AUTOTROPHIC NUTRITION-TEXT

AUTOTROPHIC NUTRITION

BIOLOGY

CBSE-VII

Organisms which exhibit autotrophic nutrition are 

called Autotrophs. These organisms are able to synthesise their nutrients from simple inorganic compounds.

They require minerals, water and carbon dioxide for their growth. They are capable of converting carbon dioxide into various complex organic compounds.

However, they require energy for this purpose. Depending on how they obtain the energy for converting carbon dioxide to organic compounds, there are two types of autotrophs – photoautotroph and chemoautotroph.

PHOTOAUTOTROPHIC ORGANISMS: 

Several bacteria(such as green bacteria, purple bacteria and cyanobacterial) can use light as a source of energy and synthesise complex organic molecules.

Similarly, All the algae and higher plants use light as source of energy. These autotrophic organisms are called photoautotrophic organisms

(photo=light.)

These organisms have special pigments is their body to trap the light energy which drives other reactions.

CHAEMOAUTOTROPHIC ORGANISMS: 

Second group of autotrophs are chemoautotrophs. These organisms obtain energy by oxidizing simple inorganic compounds. 

Such as hydrogen, iron containing compounds, sulphur, hydrogen sulphide, ammonia, nitrite, and other nitrogen containingcompounds. However, all these organisms require carbon dioxide as a source of carbon atoms.

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NANDITHA

Autotrophic, Heterotrophic and Mixotrophic Nutrition -TEXT

Autotrophic,Heterotrophic and Mixotrophic Nutrition

All the living organisms require a continuous supply of carbon containing compounds(also called principal carbon) for growth and for building their body structures. 

Energy is also required to maintain their daily activities and it is derived by oxidizing either organic or inorganiccompounds. Chemical compounds required for body building and for energy production are called nutrients. Intake of nutrients into the body by an organism is called nutrition.

Nutrients may be very simple or very complexinorganic or organic compounds. Different organisms require different types of nutrients. 

For example, several bacteria can survive with a supply of few inorganic salts. Plants use water and carbon dioxide and synthesize carboncompounds like carbohydrates. 

They also use simple nitrogen and sulphur containing compounds to synthesize complex molecules required for their growth. In contrast, amino acids, fatty acids and vitamins for their survival.

They do not have the capacity to synthesise several chemical compounds required for their growth. They depend on other organisms for the supply of these nutrients.

All the nutrients required by an organism are usually obtained through the food they consume. Hence, several times, intake and utilization of food is considered to be similar to nutrition.

Differentorganisms use different methods to obtain their nutrients, especially of carbon source. Autotrophic, heterotrophic and mixotrophic nutrition are three modes by which organisms obtain their principal source of carbon.

THANKYOU,

NANDITHA

COMPONENTS OF FOOD & DEFICIENCY-CBSE VI