FiltersDone

Question type

Essay

Multiple Choice

Short Answer

True False

Matching

Exam 3: Protein Structure and Function

Show Answer

Share

---

All types

Filters

Study FlashcardsPractice ExamLearn

Question 1

Multiple Choice

Review LaterAdd Note

Review Later

You've just sequenced a new protein found in mice and observe that sulfur- containing cysteine residues occur at regular intervals. What is the significance of this finding?

A) It will be important to include cysteine in the diet of the mice.
B) Cysteine residues are involved in disulfide bridges that help form tertiary structure.
C) Cysteine causes bends, or angles, to occur in the tertiary structure of proteins.
D) Cysteine residues are required for the formation of a- helices and fi- pleated sheets.

Correct Answer

verified

Show Answer

Question 2

Multiple Choice

Review LaterAdd Note

Review Later

Which of the following statements about peptides is correct?

A) A peptide bond is formed by a condensation reaction between two carboxyl groups.
B) Joining two amino acids together through a peptide bond results in the formation of a carboxyl group.
C) As a whole, the structure of the peptide- bonded backbone is flexible.
D) A peptide bond is formed by a condensation reaction between the carboxyl and amino group of the same amino acid.
E) The peptide bond is capable of rotating.

Correct Answer

verified

Show Answer

Question 3

Multiple Choice

Review LaterAdd Note

An amino acid has an R- group that is positively charged at cellular pH. Which of the following categories would best describe it?

The aquaporin family of proteins plays a major role in the transport of water all over the body. During the folding process of these proteins, a- helices start forming as

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 structu proteins in order to understand what they do and how they do it. One of the most powerful techniques in existence today is X 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 a- 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?

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 structu proteins in order to understand what they do and how they do it. One of the most powerful techniques in existence today is X 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 a- 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.] -Refer to Figure 3.1. Which level of structure is being maintained by the disulfide bond?

Which one of the following is not a component of each monomer used to make proteins?

An enzyme has a total of four active sites. When you denature the molecule and study its composition, you find that each active site occurs on a different polypeptide. Which of the following hypotheses does this observation support?

At the pH found in cells about 7.0) , what happens to the carboxyl group on an amino acid?

You have isolated a previously unstudied protein, identified its complete structure in detail, and determined that it catalyzes the breakdown of a large substrate. You notice it has two binding sites. One of these is large, apparently the bonding site for the large substrate; the other is small, possibly a binding site for a regulatory molecule. What do these findings tell you about the mechanism of this protein?

If the primary structure of a protein is incorrect

Which of the following statements about the peptide- bonded backbone is correct?

Which of the following is not a major functional class of proteins?

An amino acid has an R- group that is negatively charged at cellular pH. Which of the following categories would best describe it?

Suppose you discovered a new amino acid. Its R- group contains only hydrogen and carbon atoms. Predict the behavior of this amino acid.

Which is not a role proteins play in organisms?

A peptide bond is

Consider the HIV enzyme called protease. The amino acid residues at the active site are highly hydrophobic. In designing a drug that would bind to the active site and jam it, researchers should use which type of molecule?

Which one of the following is not a component of each monomer used to make proteins?

You are studying a protein that is shaped like a doughnut. The shape is a function of which levels) of protein structure?