Replacement of a glutamate residue

The mutated form of hemoglobin (hemoglobin S, or HbS) in sickle-cell anemiaresults from the replacement of a glutamate residue by a valine residue at position 6 in the chain of the protein. (Normal hemoglobin is HbA.)

 

HbS has normal shape under normal conditions, but under conditions of low [O2] the hemoglobin forms fibrous aggregations, giving the entire red blood cell a sickle shape. Sickled red blood cells are relatively inflexible and may clog capillary beds, causing pain and tissue damage. The red blood cells also have a shorter life span, leading to anemia.

(a) Which of the following amino acids would you expect to produce a similar sickling effect if placed at position 6? Select all that apply.

1. Arginine

2. Leucine

3. Lysine

4. Alanine

5. Phenylalanine

(b) Sickling occurs in deoxyhemoglobin, but not in oxyhemoglobin. Normal deoxyhemoglobin (HbA and HbS) molecules have a small hydrophobic “pocket” on the surface of a ? chain. In oxyhemoglobin, however, this pocket is located toward the interior of the hemoglobin molecule. From what you know about the sickle-cell mutation and disease, determine which two amino acids make up this pocket.

1. Valine

2. Glutamate

3. Glutamine

4. Phenylalanine

5. Lysine

(c) How does aggregation occur in sickle-cell anemia? Place the steps in the correct order from no aggregation to sickle red blood cell. Note that deoxyhemoglobin is generally in the T state; oxyhemoglobin is in the R state.

AIDitional T state HbS interact with the growing aggregation to form an insoluble fiber.

Val interacts with the “pocket” of a beta chain on another HbS.

R state Hb shifts to T state Hb

O2 decreases due to vigorous exercise or high altitude.

Order a similar paper and get 15% discount. Use the coupon code GILB

Dr. Padma Myers
Dr. Padma Myers
98% Success Rate
Read More
“Hello, I deliver nursing papers on time following instructions from the client. My primary goal is customer satisfaction. Welcome for plagiarism free papers”
Stern Frea
Stern Frea
98% Success Rate
Read More
Hi! I am an English Language and Literature graduate; I have written many academic essays, including argumentative essays, research papers, and literary analysis.
Dr. Ishid Elsa
Dr. Ishid Elsa
98% Success Rate
Read More
"Hi, count on me to deliver quality papers that meet your expectations. I write well researched papers in the fields of nursing and medicine".
Dr. Paul P. Klug
Dr. Paul P. Klug
99% Success Rate
Read More
"A top writer with proven reliability and experience. I have a 99% success rate, overall rating of 10. Hire me for quality custom written nursing papers. Thank you"

How Our Essay Writing Service Works

Tell Us Your Requirements

Fill out order details and instructions, then upload any files or additional materials if needed. Then, confirm your order by clicking “Place an Order.”

Make your payment

Your payment is processed by a secure system. We accept Mastercard, Visa, Amex, and Discover. We don’t share any informati.on with third parties

The Writing Process

You can communicate with your writer. Clarify or track order with our customer support team. Upload all the necessary files for the writer to use.

Download your paper

Check your paper on your client profile. If it meets your requirements, approve and download. If any changes are needed, request a revision to be done.

Recent Questions

Stay In Touch!

Leave your email and get discount promo codes and the best essay samples from our writers!