Give a scientific reason: Although the molecular weight of lipids is less than $1000 \text{ Dalton}$,they are included in biomacromolecules.

(D) $\Rightarrow$ Compounds with a molecular weight less than $1000 \text{ Dalton}$ are classified as micromolecules,while those with a higher molecular weight are called macromolecules.
$\Rightarrow$ Proteins,nucleic acids,and polysaccharides are true macromolecules found in the acid-insoluble fraction.
$\Rightarrow$ Lipids have a molecular weight of less than $1000 \text{ Dalton}$,which would typically classify them as micromolecules.
$\Rightarrow$ However,during the process of grinding tissue in trichloroacetic acid,the cell membrane and other membranes are broken into vesicles that are not water-soluble.
$\Rightarrow$ Consequently,these lipid-containing vesicles are separated along with the acid-insoluble fraction (macromolecules) rather than the acid-soluble pool. Therefore,they are studied along with biomacromolecules.