What is Assimilation?

Introduction

Assimilation is the process by which living organisms convert food into vitamins, minerals, and other chemicals that are required by the body to perform various functions. Energy is required by the body to perform its cellular processes. This energy is supplied through digested food.

The food that we eat is absorbed and converted into chemicals which flow through the bloodstream to different parts of the body.

Living organisms take in nutrients such as vitamins, minerals, carbohydrates and other chemicals from different types of foods and utilizes them to fulfil the energy demand required by the body to stay alive. This is known as assimilation of food.

Definition

Assimilation refers to the conversion of nutrients taken in from food into usable form that can be utilized by the tissues and organs. This mainly occurs after the process of digestion. In plants, photosynthesis, nitrogen fixation, and absorption of raw materials are two main processes by which plants derive their nutrition.

Examples of Assimilation

Some examples of assimilation are given below −

Photosynthesis

It is the process by which carbon dioxide and water in the presence of sunlight and chlorophyll pigment are converted into organic molecules in plant cells.

Nitrogen Fixation

Nitrogen present is converted into organic molecules needed by the plants. Nitrogen fixation is done by symbiotic bacteria living in the roots of Leguminous plants. Examples of leguminous plants are soyabeans, peas, alfalfa, etc.

Magnesium Supplements

Orotate, oxide, sulphate, citrate, and glycerate are some structurally similar chemicals. Oxides and sulphates are insoluble in water and do not enter the blood stream, while orotate and glycerate have normal exiguous liver conversion.

Absorption of Nutrients

The absorption of nutrients into the body after digestion and its transformation in biological tissues and fluids.

Impact of Assimilation

Solar energy is the primary source of energy for all living creatures in the universe. The living organisms need energy to fulfill the various physiological functions.

There are two types of organisms,autotrophic organisms and heterotrophic organisms.

The organisms that prepare their own food, with the help of light, water and carbon dioxide are known as autotrophic organisms.

The process by which inorganic carbon compounds are converted into organic compounds such as carbohydrates, amino acids, proteins and other carbon compounds are called Carbon fixation. This is also referred to as carbon assimilation.

The autotrophic organisms can further be classified into −

Photoautotrophs: Those organisms that depend on sunlight for their energy, and

Litho autotrophs: Those organisms that depend on inorganic oxidation processes for their energy.

Heterotrophic organisms are those organisms that are unable to produce their own food. Hence, they rely on external sources for their energy supplies. They assimilate the organic matter present in the food that they eat. During assimilation, complex proteins and carbohydrates are converted into simpler glucose and amino acids so we can say that assimilation plays an important role in the movement of digested food particles into various cells of the body where energy is required.

Assimilation in Plants

The plants require nitrogen for their survival and growth, this is supplied by either fertilizers or when the soil absorbs nitrogen from the atmosphere. Assimilation in plants start when Nitrogen is absorbed by the soil. The bacteria present in the soil converts the nitrogen into ammonia, which in turn is converted into nitrates that can be easily absorbed by the roots of the plants. Due to this absorption cycle, amino acids, nucleic acids and chlorophylls are built.

Nitrogen fixing bacteria on leguminous plants

The process of assimilation is also utilized during carbon fixation, which is known as carbon assimilation. Thus, plant assimilation includes nitrogen assimilation and carbon assimilation.

Assimilation in Invertebrate

In invertebrates, eating and digestion are the two important processes that is involved in assimilation. Invertebrates take in and assimilate nutrients in different ways. Sometimes, the nutrients are absorbed straight away from the host digestive system, like that in case of Tapeworms.

In sponges and corals, the food particles are directly take in through the process called phagocytosis. Nematodes have a is single long digestive tract extending from mouth to anus. Hence, it can be concluded that all forms of invertebrates take energy from nutrients. One way or another, they all employ assimilated nutrients for their growth and energy.

Assimilation in Humans

Assimilation in humans is a complex phenomenon. It starts from digestion of food. Hence, in order to understand the concept of assimilation of nutrients, we need to understand the process of digestion. The food is taken in from the mouth where the larger food particles are converted and assimilated into smaller ones.

For example, if someone eats a sandwich, it first enters the mouth. The sandwich is then chewed (masticated) to allow passage into the pharynx or throat. Some digestion of food occurs in the oral cavity, with the incorporation of saliva and the action of the teeth, tongue, and gum, the food is converted into bolus.

The bolus passes from the pharynx, through the esophagus, and to the stomach, where it is mixed with gastric juices and converted into a soluble, semi-liquid material called chyme that can be further digested in the small intestine. The digestion of carbohydrates and proteins start in the stomach.

The small intestine is the most important organ of the digestive tract because it produces digestive enzymes. The conversion of fats, carbohydrates, and proteins into simple organic compounds primarily occurs there. The absorption of nutrients and water also occurs in the small intestine.

As the primary source of energy for the human body is glucose, after its absorption in the small intestine, glucose is transported to the liver, where it is stored. The large intestine, or colon, receives enzymes from the small intestine and functions by absorbing water and salts from digested food. It also stores waste products later excreted through the rectum from the anus. Hence, we can say that the process of assimilation in human bodies occurs in the small intestine.

Malabsorption

Assimilation of food is a necessary process that provides energy to maintain all functions of the body. The major role of the small intestine in the process of digestion is to absorb the nutrients from the food that is eaten and to deliver them to the cells. There are many syndromes which may affect the smooth working of the bowel. Hence it is known as malabsorption syndrome.

In malabsorption disorders, the intestine is unable to absorb and assimilate micro as well as macronutrients. This is mostly due to damage in the intestine. The damages in the intestine may be caused due to excessive use of medicines, radiation therapy, lactose deficiency, and injured intestine lining. This disorder can be treated by altering the diet, taking vitamins and enzyme supplements and avoiding dairy products.

Conclusion

It can be concluded that assimilation is mandatory for the growth, health, and reproduction of all organisms. More than 90% of assimilation of nutrients (that is the absorption of protein, carbohydrates, vitamins, and minerals) is achieved in the jejunum. Later, the absorption of water, bile salts, and some excessive vitamins are completed in the ileum.

The process of assimilation is affected by various factors including the quantity and composition of the food eaten, the time gap between the meals, the age, and the change in cell concentration and structure.

FAQs

Q1. What is assimilation?

Ans. Assimilation is the process wherein the nutrients are integrated into the biological systems of the organism.

Q2. What are Autotrophs?

Ans. Autotrophs are organisms that produce their food via assimilating light, water, and carbon dioxide.

Q3. Which human biological systems is chiefly involved in biological assimilation?

Ans. Digestive system is involved in biological assimilation in Humans.