Can you please help me with these questions and explain how

Can you please help me with these questions and explain how to read a gel electrophoresis pattern and restriction maps, thank you

5. The agarose gel at the right shows the pattern of bands obtained when a particular fragment of double- stranded DNA is digested to completion with the restriction enzymes shown a. Which of the six restriction maps shown below is consistent with the observed pattern of restriction fragments? 10 12 kb LT 1 10 12 kb A N 10 12 kb 0.5 N A E-ELOR 10 12 kb A N 10 2 kb E A N N A E 8 kb

Solution

Explanation of how to read a gel electrophoresis pattern and restriction maps:

We have 6 restriction maps:

1. restriction map: (of 12 kb fragment size)

If we use E restriction enzyme: We can cleave the given DNA into 3 fragments one is 6 KB and other is 5 kb and the other is 1 kb. So it cleaves at 6 kb and 11 kb site

If we use A restriction enzyme: We can cleave the given DNA into 2 fragments one is 8 KB and other is 4 kb so it cleaves at 8 kb site

If we use N restriction enzyme: We can cleave the given DNA into 2 fragments one is 3 KB and other is 9 kb. so it cleaves at 3 kb site

Similarly do for all, presenting simply in table format

Restriction map in order from top to bottom

Length Kb

E restriction enzyme

A restriction enzyme

N restriction enzyme

Cleaves at

Fragments size

Cleaves at

Fragments size

Cleaves at

Fragments size

1

12

6kb

11 kb

6 kb

5kb

1 kb

8kb

8 kb

4 kb

3 kb

3 kb

9 kb

2

12

6 kb

11 kb

6 kb

5 kb

1 kb

3 kb

3 kb

9 kb

8 kb

8 kb

4 kb

3

12

6 kb

11 kb

6 kb

5 kb

1 kb

8kb

8 kb

4 kb

9 kb

9 kb

3 Kb

4

12

6 kb

11 kb

6 kb

5 kb

1 kb

4 kb

4 kb

8 Kb

3 kb

3 kb

9 kb

5

12

6 kb

11 kb

6 kb

5 kb

1 kb

3 kb

3kb

9 kb

4 kb

4 kb

8Kb

6

8

1 kb

6 kb

1 kb

5 kb

2 kb

2 kb

5 kb

2 kb

3 Kb

3 Kb

3 kb

4 kb

3 kb

1 kb

4 kb

Gel electrophoresis:

Agarose gel shows us 5 wells (1st well with A restriction enzyme. 2 well with N restriction enzyme, 3rd well with A+N restriction enzyme, 4rth well with E restriction enzyme and 5th well with restriction enzyme).

And on the Y axis we can see the Fragment size in Kb. This shows the  size of the fragments formed after restriction.

We will study all the wells:

Well

Restriction enzyme

A

N

A+N

E

E+N

cleaves the DNA at

Fragments formed

cleaves the DNA at

Fragments formed

cleaves the DNA at

Fragments formed

cleaves the DNA at

Fragments formed

cleaves the DNA at

Fragments formed

1

2 sites

3 kb

9 kb

2

2 sites

4 kb

8 kb

3

3 sites

1 Kb

3 kb

8 kb

4

3 sites

1 Kb

5 kb

6 kb

5

4 sites

1 kb

2 kb

4 kb

5 kb

5.

a. Which of the six restriction maps shown below is consistent with the observed pattern of restriction fragments?

Ans: Thus clearly shows it restriction map 5 is consistent with the observed pattern of restriction fragments. We can come to conclusion after checking all the fragments formed which are clearly shown in both the tables as bolded.

B. Where is the pep gene located in the correct restriction map?

Ans:, Examining all those locations of pep gene in the restriction map 5, Pep must be in between 3 -4 kb fragment size positions

Fragment 5: ........................A3 kb.......N 4kb..................E.............................E

Take well 1 which gives us 9 Kb fragment with A, which shows (12kb= 3+9kb) the gene should be at 2nd fragment side.

2 Well we can see 4 kb length fragment with N, which shows (12kb= 4kb+8 kb) the gene should be at 1st fragment side.

From this we can say our required  pep gene in the restriction map 5 is in between 3 to 4 kb length

Further 3rd wll, A+N digestion gives us 1 kb (3to 4 kb region). so this confirms our PEP is a 1kb length fragment between 3-4 kb length

Well

Restriction enzyme

A

N

A+N

E

E+N

Fragments formed

Fragments formed

Fragments formed

Fragments formed

Fragments formed

1

9 kb

2

4 kb

3

1 kb

4

6 kb

5

4 kb

Restriction map in order from top to bottom	Length Kb	E restriction enzyme	A restriction enzyme	N restriction enzyme
Cleaves at	Fragments size	Cleaves at	Fragments size	Cleaves at	Fragments size
1	12	6kb 11 kb	6 kb 5kb 1 kb	8kb	8 kb 4 kb	3 kb	3 kb 9 kb
2	12	6 kb 11 kb	6 kb 5 kb 1 kb	3 kb	3 kb 9 kb	8 kb	8 kb 4 kb
3	12	6 kb 11 kb	6 kb 5 kb 1 kb	8kb	8 kb 4 kb	9 kb	9 kb 3 Kb
4	12	6 kb 11 kb	6 kb 5 kb 1 kb	4 kb	4 kb 8 Kb	3 kb	3 kb 9 kb
5	12	6 kb 11 kb	6 kb 5 kb 1 kb	3 kb	3kb 9 kb	4 kb	4 kb 8Kb
6	8	1 kb 6 kb	1 kb 5 kb 2 kb	2 kb 5 kb	2 kb 3 Kb 3 Kb	3 kb 4 kb	3 kb 1 kb 4 kb