Hydrophobic Core

Definition

The hydrophobic core refers to the interior region of the cell membrane that is composed of nonpolar, lipid-soluble molecules. This core is the central, water-repelling layer of the membrane that acts as a barrier, preventing the passage of water-soluble substances across the membrane.

5 Must Know Facts For Your Next Test

1. The hydrophobic core of the cell membrane is composed primarily of the nonpolar, hydrocarbon tails of the phospholipid molecules.
2. The hydrophobic nature of the core prevents the passage of water-soluble substances, such as ions and polar molecules, across the membrane.
3. The hydrophobic core provides a barrier that helps maintain the cell's internal environment and regulates the movement of substances in and out of the cell.
4. The thickness and composition of the hydrophobic core can vary among different cell types and influence the membrane's permeability to specific molecules.
5. The hydrophobic core, along with the hydrophilic phospholipid heads, is essential for the overall structure and function of the cell membrane.

Review Questions

• Explain the role of the hydrophobic core in the structure and function of the cell membrane.
  • The hydrophobic core of the cell membrane is a crucial component that contributes to the membrane's structure and function. The core is composed of the nonpolar, lipid-soluble tails of the phospholipid molecules, which form a barrier that prevents the passage of water-soluble substances across the membrane. This hydrophobic region helps maintain the cell's internal environment, regulates the movement of molecules in and out of the cell, and is essential for the overall integrity and function of the cell membrane.
• Analyze how the properties of the hydrophobic core influence the permeability of the cell membrane.
  • The hydrophobic nature of the core region in the cell membrane directly affects its permeability to various substances. Molecules that are lipid-soluble, such as oxygen, carbon dioxide, and nonpolar drugs, can easily diffuse through the hydrophobic core. In contrast, water-soluble and polar molecules, like ions and glucose, are unable to freely pass through the hydrophobic barrier. This selective permeability is essential for maintaining the cell's internal environment and regulating the transport of necessary substances in and out of the cell. The thickness and composition of the hydrophobic core can also influence the membrane's overall permeability to specific molecules.
• Evaluate the importance of the hydrophobic core in the overall structure and function of the cell membrane.
  • The hydrophobic core is a critical component of the cell membrane that is essential for its structure and function. The nonpolar, lipid-soluble tails of the phospholipid molecules that make up the core create a hydrophobic barrier that prevents the passage of water-soluble substances across the membrane. This selective permeability helps maintain the cell's internal environment and regulates the transport of necessary molecules in and out of the cell. The hydrophobic core, along with the hydrophilic phospholipid heads, contributes to the overall integrity and stability of the cell membrane, allowing it to perform its vital roles in cellular processes, such as signaling, transport, and communication. Without the hydrophobic core, the cell membrane would not be able to effectively separate the internal and external environments, compromising the cell's ability to function properly.

Related terms

Phospholipid Bilayer: The phospholipid bilayer is the primary structural component of the cell membrane, consisting of two layers of phospholipid molecules arranged with their hydrophobic tails facing inward and their hydrophilic heads facing outward.

Lipid Solubility: Lipid solubility refers to the ability of a substance to dissolve in or be miscible with lipids, which are nonpolar molecules. Substances that are lipid-soluble can easily pass through the hydrophobic core of the cell membrane.

Membrane Permeability: Membrane permeability is the ease with which molecules can pass through the cell membrane. The hydrophobic core of the membrane acts as a barrier, allowing only lipid-soluble substances to freely diffuse across the membrane.