The plasma membrane is referred to as a "fluid mosaic" structure. Which of the following statements about that model is true?

• A. The fluid aspect of the membrane is due to the behavior of phospholipids, and the mosaic aspect is due to the presence of carbohydrates.
• B. The fluid aspect of the membrane describes its structure at normal temperatures, and the mosaic aspect describes the behavior of the membrane as the temperature is lowered.
• C. The mosaic aspect of the membrane is due to the glycosylation of phospholipids on the cytoplasmic side of the membrane.
• D. Only phospholipids are capable of moving in the membrane.
• E. The fluid aspect of the membrane is due to the mobility of phospholipids, and embedded proteins account for the mosaic aspect.

Answer: (E)

Verified step by step guidance

1. Understand the 'fluid mosaic model': This model describes the structure of cell membranes. It suggests that the membrane is flexible (fluid) and composed of various molecules like proteins and lipids (mosaic).
2. Identify the components of the membrane: The primary components are phospholipids, proteins, and carbohydrates. Phospholipids form a bilayer, providing fluidity, while proteins are interspersed throughout, creating a mosaic pattern.
3. Analyze the fluid aspect: Phospholipids in the bilayer can move laterally, allowing the membrane to be flexible and dynamic. This lateral movement is what gives the membrane its fluid characteristic.
4. Examine the mosaic aspect: The proteins embedded within the phospholipid bilayer vary in size, shape, and function, contributing to the 'mosaic' appearance. These proteins can be integral or peripheral, playing roles in transport, signaling, and structural support.
5. Evaluate the given statements: The correct statement should reflect the fluid nature due to phospholipid mobility and the mosaic nature due to the presence of proteins. The correct answer is: 'The fluid aspect of the membrane is due to the mobility of phospholipids, and embedded proteins account for the mosaic aspect.'