I have a test in spectroscopy and these are some practice guestions that were gi

Question

I have a test in spectroscopy and these are some practice guestions that were given.
Im not too confident in how to do them.
If someone could explain as they answered the question to help me understand that would be wonderful.

UV-VIS Spectroscopy A blood sample requires the determination of the amount of oxygenated haemoglobin. An aliquot of blood was diluted 1:1000 and measured in a spectrophotometer at 280nm. The Absorbance reading registered 1.2. Using a molar absorptivity coefficient of 131936 cm1/(moles/L), calculate the undiluted concentration of oxygenated haemoglobin in the blood sample. Peptide Mass Fingerprinting For the following protein: LLVFKAPDAWRMGEIGSIMRPSNQQDMRRILFEEHRWPYYHWGAKYCCCE Trypsin was used to create peptide fragments: LLVFK APDAWR MGEIGSIMRPSNQQDMR ILFEEHR WPYYHWGAK YCCCE Determine what the molecular masses are of the peptide fragments are and create a graphic depicting what the result would look like as a mass spectrum

Explanation / Answer

concentration of oxygenated blood can be calculated using the Beer-Lambart law,

A= epsilon x c x l------- (1)

where A= absorbance, epslon = molar absorvity coefficient(L/mol.cm) c= concentration of solute and l= length path which is generally 1cm

here they have given A=1.2 , epsilon = 131936 L/mol.cm and l= 1cm

so c=A/(epsilon x l) = 1.2 / 131936 = 9.1 x 10-6 mol/Ltr (this is the value of Blood in diluted condition)

as the dilution factor is 1000 ( since blood is diluted at the ratio of 1:1000)

so actual concentration of oxygenated blood in sample =9.1 x 10-6 x1000 = 9.1 x 10-3 mol/Ltr

2) The average molecular mass of an amino acid is 110Da

now fragment 1 has 5 amino acid therefore molecular mass of this fragment will be = 5x110 =550Da

fragment 2 has 6 amino acid therefore molecular mass of this fragment will be = 6x 110 = 660Da

fragment 3 has 17 amino acid therefore molecular mass of this fragment will be=17x 110 = 1870Da

fragment 4 has 1 amino acid therefore molecular mass of this fragment will be = 1x 110= 110Da

fragment 5 has 7 amino acid therefore molecular mass of this fragment will be = 7 x 110 = 770Da

fragment 6 has 9 amino acid therefore molecular mass of this fragment will be= 9 x 110 = 990Da

fragment 7 has 5 amino acid therefore molecular mass of this fragment will be= 5x 110=550Da

Related Questions

Navigate

• Browse (All)
• Browse I
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.