Type III integral membrane proteins are characterized by:

Type III integral membrane proteins are characterized by having connected protein helices that form a structure allowing them to span the lipid bilayer of the membrane. This configuration is significant because it allows these proteins to interact with both the extracellular environment and the cytosolic side of the membrane, facilitating various biological functions, including transport, signaling, and enzymatic activities.

The connection between helices implies that the protein's structure is often well-defined, and these segments can be closely packed within the membrane, contributing to the protein's stability and functional interactions. This characteristic is crucial for proteins that require a specific orientation or conformation to fulfill their roles effectively.

In contrast, the other options describe different types of membrane-associated features or configurations. For example, the presence of lipid anchors refers to proteins that are attached to membranes through lipid molecules, which is not a defining feature of type III proteins. Glycosylation signifies that carbohydrates are attached to the protein, commonly found in other classes of membrane proteins but not exclusively indicative of type III proteins. Unconnected protein helices would indicate a different structural arrangement, which does not apply to the classifications expected of type III integral membrane proteins.