Membrane Structure and Function: Matching Terms to Statements

Q1. For each term (Integral membrane proteins and Lipids), select ALL statements that apply from the provided list. Only glucose metabolism is considered when answering.

Background

Topic: Cell Membrane Structure and Function

This question tests your understanding of the structure and roles of integral membrane proteins and lipids in the plasma membrane, especially in the context of glucose metabolism. It also examines your ability to distinguish between the properties and functions of these two major membrane components.

Key Terms and Concepts

• Integral membrane proteins: Proteins that are permanently embedded within the plasma membrane, often spanning the bilayer. They play roles in transport, signaling, and cell recognition.

• Lipids: The main structural components of membranes, including phospholipids, glycolipids, sterols (cholesterol, ergosterol), and others. They form the bilayer and contribute to membrane fluidity and function.

• Plasma membrane: The lipid bilayer that encloses the cell, containing both proteins and lipids.

• FRAP (Fluorescence Recovery After Photobleaching): A technique to study lateral movement of membrane components.

• Flippases: Enzymes that catalyze the flip-flop movement of lipids between membrane leaflets.

• Passive/Active Transport: Mechanisms by which substances move across membranes, often involving proteins.

Step-by-Step Guidance

1. Read each statement (A–X) carefully and consider whether it describes a property or function of integral membrane proteins, lipids, or both. Focus on the context of the plasma membrane and glucose metabolism.

2. For integral membrane proteins, look for statements that mention protein-specific features, such as spanning the membrane, acting as transporters, being involved in active or passive transport, or being isolated by protein-specific techniques (e.g., SDS-PAGE).

3. For lipids, identify statements that refer to the bilayer structure, hydrophobic tails, fluidity, and types of lipids (phospholipids, glycolipids, sterols). Also, consider statements about movement within the membrane (lateral diffusion, flip-flop) and their role in membrane asymmetry.

4. Remember that some statements may apply to both terms, one, or neither. For example, both proteins and lipids can be found in the plasma membrane, but only proteins can act as transporters for glucose or ions.

5. Write down the letters of all statements that apply to each term. Double-check your choices by reviewing the definitions and functions of each component in the context of the plasma membrane and glucose metabolism.

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