2 What is the function of proteins in the cell membrane? F Facilitate the movement of particles across the cell membrane
G Receive chemical signals from other cells to begin a process in the cell
H Code for specific structures found in the cell membrane
J Create a hydrophobic layer that forms a barrier between the inside and outside of the cell

Answer is F: Facilitates the movement of particles across the cell membrane.

Types of proteins found in the cell membrane includes channel and carrier proteins, both which are involved in the process of facilitated diffusion where they help facilitate the movement of large or polar molecules across the membrane.

The sarcoplasmic reticulum is a specialized type of smooth ER which regulates the calcium concentration in the cytoplasm of striated muscle cells during muscle contraction.