Well, to put it to the simplest way I can get it. Protein acts as a car engine because it gives us the energy to go and do things like a car engine gives a car the will to move.
        
             
        
        
        
Answer:
The size is reduced as 80-95% of the available energy at one trophic level is not transferred to the next
Explanation:
There is loss of energy as it is transferred between trophic levels. The decrease in energy as it moves up the pyramid is due to energy loss as metabolic heat when one organism is consumed by another from the next level as it moves up the trophic levels.
 
        
             
        
        
        
Cells build carbohydrate polymers by using energy to form glycosidic linkages, the bonds between monosaccharides. A dehydration synthesis reaction forms a bond between carbon atoms in two monosaccharides, sandwiching an oxygen atom between them and releasing a water molecule. Hope this helps!