BioPHYSICAL chemistry

15.11 Amino acids forming proteins are only of one isomer; the other is

never present. In contrast, both isomers are often present when

inorganic molecules are synthesized.

15.12

15.13

15.14 Synchrotrons can generate very brilliant radiation at a range of

wavelengths.

15.15 In addition to making the density less pronounced compared to

the background level, the lack of data beyond a certain resolution

limit can artificially introduce negative density that can cancel true

density, as was found for nitrogenase.

15.16 Different answers are possible, such as the presence of a nonamino

acid residue, providing the opportunity for ligand coordinations that

are not possible with the restriction of amino acid residues.

15.17 The different conformations are associated with the electron

transfer and ATP hydrolysis steps, with the conformation leading

to a shortened distance for electron transfer and presumably a much

faster rate.

15.18 There is a single-bond distance associated with the cluster, pre-

sumably due to a single metal coordinated by a certain type of amino

acid; for example, a copper held in place by histidines.

CHAPTER 16

16.1 (a)

=2.13× 108 s−^1 =298 MHz

(b)

=8.51× 108 s−^1 =851 MHz

ν

γ

ππ

==(.× −−) ( )×

B

2

1

2

26 75 10^711 Ts 20 T

ν

γ

ππ

==(.× −−) ( )×

B

2

1

2

26 75 10^711 Ts 7 T

λ

()(. )

==.

×

− =×

9

8

9

842 11 10

225158

ZRh cm

10 −^9 cm=0 58. Å

ΔEZhcR

hc

=− h −

⎛

⎝

⎜⎜

⎞

⎠

(^222) ⎟⎟=

1

3

1

1 λ

λ

()(. )

==.

×

− =

9

8

9

829 11 10

2251122

ZRh cm

××= 10 −^8 cm 1 22. Å

ΔEZhcR

hc

=− h −

⎛

⎝

⎜⎜

⎞

⎠

(^222) ⎟⎟=

1

3

1

1 λ

476 ANSWERS TO PROBLEMS

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