Cell Membrane Structure

Front

What is the structure of the phospholipid bilayer in the cell membrane?

Back

The phospholipid bilayer consists of hydrophilic (water-attracting) heads facing outward towards the water inside and outside the cell, and hydrophobic (water-repelling) tails facing inward, away from the water.

Front

What is the role of cholesterol in the cell membrane?

Back

Cholesterol helps to stabilize the cell membrane's fluidity and structure, making it less permeable to very small water-soluble molecules that might otherwise pass freely through.

Front

What are the main functions of proteins in the cell membrane?

Back

Proteins in the cell membrane function as transporters for ions and molecules, serve as signal receptors, and can provide structural support.

Front

What does the term 'selectively permeable' mean in relation to the cell membrane?

Back

Selectively permeable means that the cell membrane allows certain substances to pass through while blocking others, maintaining the internal environment of the cell.

Front

What is the difference between hydrophilic and hydrophobic molecules?

Back

Hydrophilic molecules are attracted to water (e.g., sugars), while hydrophobic molecules repel water (e.g., oils).

Front

How do small nonpolar molecules pass through the cell membrane?

Back

Small nonpolar molecules can easily pass through the phospholipid bilayer due to their compatibility with the hydrophobic interior of the membrane.

Front

What is the function of glycoproteins in the cell membrane?

Back

Glycoproteins serve as recognition sites for cell signaling and communication, helping cells identify each other.

Front

What is the significance of the fluid mosaic model of the cell membrane?

Back

The fluid mosaic model describes the cell membrane as a dynamic structure with various proteins floating in or on the fluid lipid bilayer, allowing for flexibility and movement.

Front

What is the role of transport proteins in the cell membrane?

Back

Transport proteins facilitate the movement of substances across the cell membrane, including ions and larger molecules that cannot pass through the lipid bilayer directly.

Front

What does it mean for a molecule to be amphipathic?

Back

An amphipathic molecule has both hydrophilic (water-attracting) and hydrophobic (water-repelling) parts, like phospholipids in the cell membrane.