BioPHYSICAL chemistry

CHAPTER 14

14.1 A=εcl

where the proportionality constant εis the molar absorption co-

efficient, or extinction coefficient, the concentration of the absorber

is c, the pathlength of the sample is l, the intensity of the incident

light is I, and the intensity of the exiting light is I 0.

14.2 (a)

(b)

(c)

14.3 (a)

(b)

(c)

14.4 (a)A=0.27

(b)

14.5 (a)A=0.0154

(b)

14.6

14.7 (a)A=cεl=(1 × 10 −^6 M)(1 × 104 M−^1 cm−^1 )(1 cm) =0.01

(b)A=cεl=(2 × 10 −^4 M)(1 × 104 M−^1 cm−^1 )(1 cm) = 2

14.8

14.9 w′=B′ρ

[]

(, )(. ) ( )(.

Trp =

11 300MM−−^11 0 239 − 1500 0 71 77

11 300 5380 1500 1960

112

)

( , )( ) ( )( )

.

MM−−−

= 8 81 10× −^5 M

[]

()(.)()(.)

Tyr =

5380 MM−−^11 0 717 − 1960 0 239

(( , )( ) ( )( )

.

11 300 5380 1500 1960

11585

MM−−−

=× 10 −^5 M

c

A

l

==.

×

=

−

ε −−

10

10 1

01

1

31 1Mcm cm mM

c

A

l (. )( )

==.

×

=

−

ε −−

10

154 10 1

6

1

41 1Mcm cm^551065

×=−^6 MM. μ

c

.

=× =.%. %

1

27

01 0037

λ

ν

==

×

×

=×

−

−

c (^310) −
110

310

81

12 1

ms 4

s

m→infrared

λ

ν

==

×

×

=× →

−

−

c 310

110

310

81

61

ms 2

s

mrradiowave

λ

ν

==

×

×

=×

−

−

c (^310) −
110

310

81

18 1

ms 10

s

mm→X-ray

ν

λ

==.

×

×

=×

−

−

c 310

310

10 10

81

2

ms 10

m

m→microwave

ν

λ

==.

×

×

=×

−

−

c 310

510

60 10

81

7

ms 14

m

m→→visible

ν

λ

==

×

×

=× →

−

−

c 310

110

310

81

9

ms 17

m

m X-ray

ANSWERS TO PROBLEMS 473

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