All categories

3 years ago

which of the following amino acids are used to measure the protein concentration by UV? A. His B. Pro C. Trp D. Phe E. Tyr

Chemistry

1 answer:

Goryan [66]3 years ago

7 0

Answer:

C. Trp D. Phe E. Tyr

Explanation:

The concentration of a protein has a direct relation with absorbance of the protein in a UV spectrophotometer. The formula which relates concentration with absorbance is described as under:

A = ∈ x c x l

where, A = Absorbance

∈ = Molar extinction co-efficient

c = Concentration of absorbing species i.e. protein

l = Path length of light

Tryptophan (Trp), phenylalanine (Phe ) and tyrosine (Tyr) are three aromatic amino acids which are used to measure protein concentration by UV. It is mainly because of tryptophan (Trp), protein absorbs at 280 nm which gives us an idea of protein concentration during UV spectroscopy.

The table depicting the wavelength at which these amino acids absorb and their respective molar extinction coefficient is as under:

Amino acid Wavelength Molar extinction co-efficient (∈)

Tryptophan 282 nm 5690

Tyrosine 274 nm 1280

Phenylalanine 257 nm 570

In view of table above, we can easily see that Molar extinction co-efficient (∈) of Tryptophan is highest amongst all these 3 amino acids that is why it dominates while measuring concentration.

You might be interested in

A cell using protein-mediated facilitated diffusion is treated with a toxin that prevents conformation change in the membrane pr

seraphim [82]

Answer:

The most likely outcome is that carrier protein dysfunction will increase the gradient which will lead to disruption of cellular metabolism.

3 0

3 years ago

4 On a bright, sunny day, which time of day can

Marina CMI [18]

It has to be J. 12:00am cause at night that’s when everything

5 0

3 years ago

A hot lump of 39.9 g of iron at an initial temperature of 78.1 °C is placed in 50.0 mL H 2 O initially at 25.0 °C and allowed to

Drupady [299]

Answer : The final temperature of the mixture is $29.6^oC$

Explanation :

In this problem we assumed that heat given by the hot body is equal to the heat taken by the cold body.

$q_1=-q_2$

$m_1\times c_1\times (T_f-T_1)=-m_2\times c_2\times (T_f-T_2)$

where,

$c_1$ = specific heat of iron = $0.499J/g^oC$

$c_2$ = specific heat of water = $4.18J/g^oC$

$m_1$ = mass of iron = 39.9 g

$m_2$ = mass of water = $Density\times Volume=1g/mL\times 50.0mL=50.0g$

$T_f$ = final temperature of mixture = ?

$T_1$ = initial temperature of iron = $78.1^oC$

$T_2$ = initial temperature of water = $25.0^oC$

Now put all the given values in the above formula, we get

$(39.9g)\times (0.499J/g^oC)\times (T_f-78.1)^oC=-(50.0g)\times 4.18J/g^oC\times (T_f-25.0)^oC$

$T_f=29.6^oC$

Therefore, the final temperature of the mixture is $29.6^oC$

8 0

3 years ago

Which equation represents the oxidation half-reaction for this redox reaction? Ca + Al(NO3)3 → Al + Ca(NO3)2

vodomira [7]

The oxidation half reaction of the reaction given above would be: Ca → Ca + 2e−. Oxidation is the loss of electrons of an element while its counterpart is called the reduction which gains the electrons that has been lost. Hope this answers the question.

5 0

3 years ago

Read 2 more answers

Suppose 110.0 mL110.0 mL of hydrogen gas at STP combines with a stoichiometric amount of fluorine gas and the resulting hydrogen

Fittoniya [83]

Suppose 110.0 mL of hydrogen gas at STP combines with a stoichiometric amount of fluorine gas and the resulting hydrogen fluoride dissolves in water to form 150.0 mL of an aqueous solution. 0.032 M is the concentration of the resulting hydrofluoric acid.

<h3>What is Balanced Chemical Equation ?</h3>

The balanced chemical equation is the equation in which the number of atoms on the reactant side is equal to the number of atoms on the product side in an equation.

Now write the balanced chemical equation

H₂ + F₂ → 2HF

<h3>What is Ideal Gas ?</h3>

An ideal gas is a gas that obey gas laws at all temperature and pressure conditions. It have velocity and mass but do not have volume. Ideal gas is also called perfect gas. Ideal gas is a hypothetical gas.

It is expressed as:

PV = nRT

where,

P = Pressure

V = Volume

n = number of moles

R = Ideal gas constant

T = temperature

Here,

P = 1 atm [At STP]

V = 110 ml = 0.11 L

T = 273 K [At STP]

R = 0.0821 [Ideal gas constant]

Now put the values in above expression

PV = nRT

1 atm × 0.11 L = n × 0.0821 L.atm/ K. mol × 273 K

$n = \frac{1\ \text{atm} \times 0.11\ L}{0.0821\ \text{L. atm/ K. mol} \times 273\ K}$

n = 0.0049 mol

<h3>How to find the concentration of resulting solution ? </h3>

To calculate the concentration of resulting solution use the expression

$C = \frac{n}{V}$

$= \frac{0.0049}{0.15}$

= 0.032 M

Thus from the above conclusion we can say that Suppose 110.0 mL of hydrogen gas at STP combines with a stoichiometric amount of fluorine gas and the resulting hydrogen fluoride dissolves in water to form 150.0 mL of an aqueous solution. 0.032 M is the concentration of the resulting hydrofluoric acid.

Learn more about the Ideal Gas here: brainly.com/question/25290815
#SPJ4

4 0

2 years ago