Chapter 14 - Introduction to Metabolism - Exercises - Page 475: 1

Hetrotrophic organisms cannot synthesize their own food and are therefore dependent on others for the availability of food and organic compounds like vitamins which is essential for metabolism. Where as autotrophic organisms are the ones who can synthesize their own food and organic compounds are therefore independent of the external supply of organic compounds. This is the reason why heterotrophic organisms require vitamins and autotrophic organisms dont.

Hetrotrophic organisms cannot synthesize their own food and are therefore dependent on others for the availability of food and organic compounds like vitamins which is essential for metabolism. Where as autotrophic organisms are the ones who can synthesize their own food and organic compounds are therefore independent of the external supply of organic compounds. This is the reason why heterotrophic organisms require vitamins and autotrophic organisms dont.