Which of the following statements about integral proteins in

Which of the following statements about integral proteins in the plasma membrane is false? Most integral proteins have a hydrophobic region which holds them in the membrane. Most extend all the way through the membrane. They are located on the outside of the membrane phospholipids. They determine which molecules are transported through the membrane.

Solution

Answer:

3). They are located on the outside of the membrane phospholipids

Integral Proteins

Integral proteins are embedded within the lipid bilayer. They cannot easily be removed from the cell membrane without the use of harsh detergents that destroy the lipid bilayer. Integral proteins float rather freely within the bilayer, much like oceans in the sea. In addition, integral proteins are usually transmembrane proteins, extending through the lipid bilayer so that one end contacts the interior of the cell and the other touches the exterior. The stretch of the integral protein within the hydrophobic interior of the bilayer is also hydrophobic, made up of non-polar amino acids. Like the lipid bilayer, the exposed ends of the integral protein are hydrophilic.

Transport proteins are integral transmembraneproteins. They exist permanently within and span the membrane across which they transportsubstances. The proteins may assist in the movement of substances by facilitated diffusion or active transport.