ANATOMY AND PHYSIOLOGY OF CELL: STRUCTURE, FUNCTION & TRANSPORT SYSTEM OF THE CELL MEMBRANE

This flashcard set covers key concepts relating to the anatomy and physiology of cellular membranes, including their structure, function, transport mechanisms, and cellular junctions.

What is the primary function of the plasma membrane?

The plasma membrane serves as a mechanical barrier and selectively controls the movement of molecules between the extracellular fluid and intracellular fluid.

What are the main lipids found in the plasma membrane?

Phospholipids, glycolipids, and cholesterol.

What distinguishes intrinsic membrane proteins from extrinsic membrane proteins?

Intrinsic proteins span the entire membrane, while extrinsic proteins are located on the periphery of the membrane.

What are the two types of active transport?

Primary Active Transport and Secondary Active Transport.

What is the role of glycoproteins in the plasma membrane?

Glycoproteins serve as cell identity markers and are involved in cell recognition.

Describe the process of osmosis.

Osmosis is the diffusion of water across the plasma membrane down its concentration gradient.

What is a tight junction?

A tight junction is a barrier formed by integral membrane proteins that prevents substances from passing between cells.

What occurs during facilitated diffusion?

Facilitated diffusion involves transport proteins aiding the movement of substances across the membrane without energy input.

How do passive transport and active transport differ?

Passive transport occurs down a concentration gradient without energy, while active transport requires energy to move substances against a concentration gradient.

What is the function of desmosomes?

Desmosomes provide mechanical stability and strength to tissues subject to stress.

What is the significance of membrane fluidity?

Membrane fluidity allows for the movement and flexibility of the membrane, enabling cells to change shape without losing structural integrity.

What role do membrane proteins play in enzymatic activity?

Membrane proteins can act as enzymes with active sites exposed to substances in the adjacent solution.

Define the term 'selective permeability' as it relates to the plasma membrane.

Selective permeability refers to the ability of the plasma membrane to allow certain substances to pass through while restricting others.

What happens during primary active transport?

In primary active transport, substances are 'pumped' against their concentration gradient using energy from ATP hydrolysis.

Describe gap junctions and their function.

Gap junctions are channels that allow ions and small molecules to pass directly between adjacent cells, providing a direct electrical connection.

What is the function of cholesterol in the plasma membrane?

Cholesterol increases membrane flexibility and stability and helps to increase the hydrophobicity of the membrane.

How do carrier proteins function in the membrane transport?

Carrier proteins bind to specific molecules and undergo conformational changes to transport the substance across the membrane.