Biological Membranes quiz Flashcards

The two main types of membrane proteins are integral membrane proteins and peripheral membrane proteins.

Integral membrane proteins are embedded within the cell membrane and usually span the entire phospholipid bilayer.

Peripheral membrane proteins are found on the periphery of the biological membrane and do not span the membrane like integral membrane proteins.

Peripheral membrane proteins can be located on either the extracellular side or the intracellular side of the biological membrane.

The phospholipid bilayer provides a medium through which integral membrane proteins can span and integrate into the cell membrane.

The intracellular portion faces the inside of the cell, while the extracellular portion faces the outside of the cell.

Peripheral membrane proteins interact with the cell membrane by attaching to its surface without embedding into the phospholipid bilayer.

The term 'integral' signifies that these proteins are integrated or embedded within the cell membrane.

Yes, peripheral membrane proteins can be found on both the extracellular and intracellular sides of the cell membrane.

Integral membrane proteins span the entire phospholipid bilayer, while peripheral membrane proteins are only attached to the surface of the membrane.

You would find an integral membrane protein spanning the entire biological membrane.

The extracellular portion of a peripheral membrane protein interacts with the external environment of the cell.

Integral membrane proteins contribute to the fluid mosaic model by being embedded within the phospholipid bilayer, adding to the dynamic and heterogeneous nature of the membrane.

The phospholipid bilayer forms the fundamental structure of the cell membrane, providing a fluid matrix in which proteins and other molecules can move and function.

The term 'peripheral' indicates that these proteins are located on the periphery or surface of the cell membrane, rather than being embedded within it.

The fluid mosaic model proposes that cellular membranes consist of protein molecules embedded in a dynamic bilayer of phospholipids.

The primary structural component is a phospholipid bilayer.

Proteins are embedded within the phospholipid bilayer.

The bilayer is described as dynamic, meaning it is fluid and constantly changing.

The term 'mosaic' is used because the membrane is composed of various proteins that float in or on the fluid lipid bilayer like tiles in a mosaic.

It is incorrect because cellular membranes are composed of a lipid bilayer, not a single layer.

Fatty acids are a component of the phospholipids that make up the bilayer.

The term 'dynamic' signifies that the bilayer is fluid and constantly in motion.

It is incorrect because there is no protein bilayer; the membrane consists of a lipid bilayer with proteins embedded within it.

The model suggests that proteins can move laterally within the lipid bilayer, contributing to the fluid nature of the membrane.

The model explains that the arrangement of proteins and lipids allows the membrane to selectively allow certain molecules to pass through while blocking others.

Cholesterol helps to stabilize the fluidity of the membrane by preventing the fatty acid chains of the phospholipids from sticking together.

The model accounts for this by suggesting that different proteins embedded in the lipid bilayer perform various functions such as transport, signaling, and structural support.

Active transport involves proteins in the membrane that use energy to move substances against their concentration gradient, a process facilitated by the dynamic nature of the membrane described in the fluid mosaic model.

The model suggests that membrane proteins play a crucial role in cell communication by acting as receptors for signaling molecules.