Use the Following Information When Answering the Corresponding Question(s)

question 55

Multiple Choice

Use the following information when answering the corresponding question(s) .
Rhodopsins are light-sensitive molecules composed of a protein (opsin) and retinal (derivative of vitamin A) . Opsin is a membrane protein with several α-helical segments that loop back and forth through the plasma membrane. There are two classes of rhodopsins. According to Oded Beje, one class has relatively slow dynamics (a photocycle of approximately 0.5 second) and is well suited for light detection. The second class has faster dynamics (a photocycle of approximately 0.02 seconds) and is well suited for chemiosmosis: pumping of protons or chloride ions across cell membranes. Oded Beje was the first, in September 2000, to report on a rhodopsin (proteorhodopsin) found in the domain Bacteria. [SOURCE: O. Beje et al., Science 289 (2000) : 1902.]
-For a protein to be an integral membrane protein, it would have to be ________.

• A) hydrophilic
• B) hydrophobic
• C) amphipathic, with at least one hydrophobic region
• D) completely covered with phospholipids
• E) exposed on only one surface of the membrane

---

Definitions:

Hostile

Exhibiting or characterized by antagonism, aggression, or a confrontational attitude towards others.

Abusive

Characterized by mistreatment or misuse of power, often resulting in harm or distress to others.

Moral System

A set of principles or values governing what individuals consider right and wrong behavior.

Sexual Morality

The moral and ethical considerations and standards related to sexual behavior and relationships.