Question

Name and briefly describe the three major classes of eukaryotic biological membranes.

Short answer

Answer: The three major classes of eukaryotic biological membranes are the plasma membrane, mitochondrial membranes, and the endomembrane system. The plasma membrane surrounds the cell, protects it, and controls the passage of substances in and out of the cell. Mitochondrial membranes are involved in energy production, with the outer membrane allowing the passage of small molecules and ions, and the inner membrane hosting the electron transport chain and ATP synthase. The endomembrane system consists of a network of interconnected membranes such as the nuclear envelope, endoplasmic reticulum, Golgi apparatus, and vesicles, which perform various functions including enclosing genetic material, protein synthesis and modification, lipid synthesis, and molecular transport.

Step-by-step solution

Name and describe the Plasma Membrane

The plasma membrane, also known as the cell membrane, surrounds the cell and acts as a barrier to protect the cell and maintain its structure. It's composed primarily of a phospholipid bilayer, with embedded proteins, cholesterol, and carbohydrates. The plasma membrane controls the passage of substances in and out of the cell, communicates with other cells, and receives signals from the environment.

Name and describe the Mitochondrial Membranes

Mitochondria are double-membrane-bound organelles, responsible for producing the majority of the cell's energy supply through the process of cellular respiration. The two mitochondrial membranes are called the outer mitochondrial membrane and the inner mitochondrial membrane. The outer mitochondrial membrane allows the passage of small molecules and ions, while the inner mitochondrial membrane hosts the electron transport chain and ATP synthase, which are crucial for energy production.

Name and describe the Endomembrane System

The endomembrane system consists of a network of interconnected membranes, which include the nuclear envelope, endoplasmic reticulum (ER), Golgi apparatus, and vesicles. The nuclear envelope encloses the cell's genetic material and separates it from the cytoplasm. The endoplasmic reticulum has two types - the rough ER, responsible for protein synthesis and modification, and smooth ER, which is involved in lipid synthesis and detoxification. The Golgi apparatus modifies, sorts, and packages proteins and lipids for transport to their final destinations. Vesicles transport and deliver molecules between different parts of the endomembrane system.