The process of intake of nutrients and its utilization by an organism is called nutrition. **

Nutrient is a substance that provides nourishment essential for the maintenance of life and for growth. **

Proteins are the macromolecules formed by bonding together many amino acids. 16

Glucose, a type of carbohydrates is oxidized step by step in the cells for production of energy in the form of ATP. This is called as cellular respiration. **

Aerobic respiration is the process of producing cellular energy involving oxygen. **

Glycolysis is a process in which a molecule of glucose is oxidized step by step and two molecules of each i.e. pyruvic acid, ATP, NADH2 and water are formed. **