The skin is made up of three layers, each with its own important parts. The layer on the outside is called the epidermis
Answer:
Thd sequence of amino acids it has.
Answer;
Cell membrane
A cell membrane acts as a boundary that separates things that are inside the system from those that are outside the system.
Explanation;
It is a thin semipermeable structure that surrounds the cytoplasm of a cell.
The membrane functions to protect the integrity of the internal environment of the cell by allowing selective movements of materials in and out of the cell.
The membrane consists of a phospholipid bilayer with proteins embedded in it.
I think the correct answer from the choices listed above is option B. Keratin is the protein in mammals which shows only a primary and secondary structure. Keratin is a fibrous protein forming the structural constituent of hair, feathers, hoofs, claws and many others.