In what way do the membranes of a eukaryotic cell vary? a. Phospholipids are found only in certain membranes. b. Certain proteins are unique to each membrane. c. Only certain membranes of the cell are selectively permeable. d. Only certain membranes are constructed from amphipathic molecules.

Key Concepts

Eukaryotic Cell Membranes

Eukaryotic cells have complex membranes that serve as barriers and facilitators for cellular processes. These membranes are primarily composed of a phospholipid bilayer, which provides fluidity and flexibility, allowing for the compartmentalization of cellular functions. Each membrane can have distinct compositions and functions, reflecting the specific roles of the organelles they enclose.

Membrane Proteins

Membrane proteins are integral or peripheral proteins that perform various functions, including transport, signaling, and structural support. Different membranes can contain unique sets of proteins, which contribute to the specific functions of each membrane. For example, the proteins in the plasma membrane differ from those in the endoplasmic reticulum, reflecting their distinct roles in the cell.

Selective Permeability

Selective permeability refers to the ability of a membrane to allow certain substances to pass while blocking others. This property is crucial for maintaining homeostasis within the cell, as it regulates the entry and exit of ions, nutrients, and waste products. Not all membranes exhibit the same level of selective permeability, which can vary based on their composition and the presence of specific transport proteins.