ADVERTISEMENTS:
Here is a compilation of essays on ‘Nutrients’ for class 7, 8, 9, 10, 11 and 12. Find paragraphs, long and short essays on ‘Nutrients’ especially written for school and college students.
Essay on Nutrients
Essay Contents:
- Essay on Carbohydrates
- Essay on Proteins
- Essay on Fat and Lipids
- Essay on Minerals
- Essay on Vitamins
ADVERTISEMENTS:
ADVERTISEMENTS:
1. Essay on Carbohydrates:
a. Carbohydrates, the most abundant organic compounds in nature, are the chief source of energy.
b. Plants produce carbohydrates through a process called photosynthesis, wherein the chlorophyll of the plant uses sunlight to synthesis carbohydrate from carbon dioxide and water.
c. These are made up by carbon, hydrogen and oxygen—CHO.
ADVERTISEMENTS:
Classification of Carbohydrates:
(1) Monosaccharides:
Or Simple sugars, compounds with one carbohydrate unit e.g. Glucose, Fructose and Galactose.
(2) Disaccharides:
Disaccharides are the compounds with two hexose molecules e.g. Sucrose, Maltose, Lactose.
(3) Polysaccharides:
Polysaccharides are complex carbohydrates with a relatively high molecular weight—they may contain as many as 2,000 simple carbohydrate units arranged in long chains of either straight or branched structure e.g. Starch, Cellulose, Dextrins, Glycogen.
Source of Carbohydrates:
Common sources of carbohydrates are:
ADVERTISEMENTS:
(1) Cereals and Millets
(2) Pulses and Legumes
(3) Tubers
(4) Nuts
ADVERTISEMENTS:
(5) Fruits
(6) Sugars
(7) Honey
Functions of Carbohydrates:
ADVERTISEMENTS:
(1) Source of energy
(2) Protein sparing substance
(3) Regulation of fat metabolism
(4) Regulation of gastrointestinal functions
ADVERTISEMENTS:
(5) Synthesis of B-complex inside intestine
2. Essay on Proteins:
1. 1838, Muller a Dutch chemist, recognised nitrogenous compound of biological origin.
2. Berzelin suggested name as ‘Proteo’ meaning to take first place.
Composition of Proteins:
1. Proteins are complete nitrogenous organic compounds built up of smaller units called amino acids.
ADVERTISEMENTS:
2. All proteins contain Carbon, Hydrogen and Nitrogen. Most of them contain sulphur and others contain phosphorus.
3. Some specialised proteins contain other trace element like Iron, Iodine and Copper.
4. Lipids combine with proteins to form lipoproteins.
5. Vitamins like thiamine and pantothenic acid combine with proteins to form enzymes.
6. Proteins contain an average of 16% nitrogen. Presence of nitrogen distinguishes proteins from carbohydrate and fats.
Classification of Proteins:
ADVERTISEMENTS:
(1) Simple Proteins:
These contain amino acids only e.g. Albumins and Globulins.
(2) Conjugate Proteins:
Simple proteins combine with non-protein substances e.g. phosphoprotein casein (milk protein). Nucleoproteins (Protein of cell nuclei) when hydrolyzed by acids, alkalies or enzymes they yield amino acids and their amino acids.
(3) Derived Proteins
These proteins are formed by the action of enzymes on simple and conjugated proteins e.g. Peptones, or Proteoses.
Essential Amino Acids:
Human body requires 22 amino acids out of them, 8 cannot be synthesized in sufficient quantity, so these are essentials to be taken in food-protein:
1. Leucine
2. Isoleucine
3. Lysine
4. Methionine
5. Phenylalanine
6. Threonine
7. Tryptophan
8. Valine.
Mutual Supplementation of Proteins:
Some foodstuffs consumed by human being deficient in specific amino acids and other foodstuffs by other amino acids. When mixed foods are consumed mutually supplementation takes place e.g. cereal proteins are deficient in lysine and threonine and pulse protein in methionine. These are known as LIMITING AMINO ACIDS—when cereals and pulses are eaten together, amino acids are supplemented mutually.
Amino Acid Imbalance:
Any amino acid present in excessive amounts have been found to interfere metabolism of other nutrients resulted into an outcome of disease called as amino acid imbalance, e.g. Jowar (Sorghum) eaters are prone to pellagra—’Niacin’— deficiency disease) due to presence of an excess amount of leucine in jowar interfere conversion of tryptophan to niacin leads into pellagra.
Functions of Proteins:
1. Maintenance and growth.
2. Body building and repair.
3. Regulation of body processes.
4. Proteins as source of energy.
5. For the formation of specific substance e.g. Antibodies, plasma protein, haemoglobin, enzymes and hormone.
Protein Requirements:
Protein requirement is variable from individual to individual due to following variables:
1. Age.
2. Sex.
3. Physiological state, e.g. infant.
4. Infections, worm infestation and other diseases.
5. Emotional disturbances and stress situations.
6. Net protein utilization of dietary proteins.
Daily Requirement:
Infants:
Deficiency Diseases Due to Lack of Protein:
(1) Protein energy malnutrition is public health problem among the children in our country which is developing as ‘food gap’ rather than protein gap serve of PEM are Marasmus and Kwashiorkor.
3. Essay on Fat and Lipids:
a. Lipids are organic compounds made up of Carbon, Hydrogen and Oxygen. Also contain other elements like phosphorus and nitrogen.
b. These are composed of fatty acids.
Functions of Fat & Lipids:
(1) Richest source of energy—1 gm. provides 9 Kcal of energy
(2) Utilisation for soluble vitamins A, D, E, & K.
(3) Fats help in lubricating the gastrointestinal tract and a diet rich in fat has a higher satiety value.
(4) Source of essential fatty acids.
(5) It provides support and safety to VISCERA i.e. heart, kidney and spleen etc.
(6) Fat beneath the skin provides insulation against cold.
Classification of Fat & Lipids:
(1) Simple Lipids:
Consist mainly of glycerides of fatty acids. In a triglyceride three molecules of fatty acids can be of the same acid known as simple triglycerides or of different acids known as mixed triglycerides.
(2) Compound Lipids:
Contain other radicals in addition to the fatty acid radical e.g. phospholipids are those lipids which contain phosphate. Main—Lecithin and Cephalo Lipoproteins are compound lipids containing a protein molecule in the triglycerides.
(3) Derived Lipids:
This group includes fatty acids, alcohol, carotenoids and fat-soluble vitamins like A, D, E and K.
Daily Requirement:
a. Daily requirement of essential fatty acid is 5 gm.
30% energy intake would be derived from fat sources.
b. Saturated fat consumption should not be more than 10%.
Essential Fatty Acids:
1. These are the fatty acids essential for the promotion of growth and maintenance of dermal integrity:
a. LINOLEIC ACID
b. LINOLENIC ACID
c. ARACHIDONIC ACID
2. Essential fatty acids are present in fair amount in vegetable oil while these are least in animal source.
3. Deficiency causes PHRENODERMA.
Invisible Fats:
1. Fats which are present in foodstuffs and not easy to estimate called invisible fats e.g. milk, eggs, fish, meat and cereals.
2. Fats which are very easily estimated in the amount of consumption e.g. Ghee, Oil and Vanaspati Ghee.
3. The total for intake—both visible and invisible — are approx. 40 grams daily, out of it about 50% from invisible fat source.
Hydrogenation:
Hydrogenation is a process by which Vegetable oil is converted into vegetable fat by mixing Hydrogen Gas in the presence of nickel catalyst. Vanaspati Oil H2 NI: Vanaspati Ghee.
Advantages of Hydrogenation:
1. Ghee-like consistency.
2. Quality can be maintained longer period.
Disadvantages of Hydrogenation:
It reduces presence of essential fatty acids e.g. groundnut contains about 28% of essential fatty acids; on hydrogenation EFA reduced up to 2%.
Refined Oil:
Process removes rancid material and free fatty acids from oil. So, quality and taste of oil is improved; such oil is called refined oil.
Energy Requirements:
1. In nutrition calorie is synonym of energy.
2. Energy required by system for following works
(A) Basal Metabolism:
Required for vital functions of body e.g. respiration, blood circulation, maintenance of body temperature:
For Male—58.1 Kcal per square metre per hour.
For Female—32.9 Kcal per square metre per hour.
Indian Reference Man:
Who is between 20 and 39 years of age and weight of 60 kg. He is free from disease and physically fit for active work; and hrs of occupation of moderate activity, spends 8 hours on bed 4 to 6 hrs sitting and moving around 2 hours in walking and household duties (ICMR 1990).
Indian Reference Woman:
Age between 20 and 39 years, healthy and weight 50 kg involving 8 hours general household work, in light industry or in any moderate work, 8 hours on bed 4 to 6 hours moving around with light activity and 2 hrs. other work.
(B) Energy Expenditure—Off-Work:
Energy required for off-work like sitting standing, dressing, walking etc.
i. For Males — 1,220 Kcal.
ii. For Females — 826 Kcal.
(C) Energy during Fecal Loss:
10% of recommended energy is required for fecal loss.
(D) Energy Expenditure for Work:
ICMR recommendations about energy expenditure during working period:
Consumption Unit:
When energy requirement of a group of people is to be calculated, it is assessed in terms of the average man which is reckoned as 1.0 coefficient or consumption unit.
The energy requirement of the rest members of the group is adjusted:
4. Essay on Minerals:
Body contains about 24 minerals. The quantity of minerals is required in different amounts for total system.
Functions of Minerals:
(1) Formation of bones and teeth.
(2) Maintenance of osmotic pressure
(3) Specific functions e.g. Iron for the formation of blood, iodine for the formation of thyroxine; calcium for blood coagulation etc.
(4) Maintenance of Acid-Alkali balance.
Classification of Minerals:
(A) Major Elements (Macro-Minerals):
Minerals which are required by the body in Mgs (in more amount) e.g. Calcium, Phosphorus, Sodium etc.
(B) Trace Elements (Micro-Minerals):
These mineral required by the body in trace amount in micrograms e.g. Iron, Iodine, Copper and Zinc etc.
5. Essay on Vitamins:
a. Vitamins play vital role in various metabolic activities.They control various vital activities of the system.
b. Deficiency of vitamins develops various symptomatics.
c. Essential organic compounds as nutrients.
d. They don’t yield energy.
e. They include:
(i) Fat-soluble vitamins-viz. vitamin A, D, E & K.
(ii) Water-soluble vitamin-viz., B complex & ‘C’.
