Gress.

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

Goryan [66]

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.

7 0

3 years ago

One lap of an engineered hamster track measures 255 cm. To run 10. meters, how many laps should the hamster run? Report your ans

Maru [420]

Answer:

3.9 laps

Explanation:

Step 1: Given data

Length of the hamster track (L): 255 cm

Total distance to be run (D): 10 m

Step 2: Convert "D" to centimeters

We will use the relationship 1 m = 100 cm.

10 m × (100 cm/1 m) = 1.0 × 10³ cm

Step 3: Calculate the number of laps (n) that the hamster should run

We will use the following expression.

n = D/L

n = 1.0 × 10³ cm/255 cm

n = 3.9

4 0

3 years ago

Valence electrons<br> Fill in the blanks

IgorC [24]

Answer:

Valence electrons or outer electrons are most important as they participate in bonding. The octet rule states that atoms gain, lose, or share valence electrons to have filled energy levels.. this gives atoms a stable configuration like that of the nearest noble gas.

6 0

3 years ago

Which element forms more compounds than all the other elements combined?

katen-ka-za [31]

The Element that form more compounds than all the rest is Carbon.

Elements of Carbon
<span>A molecule of the compound carbon dioxide contains one atom of the element carbon and two atoms of the element oxygen. Each oxygen atom shares a double bond with the carbon atom. Carbon is the sixth element in the periodic table and occurs in pure form as coal and diamonds.

Hopefully I helped ^.^ Mark brainly if possible~
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5 0

4 years ago

A scientist wants to make a solution of tribasic sodium phosphate, Na3PO4, for a laboratory experiment. How many grams of Na3PO4

Anna71 [15]

Answer:

31.652g of Na3PO4

Explanation:

We'll begin by calculating the molarity of Na3PO4 solution. This can be achieved as shown below:

Na3PO4 will dessicate in solution as follow:

Na3PO4(aq) —> 3Na+(aq) + PO4³¯(aq)

From the balanced equation above,

1 mole of Na3PO4 produce 3 moles of sodium ion, Na+.

Therefore, xM Na3PO4 will produce 1.10M sodium ion, Na+ i.e

xM Na3PO4 = (1.10 x 1)/3

xM Na3PO4 = 0.367M

Therefore, the molarity of Na3PO4 is 0.367M.

Next, we shall determine the number of mole of Na3PO4 in the solution. This is illustrated below:

Molarity of Na3PO4 = 0.367M

Volume = 525mL = 525/1000 = 0.525L

Mole of Na3PO4 =..?

Molarity = mole /Volume

0.367 = mole /0.525

Cross multiply

Mole of Na3PO4 = 0.367 x 0.525

Mole of Na3PO4 = 0.193 mole.

Finally, we shall convert 0.193 mole of Na3PO4 to grams. This is illustrated below:

Molar mass of Na3PO4 = (23x3) + 31 + (16x4) = 164g/mol

Mole of Na3PO4 = 0.193 mole

Mass of Na3PO4 =.?

Mass = mole x molar mass

Mass of Na3PO4 = 0.193 x 164

Mass of Na3PO4 = 31.652g

Therefore, 31.652g of Na3PO4 is needed to prepare the solution.

6 0

3 years ago