Select one bolded section that interests you and read through it. Summarize what the rules cover. Is there anything missing that you feel should be added? Are there any guidelines that you would eliminate? What would be the biggest challenge an auditor might face following your chosen section? Be sure to respond to at least one of your classmates’ posts with new information about the topic, a clarifying example, and so on.
The Correct Answer and Explanation is:
(a) Where might bends or β turns occur?
Bends or β turns often occur in protein sequences where:
- There is a need for a directional change in the polypeptide chain.
- Amino acids with small or flexible side chains like glycine (Gly) or proline (Pro) are present.
Common locations for β turns:
- Near glycine due to its small size and flexibility.
- Near proline due to its rigid cyclic structure which introduces a kink.
- In polar or charged residues (e.g., Ser, Asp, Asn), often found on the protein surface and involved in tight turns.
So, look for regions with Gly, Pro, Ser, Asn, Asp, or similar residues in the sequence to predict where bends or β turns might occur.
(b) Where might intrachain disulfide cross-linkages be formed?
Intrachain disulfide bonds are covalent bonds formed between two cysteine (Cys) residues within the same polypeptide chain. These bonds help stabilize the tertiary structure.
- Check for Cys residues in the sequence.
- If two Cys residues are relatively close (but not adjacent) in the sequence or structure, they may form a disulfide bridge.
- Disulfide bonds are more likely to occur in oxidizing environments, such as the extracellular environment.
(c) Probable location of amino acid residues in a globular protein:
| Residue | Likely Location | Reasoning |
|---|---|---|
| Asp | External surface | Charged (acidic); hydrophilic; interacts with water. |
| Ile | Interior | Nonpolar, hydrophobic; buried to avoid water. |
| Thr | External or near surface | Polar but uncharged; can form H-bonds with water; often on surface or intermediate. |
| Ala | Interior | Small, nonpolar; commonly found in the hydrophobic core. |
| Gln | Surface or intermediate | Polar side chain (amide group); forms H-bonds; usually on or near surface. |
| Lys | External surface | Positively charged; hydrophilic; interacts with water or acidic residues. |
Second Part: Auditing Rules Reflection
You were also asked to:
- Choose a section of auditing rules (likely from your course materials),
- Summarize, critique, and discuss challenges of implementation,
- And respond to a peer’s post.
Let’s walk through how you might structure that response:
Sample Summary (if you chose “Independence and Objectivity”):
The section on Independence and Objectivity emphasizes that auditors must remain free of conflicts of interest, both in fact and appearance. It outlines prohibitions against financial interests in audit clients, restrictions on providing certain non-audit services, and requirements for rotation of audit partners to prevent familiarity threats.
What’s Missing or Should Be Added?
While the rules cover many financial relationships, there’s less emphasis on non-financial conflicts (e.g., personal friendships, family ties). Additional guidance on social media conduct or remote audit relationships could strengthen the rules.
Guidelines You Might Eliminate?
The rule limiting all non-audit services could be refined instead of blanket prohibitions. If appropriate safeguards exist, some advisory roles might not impair independence.
Biggest Challenge for Auditors:
The greatest challenge is maintaining objectivity when close relationships exist, especially in smaller firms or repeat engagements where familiarity is hard to avoid.
Sample Peer Reply:
Hi [Name], great point about partner rotation. One example where this really matters is in long-term government audits where institutional memory is valuable. How do you think we can balance continuity with independence? Maybe a secondary reviewer role could help?
If you can specify the protein sequence or the section of auditing rules you’re reviewing, I can tailor these responses even more precisely!
