Membrane synthesis in the cell requires the regulation of growth for both halves of the bilayer and the selective retention of certain types of lipids on one side or the other. which group of enzymes accomplishes both of these tasks

Flippases.

Explanation:

Cell membrane is made of lipid bilayer and proteins are inserted or span the bilayer. Carbohydrates are attached in association with lipids and proteins in the bilayer membrane.

The enzymes are important for maintenance of the proper structure and function of the membrane. Flippase are the enzymes located in the membrane and belong to ABC transporter family. This enzyme maintain the growth and regulation of halves of the bilayer and transport lipids from one site of the membrane to the another site.

Thus, the answer is flippase enzyme.

i need an image of the diagram