Answer the following clearly For points For multiple choice, explain why you pic
ID: 820768 • Letter: A
Question
Answer the following clearly For points
For multiple choice, explain why you pick that answer
1.What is the maximum number of hydrogen bonds that one water molecules can have with neighboring water molecules?
A. 1
B. 2
C. 3
D. 4
2.The last common ancestor of modern organisms must have used
A. L amino acids
B. D amino acids
C. Both
D either D or L
3. UV light can be used to estimate protein solution concentration because
A. Phenylalanine absorbs at 260nm
B. Tryptophan and tyrosine absorbs at 280nm
C. Aromatic amino acids abosrbs at 280nm.
D. All amino acids obsorbs UV light
E. all of above
4. The peptide bond is which of the following?
A. an ester bond
B. amine bond
C. amide bond
D. ether bond
5. Proline is not often found in a helices of protein because it
A. has a very bulky side chain,
B. interacts with adjacent amino acids.
C. lacks hydrogen atom on its amide nitrogen
D. has a small, uncharged side chain.
Short answer repsonses
6. Water clustered about non polar molecules contribute to hydrophobic interacts because?
7. The pka of tyrosines are 2.2, 9,1, and side chain is 10.1. calculate PI for tyr.
8.Glycine has a carboxyl group pka of 2.3 and an amide group pka of 9.6. For which ranges could glycine function as a buffer?
9. Chymotrypsin cleaves after aromatic residues. write the products that would result from chymotrypsin cleaves of the following unlikely peptide
ADEFGHIKLMNPQRSTVWY
10. Explain the molecular basis of sickle cell anemia?
Explanation / Answer
10. Explain the molecular basis of sickle cell anemia?
Sickle cell anemia is a disease of the erythrocytes caused by an autosomal recessive single gene defect in the ?-globin chain of adult hemoglobin (HbA) that produces a mutant form of hemoglobin known as sickle hemoglobin (HbS)
Sickle cell anemia occurs if HbS is inherited from both parents (HbSS genotype). Other forms of sickle cell disease may occur if HbS is inherited from one parent and another abnormal hemoglobin, such as hemoglobin C (HbC), or ?-thalassemia is inherited from the other parent (resulting in HbSC or HbS?-thalassemia genotype, respectively)
The term sickle cell anemia refers to HbSS disease, whereas the term sickle cell disease refers to all of the genotypes
HbS confers abnormal properties to erythrocytes; the cells break apart easily, and their characteristic crescent shape can disrupt blood flow
HbS is associated with varying degrees of anemia; a predisposition to obstruction of small blood capillaries, causing painful (vaso-occlusive) crises; damage to major organs; and increased vulnerability to severe infections