Optometry Admission Test (OAT) Practice

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Study for the Optometry Admission Test (OAT). Dive into multiple choice questions, each with explanations and helpful hints. Enhance your knowledge and prepare for success in your exam!

Each practice test/flash card set has 50 randomly selected questions from a bank of over 500. You'll get a new set of questions each time!

Practice this question and more.

Where is the phospholipid head located?

In the fatty-acid region
In the phosphoric-acid region
In the protein region
In the cholesterol region

The correct answer is: In the phosphoric-acid region

The phospholipid head is indeed located in the phosphoric-acid region. Phospholipids consist of a glycerol backbone, two fatty acid tails, and a phosphate group that is attached to an organic molecule, such as choline or serine. The phosphate group and any associated groups constitute the hydrophilic, or "water-attracting," portion of the molecule, forming the phospholipid head. This head is polar and interacts well with aqueous environments, facilitating the formation of cellular membranes where the phospholipid bilayer serves as a barrier to the passage of substances. In the context of cellular membranes, the significance of the phospholipid head is that it allows the membrane to be fluid and flexible while maintaining its structural integrity. This characteristic is crucial for cellular processes such as signaling and transport. Therefore, understanding the position and function of the phospholipid head provides essential insight into cellular biology and membrane dynamics.