The final consumers in many food webs are
(1)autotrophs
(2)hosts
(3)herbivores
(4)carnivores

The answer to this question would be: (4)carnivores
Food made by autotrophs which makes them placed first in food webs as they produce food. After that, the herbivore can digest the food made by autotroph, makes them places as the first consumer. Carnivores is the organism that eats meat, makes them the last consumer.

Lipid because of the high percentage of carbon to carbon bonds, which store more energy than other bonds.