Question

Aquaporins are proteins embedded in the plasma membrane that allow water molecules to move between the extracellular matrix and the intracellular space. Based on its function and location, describe the key features of the protein’s shape and the chemical characteristics of its amino acids.

Short answer

Aquaporins are the transmembrane proteins that are embedded in the plasma membrane and help in the transport of fluids.

Step-by-step solution

Introduction

Aquaporins are the special protein channels in the plasma membrane which allow the water molecules to pass across the membrane into and out of the cell.

Explanation

Aquaporins are made up of a bundle of six transmembrane alpha helixes. Since it is a protein, it has the carboxyl and amino end, both of them are present facing inside the cells towards the cytoplasm. The transmembrane helices are joined together by 5 loops from A-E. Loops B and E form the hydrophobic loops which dip halfway into the membrane. The protein's hydrophilic ends are projected towards the extracellular and intracellular fluid, along with the hydrophilic channel at the middle thus allowing only water molecules to pass through it by the process of osmosis.