Question

11.Which of the following mutations would most likely to disrupt the structure of an α-helix?

1. Cys to Ala
2. Lys to Arg
3. Glu to Gly
4. Val to Leu

12.Which amino acid combination is the most preferred to occupy positions 1 and 4 in an α-helix?

1. Glu and Lys
2. Phe and Pro
3. Lys and Arg
4. Asp and Glu

13.If each turn in the standard alpha helix extends 5.4 A and there are 3.6 amino acid residues per turn, how many amino acids are there in an alpha helix that measures 72 A?

1. 6
2. 12
3. 24
4. 48

14.Which of the following fibrous proteins is not found in connective tissues?

1. Collagen
2. Keratin
3. Elastic
4. Actin

15.The phi and psi angles in small peptide have been determined and shown below. What type of protein is this

peptide?

1. Collagen
2. Keratin
3. Elastin
4. Actin

16.Which of the following amino acids is the most likely to be buried within an aqueous protein?

1. ILe
2. Arg
3. Ser
4. His

17.Which of the following substitution mutations in a protein is the most likely to cause the protein to lose its function?

1. Leu to ILe
2. Arg to Lys
3. Val to Ala
4. Asp to Lys

18.Which of the following is correct about prion disease?

1. the pathogen is a virus that resists extreme heat
2. the pathogen is a fungus that specifically attacks the nervous system
3. a lysine-glycine substitution is responsible for the signaling dysfunction
4. the amyloid plaques are dominantly beta sheets

19.Which of the following denaturing factor alters the surface changes on a protein?

1. pH
2. Heat
3. Detergent
4. Heavy metal

20.As we explained in class, DNA molecules are elastic and tend to resist bending. in eukaryotic cells, however, DNA is wrapped around a protein spindle made of a special kind of protein called histones. which of the following amino acids do you expect to appear frequently on the surface of the histones?

1. Asp and Glu
2. Ser and Thr
3. Phe and Leu
4. Arg and Lys

Answer 1

11. Glu to Gly mutations would most likely to disrupt the structure of an α-helix.

12. Glu and Lys amino acid combination is the most preferred to occupy positions 1 and 4 in an α-helix.

13. 12 are there in an alpha helix that measures 72 A.

14. Collagen fibrous proteins is not found in connective tissues.

15. Collagen.

16. Ser amino acids is the most likely to be buried within an aqueous protein becaus eit is poalr and can form H bonds with water molecule.

17. Asp to Lys substitution mutations in a protein is the most likely to cause the protein to lose its function.

18. the amyloid plaques are dominantly beta sheets.

19. Detergent alters the surface changes on a protein.

20. Arg and Lys because they are +ve charged