Cell Membrane and Transport

Front

What is the structure of a phospholipid?

Back

A phospholipid consists of a hydrophilic (water-attracting) 'head' and two hydrophobic (water-repelling) 'tails'. This structure allows them to form bilayers in cell membranes.

Front

What does selectively permeable mean?

Back

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

Front

What role do proteins play in the cell membrane?

Back

Proteins in the cell membrane assist in transport, act as receptors for signaling, and provide structural support.

Front

What are glycoproteins?

Back

Glycoproteins are proteins that have carbohydrate chains attached to them, playing a key role in cell recognition and communication.

Front

What is passive transport?

Back

Passive transport is the movement of molecules across a cell membrane without the use of energy, typically along the concentration gradient.

Front

What is active transport?

Back

Active transport is the movement of molecules against their concentration gradient, requiring energy, often in the form of ATP.

Front

What is the function of cholesterol in the cell membrane?

Back

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

Front

What are the main components of the cell membrane?

Back

The main components of the cell membrane are phospholipids, proteins, carbohydrates, and cholesterol.

Front

What is endocytosis?

Back

Endocytosis is the process by which cells engulf substances from their external environment, bringing them into the cell.

Front

What is exocytosis?

Back

Exocytosis is the process by which cells expel materials, packaging them in vesicles that fuse with the cell membrane.