please answer all questions thank you point each MULTIPLE C

please answer all questions. thank you.

point each MULTIPLE C t. To measure 12 microuters en amoropcowe w o the foro wours you 2-20 dy 5 mL serological pipet chromatography, which of the folowing conNItues the mob we prwse? xchange 2. In gel futration Microscopic polymer beads Elution butter. 3 You wish to sept two proteins by chromahography, horse which protein do you e 7.000 (molecular a) horse myogol b) cow hemoglobin the same time c) both will elute a d) neither will elute

Solution

1. To measure 12 microlitres we use a 2-20 micropipette as 2-20 micropipette measures volumes of solution between 2-20 microliters and 12 microliters is within the range of the micropipette. So, the correct option is option C.

2. In gel filtration chromatography, the mobile phase is the elution buffer and the stationary phase is the small porous polymer beads that are designed to form pores of different sizes. So, the correct option is option D.

3. Proteins are separated by gel filtration chomatography based on their sizes. Any molecule with a larger size cannot enter the pores and so will be eluted with the buffer first. Small molecules, on the other hand will be retarded in the pores for a longer time and will be eluted at a later point. Since cow hemoglobin has a higher molecular weight compared to horse myoglobin, its size is relatively large compared to horse myoglobin and so it will be eluted first from the column. So, the correct option is option B.

4. Since 1 ml is equal to 1000 microliters, 1 ml is the same volume as 1000 microliters. So, the correct option is option D.

5. The statement, the isoelectric point is the pH at which there is a net charge on the molecule is false as isoelectric point is the pH at which the net charge on the molecule is zero ie., the positive charges on the molecule are equal to the negative charges on the molecule. At, this pH the molecule is neutral and doesnot move to either of the electrodes in isoelectric focussing separation of molecules. So, the correct option is option B.

6 and 7 questions cannot be answered as question 6 data is not clear and question 7 is also based on question 6 data.

8. Sickle cell anaemia is an autosomal recessive disorder. Since, one of the parent has both recessive genes and the other parent is heterozygous for the allele, the chances of offspring to inherit sickle cell anaemia is 50%.(according to the Punnett square diagram)

s

S

s

Ss

ss

s

sS

ss

S is a dominant allelle

s is a recessive allelle

9. Electrophoresis of hemoglobin from individuals with sickle cell trait shows to bands. It is because these individuals are carriers and they have both dominat and recessive form of the allele (Ss). In individuals with sickle cell anaemia trait there are different beta chains that form the asymmetric hybrid. As a result on electrophoresis we observe 2 different bands. So, the correct option is option C.

10. We will elute the remaining dye with 1.0M KOAc. Even after using 0.5M KOAc if the dye is not completely eluted, then we have to increase the concentration of KOAc to completely elute the sample. So, the correct option is option D.

Extra-credit

The beta globin subunit of normal hemoglobin has glutamic acid at position 6. However, in sickle cell anaemia glutamic acid is replaced by valine. This change in amino acid from glutamic acid to valine results in the formation of sickle hemoglobin. This sickle hemoglobin exists as an isolted unit when it is bound to oxygen. However, once the oxygen is released, the molecules stick together to form long chains of rigid polymers which look like the shape of a sickle under the microscope and thus the name sickle cell anaemia.

s	S	s
Ss	ss
s	sS	ss