‘ The absorption of food by living organisms to stay alive, healthy, to grow and reproduce is known as nutrition’. The food we intake performs various functions in our body. It helps in movement, cell’s synthesis, for the removal of waste products from the body. All the living organisms are categorized in such a way that they can get their food from their ecosystem in a sequenced manner. Let’s first discuss this pattern.


Plants uses sunlight to produce their own food. They utilizes the sunlight to convert the light energy in to chemical energy. This converted energy is stored in the form of ATP (Adenosine triphosphate); a molecule that store and transfer the energy in cell or NADPH(Nicotinamide Adenine Dinucleotide Phosphate Hydrogen); use to give electrons and hydrogen during enzymes catalytic process. Conversion of light energy in to chemical energy is known as photosynthesis.

Chlorophyll based chlorophototrophy and rhodopsin based retinalophototrophy are two types of phototrophy. In chlorophyll based chlorophototrophy, occurs in cyanobacteria, proteobacteria, chlorobi, chlorofexi and fermicutes. All these produce two types of pigments, chlorophyll and bacteriochlorophyll. It is further separated in to two parts. These are oxygenic and anoxygenic photosynthesis.


Chemoautotrophs can synthesis their organic molecules from carbon fixation. 


Organisms that takes water, carbon dioxide and minerals from their environment to grow are autotrophic.


Organisms that takes their food from other plants and animals are said to be heterotrophic.

Nutrition in plants:

With the help of photosynthesis plant makes their own food. The food factory of a plant is leaf. Vessels transport the water and minerals to the plant that helps to grow the plant and synthesize the food. A green pigment called chlorophyll catch the sunlight for leaves, water and carbon dioxide are used to produce carbohydrates and oxygen. So the plant prepare it’s food in presence of sunlight. Some plants are heterotrophic. They are classified according to their mode of nutrition. 

In parasitic mode of nutrition a parasite live on or in the body of other organism and takes it’s food from there. Sometimes it is harmful for the host and sometimes not. A parasite may transfer disease in humans and animals.

In insectivorous nutrition, the plant gets it food from the insects. For example a pitcher plant eats insects. At the edges of this plant has a sticky and sweet substance which attracted the insects. The insect get stick to the substance and after sucking it become unconscious few minutes later. As the insect fall in to the plant the sensor present in pitcher plant alerts the lid at the top and it suddenly closed. It also known as carnivorous plants. By the secretion of digestive juice it digest the insect and absorb nutrients from it. These kind of plants mostly grow where there is lack of minerals in soil.

In saprotrophic nutrition, the plant take food from the dead and decaying plants and animals. These are tabular tubes grow in the soil. These hyphae takes nutrients from dead organic matter and grow. Mushrooms are the example of this type of nutrition.

In symbiotic nutrition, the two organisms share their shelter and nutrition mutually. It may be beneficial or may be not for both of. Leguminous plants are example of symbiotic nutrition. It is of three types first mutualism (in which both organisms benefits), commensalism ( in which only one benefits other one may or may not) and Parasitism ( one benefits and other harms).

Macronutrients are required by plants in large amount e.g. carbon, magnesium, hydrogen, and oxygen, nitrogen, magnesium, potassium etc. And nutrients that are required in small amount are micronutrients e.g. molybdenum, boron, chlorine, zinc etc. Plants show abnormality if any of these is not available.

Role of macronutrients:

Phosphorus is a coenzyme, important for seed germination, photosynthesis and for the formation of proteins.

Potassium reduce water and other gasses by regulating the opening and closing of stomata.

Sulphur is the component of protein, enzymes and vitamins.

Calcium is the structural component of cell wall and activate the enzymes.

Role of micronutrients:

Iron is vital for the photosynthesis procedure and also actives the enzymes.

Molybdenum reduce the nitrate to ammonia and take part in building amino acids.

Boron transport the sugar in cell, take part in cell division and synthesize certain enzymes.

Manganese involves on plants respiration and nitrogen metabolism.

Zinc is required to plant in large number of enzymes.

Chlorine helps in osmosis of water.

What is the role of magnesium and nitrogen in plants?

Nitrogen is important in the growth of stem and leaf growth. And is also a major component of amino acids and chlorophyll. Most of the plants take nitrogen throughout their lives and as the growth of plant increases, the need of nitrogen amount also increases. If the amount of nitrogen exceed to higher level the plant may delay flowering and fruiting. Deficiency of nitrogen causes the stunt growth and yellowing of leaves.

As we know magnesium is a macronutrient and major element of chlorophyll. In addition, very important in the function of enzymes for the production of carbohydrates, fats and sugars. It also contributes in plants growth and protein synthesis. It is also vital for the seed germination and formation of nuts and fruits. The decline of magnesium may defects the plant by wilting of leaves and let them yellow with green vein which is called interveinal chlorosis.

The growth and development of a plant depends upon the concentration of all the above nutrients in sufficient amount otherwise if there is any nutrient lacking, plant will show a stunt growth, dwindle in plant production and fertility. For agricultural sector nutrients are much pivotal to maintain the productivity. Because of certain soils it is harder for the plant to absorb such nutrients, sometimes these are not available to the soil or not the form to carry by the plant. Water content and pH may intensify these issues.

Nutrition in humans:

Human beings need nutrients to stay healthy, for normal growth, aging and to reduce the risk of chronic disease. Seven main nutrients that the body needs are carbohydrates, fats, proteins, minerals, vitamins, fiber and water. Lipids and nucleic acid is also included.


It is the main source of energy. It play important role to maintain the health of kidneys, brain, heart muscles and central nervous system. Carbohydrates have positive aspects on our body mostly but if we take in large amount it may affect. Three main types of carbohydrates are starch, sugar and fibers. Fibers are mostly present in bread, juicy and plump fruits. Starch is available in grains legumes, corn, potato and rice. While we get sugar from the vegetables, fruits, milk and honey. Fibers help in digestion of food and maintain the blood cholesterol levels. Benefit of this nutrient is that it we can store it in our muscles and liver to use when we are not taking carbohydrates in regular amount. According to the research, the consumption of fibers by the adult should be 130 grams, 25 grams for women and 38 grams for men in daily routine. Decrease in take of this may results in bad breathing, fatigue, headache, constipation and weakness.


Proteins perform very important rules in human body. Proteins help in repairing our body tissues and muscles and build up the new cells. Proteins are made up of amino acids and make chains by joining together. Our body needs proteins to grow. People recovering from illness and injures require more amount of protein. Protein enzymes help in biochemical reactions in cell. Hormones are also type of protein. These chemical messengers communicate between organs, tissues and cells. For example hGH ( human growth hormone ) restorative the growth of tissues and bones. Other types of proteins are following.

Keratin is present in our hair, nails and skin.

Collagen is the structural protein of ligaments, tendons, skin and bones.

Elastin is highly elastic in nature. It allows the organs to become to their original shape after stretching and contraction. For example uterus, lungs and our arteries etc.

The two proteins albumin and globulin helps to maintain the body fluids.

Proteins help to fight against infections by producing antibodies. Some proteins transport the substances with in or out of the cell. For example hemoglobin carry oxygen from lungs to the each single cell of our body.

Ferritin stores iron for the body.

There are plethora of advantages of proteins intake. It prevents carving. Good for the bones. Lower the blood pressure, maintain the body weight and increase the strength.


Vitamins help in growth, development and cell functioning. There are 13 important vitamins.

  1. Vitamin A helps in maintenance of teeth, bones, tissues and skin.
  2. Vitamin C is necessary for the absorption of iron in body and in healing of wounds.
  3. Vitamin D absorb calcium which is pivotal for the strength of bones.
  4. Vitamin E helps to form red blood cells.
  5. Vitamin B12 helps to maintain the central nervous system and form red blood cells too.
  6. Niacin helps to maintain the skin and nerves healthier.
  7. If we take low quantity of vitamins, we may face increase in risk of health issues like heart diseases, cancer and osteoporosis.
January 27, 2021
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