the form of pro vitamin such as beta-carotene (a vitamin precursor found in vegetables like carrot, spinach etc.). Vitamin A combines with a protein called posing to produce a light absorbing compound called rhodopsin, which plays a vital role in vision.

Deficiency diseases:

Deficiency of vitamin A causes night blindness, which is inability of a person to see in dim light. Similarly, its deficiency also causes dryness of skin and irritation of eyes.

ii. Vitamin D:

Its chemical formula is C241-1440. It is also called calciferol due to its role in calcium metabolism. Vitamin D helps in the absorption of calcium and phosphate from intestine and deposits it in skeleton.

Sources:

Vitamin D is found in fish liver oil, milk, butter and vegetables. Vitamin D is also manufactured by the skin after exposure to sunrays. Deficiency diseases:

It deficiency causes weakness of bones and a disease called rackets. (Bowed legs and arms). It also causes osteomalacia (softening of bones).

iii. Vitamin E:

Its chemical formula is C29I-14602. It is also called “Tocopherols” which means fertility because it has major role in reproduction. It has different uses for example it is used as antioxidant.

Sources:

Its main sources are green vegetables, corn oil, soya bean oil, egg yolk, liver, bread, rice etc.

Deficiency diseases:

Its deficiency causes a disease known as anemia due to the destruction of cell membrane of RBC by oxidation. People having anemia have symptoms like pale skin, shortness of breath, rapid heartbeat, low vitality, dizziness.

Its deficiency also causes sterility (reproductive system disease).

iv. Vitamin K:

Its chemical formula is C31F14602. It is also called phytomenadione. Vitamin K helps in blood clotting. Without this, bleeding would not stop. Sources:

Its main sources are green vegetables, cheese, liver, meat, egg yolk etc.

Deficiency diseases:

Deficiency of vitamin K causes hemorrhage in which the blood fails to clot and thus the bleeding time is increased.

2. Water soluble vitamins:

i. Vitamin B-complex:

Vitamin B-complex consists of vitamin B1, B2, B3, B5, B6, Biotin, Folic acid and B12 therefore, they are called vitamin B-complex.

Sources:

Vitamin B-complex are found in bread, rice, yeast, milk, meat, liver, fish, seeds, eggs, leafy vegetables, dry peas and beans etc.

Deficiency diseases:

Their deficiency causes skin diseases, tongue and lips inflammation, anemia, bleeding gums and beriberi (nervous system disease).

ii. Vitamin C:

Its chemical formula is C6I-1806. It is also called ascorbic acid. Most of the animals can synthesize it but the human beings cannot due to the absence of enzymes.

Sources:

The main sources of vitamin C are citrus fruits such as lemon, Oranges, grapes, strawberries and fresh green vegetables etc.

Deficiency diseases:

Its deficiency causes scurvy disease which is characterized by pain in joints and bleeding from gums.

Q.12. Write the importance of vitamins?

Ans. Importance of Vitamins:

Vitamins play a vital role in healthy development and growth of our body. For normal body functions, vitamins are necessary. A few important points regarding importance of vitamins are given below:

i. Blood Clotting:

Vitamin K is necessary for blood clotting.

ii. Blood Formation and Immune System:

Vitamin C is necessary for the formation of blood and improvement of immune system.

iii. Vision:

Vitamin A is necessary for vision. It also keeps the cornea moist.

iv. Defense against Carcinogens:

Vitamin E is a defender against carcinogenic effects of certain types of chemicals.

v. Nerve Impulse Regulation:

Vitamin B1 helps to regulate never impulse regulation.

vi. Blood Calcium Regulation:

Vitamin D regulates blood calcium which is necessary for proper growth of bones.

  1. Defense against Diseases:

Vitamins protect us from various diseases like deficiency of vitamin B12 results in the inflammation of the corner of mouth and cracks in lips. Similarly, deficiency of vitamin A cause night blindness, deficiency of vitamin C causes scurvy, deficiency of vitamin D causes rickets, deficiency of vitamin E causes anemia and deficiency of vitamin K causes hemorrhage.

word image 40

A. Choose the correct option.

1. Which one of the following is a disaccharide?

a. Glucose b. Fructose c. Sucrose d. Starch

2. A large number of amino acids polymerizes into

a. Vitamins b. Carbohydrates c. Protein d. Lipids

3. Glycogen is an example of

a. Fats b. Nucleic acids

c. Carbohydrates d. Protein

4. Deficiency of vitamin A causes

a. Scurvy b. Rickets

c. Night blindness d. Aging

5. The compound which is found in every living cell and serves as a centre Of information and control is

N b. amino acid c. DNA d. Glucose

6. Triglycerides are the building blocks of

a. Protein b. Carbohydrates

7. Sugars are Polyhydroxy derivative of

a. Alkyl halides c. ketone

8. Peptide linkage is present in c. Lipids d. Vitamins

b. Aldehyde d. Aldehyde & Ketone

a. Carbohydrates b. Lipids c, Protein d. Vitamins

9. Plants convert glucose into

a. Amino acids b. Lipids

10. All are present in DNA except

a. Deoxyribose c. Nitrogen base c. Protein d. Starch

b. Ribose sugar d. Phosphate unit

1. Differentiate between glucose and fructose?

Ans. Differences between Glucose and Fructose:

The differences between glucose and fructose are given below

Glucose Fructose

,

  1. 1

It is a monosaccharide 1 It is also a monosaccharide

Which is Polyhydroxy but it is Polyhydroxy ketone.

Aldehyde.

 

Glucose needs insulin for Fructose has no need of

It’s metabolizing. 1 insulin for its metabolizing.

 

It has less sweet taste 1 It is sweeter than glucose.

Than fructose.

.

Structure: Structure:

H0
\ ,

ig

H —C—OH

2C—OHHO—C—H 1

H—C—OH 41

H—?-0H

H— 6C—OH
H

Glucose

H

i

H–71 —0H

C=-0 2 1

HO

H—C—OH 41

H—C—OH 51

H—C—OH 6 1

H
Fructose

Write down four uses of lipids.

A. For answer see Question no.7

3. How would you differentiate between simple and complex lipids?

Ans. Differences between Simple and Complex Lipids:

The differences between simple and complex lipids are given below: Simple Lipids Complex Lipids

(1) “The type of lipids which “The type of lipids which produce fa44y acids and produce alcohols, fatty acids alcohols on hydrolysis are along with some other called simple lipids or compounds on hydrolysis are triglycerides.” called complex lipids.”

 

They do not contain They contain phosphates,

phosphates, nitrogenous nitrogenous bases and

 

Bases and sulphates in their molecules.

Sulphates in their’ molecules.

 

They have low molecular

They have high molecular

 

Masses than complex lipids.

Masses than simile Ii. Ids.

 

Examples:

Examples:

 

Fats, oils and waxes.

Phospholipids, glycolipids, sulfolipids

What is meant by denaturing of protein?

Ans. Denaturation:

It is a process in which proteins lose their secondary structure (shape of protein molecules caused by hydrogen bonding) and tertiary structure (folding and bending of proteins caused by R groups) by heat or one chemical substance.

Q.5. how would you classify vitamins?

Ans. For answer see Question no.11 without sources and deficiency diseases.

0.6. Vitamins are vital for us, why?

Ans. For answer see Question no.12

7. Write down the products of sucrose on hydrolysis.

Ans. Products of sucrose on hydrolysis:

Sucrose yields glucose and fructose on hydrolysis. Chemical equation:

Sucrose + Water — Glucose + Fructose

Cl2H22011+H20 –• CH2OH (CHOH) 4COH+CH2OH (CHOH) 3COCH2OH

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

Ans: For answer see Question no.5 heading 2.1

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

Ans. For answer see Question no.11

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

Ans. For answer see Question no.5+6

word image 41

1. What functions do carbohydrates perform in living organisms?

Ans. Eunctkarlsorformed by carbohydrates in living Carbohydrates performs various functions in living organisms. Sore: I of their used are given below:

i. Medical uses:

Constipation and diarrhea are controlled by the use of fibers which are carbohydrates. Similarly, cellulose helps to lower cholesterol level and regulates blood pressure.

Ii. As a source of energy:

Carbohydrates also act as a chief source of energy in living organisms. For example, glucose in the form of glycogen is stored in animal liver and muscles cells. It is converted back into glucose when needed. Plants store excess energy in the form of starch.

Iii. As a structural material:

They act as a structural material for plants.

Iv. As a source of food:

Hydrates serve as a source of food in living organisms.

Q. Distinguish between monosaccharaides, disaccharides and polysaccharides and also give examples of each one.

Ans. or answer sees Question no.3

Q. How are carbohydrates important to living organisms?

. For answer see Question no.4

Q.3 (a) how is proteins important to living organisms?

Ans. Importance of Proteins:

For answer see Question no.5

(b) Describe the nature of bonding in protein?

Ans. For answer see Question no.5

(a) Define the term lipid.

Ans. For answer see definition of lipids in Question no.7

Along with few examples. Tens.

For answer see Question no.9) Distinguish between fats and oils.

Q. List four foods you eat that contain lipids.

Ans. Four Foods Containing Lipids:

The four foods, we eat, containing lipids are given below:

i. coconut ii. Sunflower iii. Peanut iv. Walnut.

Q. How are lipids important to your body?

Ans. For answer see Question no.7

(A).How would you justify DNA as genetic code of life?

Ans. DNA as a genetic code of life:

The genetic information’s for the cell are present in DNA molecules in the form of special codes. This information are translated and expressed by synthesis of specific proteins. These proteins perform various functions according to the directions which are given by the codes present in DNA. Thus protein synthesis in cell are completed in two stages i.e. transcription (transference of genetic codes) and “anslation .the translation of information’s of codes).

Thus, DNA is genetic code of life containing all information of body like size, colour etc. of various organs.

(b).Distinguish between DNA and RNA

Ans: Differences between DNA and RNA:

The differences between DNA and RNA are given below:

DNA RNA

(1) DNA stands for deoxyribose- nucleic acid. RNA stands of ribonucleic acid.

(2) Its structure consists of deoxy ribose sugars, nitrogenous bases and phosphate groups. Its structure contains ribose sugars, nitrogenous bases and phosphate groups.

(3) The nitrogenous bases of DNA are adenine, guanine, cytosine and thymine. The nitrogenous bases of DNA are adenine, guanine, cytosine and uracil.

(4) Three types of RNA’s are present in an organism i.e. mRNA in nucleolus while tRNA and rRNA in

C) O lasm. DNA is present in nucleus, nucleolus, mitochondria and chloroplast.

 

DNA

RNA

 

DNA stands for deoxyribose- nucleic acid.

RNA stands of ribonucleic acid.

 

Its structure consists of deoxy ribose sugars, nitrogenous bases and phosphate groups.

Its structure contains ribose sugars, nitrogenous bases and phosphate groups.

 

The nitrogenous bases of DNA are adenine, guanine, cytosine and thymine.

The nitrogenous bases of DNA are adenine, guanine, cytosine and uracil.

 

Three types of RNA’s are present in an organism i.e. mRNA in nucleolus while tRNA and rRNA in

c o lasm.

DNA is present in nucleus, nucleolus, mitochondria and chloroplast.

(c)Explain the functions of DNA.

Functions of DNA:

For answer see question no.10

6 (a): Define the term vitamin and classify it?

Ans. For answer see Question no.11 without sources and deficiency diseases.

(b). Explain the important sources of vitamins?

Ans. For answer see Question no.11 with sources of all vitamins.

Write down the names of five vitamins and their importance.

Ans. For answer see Question no.12.

2
CLASS 10th CHEMISTRY NOTES CHAPTER 13 BIOCHEMISTRY 7

1. Poly hydroxyl compounds of aldehyde and ketones are called:

(a) Carbohydrates (b) proteins (c) lipids (d) vitamins.

2. Wheat, rice and honey are the sources of:

(a) Vitamins (b) proteins (c) carbohydrates (d) lipids.

3. Is a basic component of paper industry:

(a) Cellulose (b) maltose (c) glucose (d) lipids.

4. Polymers of amino acid are—–

(a) Vitamins (b) proteins (c) lipids (d) carbohydrates.

5. Nucleic acids are of types.

(a) Two (b) three (c) four (d) five.

6. Vitamin is called ascorbic acid:

(a) A (b) B (c) C (d) E.

7. Fats and oils are called .

(a) Carbohydrates (b) lipids (c) proteins (d) vitamins.

8. Is a factor related to blood clotting?

(a) Vitamin A (b) Vitamin B (c) Vitamin C (d) Vitamin K.

9. Drips are administered to the dehydrated and weak patients in clinic and hospitals.

(a) Dextrose (b) maltose (c) fructose (d) glucose.

10. Constipation and diarrhea are controlled by —-fibers.

(a) Protein (b) carbohydrates

(c) glycoprotein’s (d) glycolipids.

11. All the carbohydrates are plants origin except—-which is of animal origin.

(a) Lactose (b) maltose (c) fructose (d) glucose.

12. In protein polymers amino acids are joined together by

(a) Hydrogen bonding (b) peptide linkage

inate covalent bond (d) both a & b.

13. In protein molecules—types of bonding may occur.

(a) 3 (b) 5 (c) 2 (d) 4.

14. All proteins contain—-essential elements.

(A). 0, N (b) C, H, N, S.

(c) C, H, 0, Fe (d) C, 0, Fe, S.

15. Different amino-acids are commonly found in proteins.

(a) 20 (b) 15 (c) 25 (d) 30.

16. Gum disease scurvy is caused by

(a) vitamin-c (b) vitamin-k (c) vitamin-B (d) vitamin-A.

17. Vegetable oils (unsaturated molecules) are converted into saturated solid fat (ghee) by a process called

(a) Halogenations (b) Hydrogenation

(c) Halo hydrogenation (d) Chlorination.

18. The building units of nucleic acids are

(a) amino-acid (b) fatty-acid (c) nucleotide

(d) glycerol.

19. Each nucleotide of RNA, DNA is composed by

(a) Sugar, N-Base, phosphate group

(b) Sugar, amino-acid, Disulphide.

(c) Sugar, N-Base, fatty-acid

(d) amino-acid, glucose, fatty-acid.

20. A sudden change in DNA molecule is called

(a) Mutation (b) guttation (c) wilting (d) plasmolysis.

21. A chemical substance that has a smell or odor is called

(a) Fragrance (b) volatile (c) non-volatile (d)odorance.

22. Night-blindness is caused by the deficiency of

(A) vitamin-A (b) Vitamin-B (c) vitamin-D (d) Vitamin-C.

23. The deficiency of vitamin-D produces a disease called

(a)Rackets (b) measles (c) Scurvy (d) night-blindness.

24. Vitamin-E deficiency cause

(a)Anemia (b) measles. (c) Scurvy (d) night-blindness.

25. In intestine vitamin-K is synthesized by

(a)Protozoa (b) bacteria (c) Ascarus (d) virus.

26. Inflammation of lips, dryness & burning of eyes is caused by .

(a) vitamin-B1 (b) vitamin-B2 (c) Vitamin-C (d) Vitamin-A.

27. Vitamin-C is chemically known as .

(a) Acetic acid (b) ascorbic acid (c) steric acid (d) retinol.

28. Mutation is a chemical change in

(A) Lipid (b) protein (c) RNA (d) Genes.

29. Fructose is a ploy-hydroxyl derivative of .

(a) Ketone (b) aldehyde (c) alkyl (d) amine.

30. Which one of the following vitamin is water soluble?

(a) A (b) C (c) D (d) K

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