Refer to the Following Paragraph and Figure 3

question 35

Multiple Choice

Refer to the following paragraph and Figure 3.1 to answer the following questions.

Figure 3.1
Since structure correlates so well with function,biochemists are constantly looking for new ways to probe the complex structure of proteins in order to understand what they do and how they do it.One of the most powerful techniques in existence today is X-ray crystallography.The main difficulty with this technique is getting the protein to crystallize.Once crystallized,the protein is bombarded with X-rays to create a pattern that can be analyzed mathematically to determine the three-dimensional structure of the protein.This analysis has been performed by Krzysztof Palczewski on the protein rhodopsin,which is a light-sensitive protein found in species ranging from ancient bacteria (archaea) to humans.The structure (schematically shown above,where each letter represents an amino acid) is characterized by a single polypeptide chain with several α-helical segments that loop back and forth across the cell membrane.Another notable feature is the disulfide bond (-S-S-) that can be seen at the bottom of the third transmembrane segment.[Figure adapted from K.Palczewski et al. ,Science 289 (2000) : 739.]
-If you were reading off the sequence of amino acids in Figure 3.1 to a biologist friend,what should the first three letters be?

• A)M-N-G
• B)A-P-A
• C)It doesn't matter,since the protein has no polarity or directionality.

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Definitions:

Pneumothorax

A medical condition where air or gas collects in the chest or pleural space, causing the lung to collapse.

Expiratory Crackles

Abnormal lung sounds heard during the end of the breathing cycle, suggestive of various conditions.

Absence of Breath Sounds

A condition where no sounds from breathing are heard upon auscultation, indicating potential respiratory distress or pathology.

Wheezes

High-pitched sounds produced during breathing, often indicating obstruction or narrowing of the airways.