4A-enzymes that manipulate DNA

Question 1

restriction enzymes/ restirction endonucleases

Answer 1

restriction enzymes cut DNA into smaller fragments in order to isolate the gene of interest.

Question 2

circular DNA produces 1 less fragemnet then cut double check than linear dna eg. circular dna 3 cuts= 3 frgaemets but linear dna 3 cuts is 4 fragements

Question 3

There are 100 base pairs in a DNA strand, 20 are A and 20 are T, how mamny are C and G.

Answer 3

NOTE if theres 100 base pairs that meanstheres 200 nulcoeitide,s which means that A=20, T=20 andwhats left ove ris 80 and 80 so
C=80 and G=80

Question 4

recognition site

Answer 4

specific target sequence of the DNA that restriction enzyme cuts

Question 5

what kind of bonds between nucleic acids

Answer 5

phosphodiester bond

Question 6

restriction endonucleases also known as

Answer 6

restriction enzymes or molecular scissors because restrction endonucleases are cutting down the molecuels

Question 7

where are endonucleases from

Answer 7

mostly from bacteria

Question 8

EcoRI

Answer 8

is a restriction endonuclease enzyme isolated from species E. coli

Question 9

overhanging nucleotides

Answer 9

unbonded nucleotides on the ends of the DNA strand

Question 10

circular DNA

Answer 10

plasmid

Question 11

compare thecuts between linear and circular dna

Answer 11

linear DNA has one more than circular DNA–the linear DNA has the same one more strand than the amount of cuts. eg 3 cuts linear dna will have 4 fragemnets, circular dna will have 3 cuts

Question 12

ligase

Answer 12

enzymes that join fragments of DNA, forming a phosphodiester bond after the restricton enzymes cut DNA

Question 13

why is it that the ligase is called a molecular glue, whilst restriction endo nucleases are known as moleculear scissors

Answer 13

ligase joins 2 fragments of DNA, whilst restrction endonuclease cut the sequences of DNA

Question 14

types of ligase

Answer 14

DNA ligase
RNA ligase

Question 15

differnece between polyermase and ligase

Answer 15

polymerase forms DNA and RNA from nucleotides, whereas, ligase joins DNA or RNA fragments together

Question 16

primer

Answer 16

a short strand of nucleic acids that guides the polymerase to the right place to start copying the DNA and is the starting pointto which polyermase attahche

Question 17

in the DNA sequence, the primer is always

Answer 17

at the beginning of the sequence, there should be a distinction to show where the primer is

Question 18

where are restriction enzymes foudn

Answer 18

resctrictionenzymes are foundin bacteria

Question 19

where do restriction enzymes cut and how do restriction enzymes cut

Answer 19

restriction enzymes cut a specific recognition site(code)

restriction enzymes cut specific reocngintion sites by cleaving the phosphodiester bond of the sugar-phosphate back bone.

Question 20

The recognition site of a restriction enzyme

Answer 20

specific

Question 21

how many nucleotides is a recognition site composed of

Answer 21

4-6 nucleotides

Question 22

types of restriction enzymes

Answer 22

sticky end restriction enzyme

blunt end restriction enzyem

Question 23

sticky end restriction enzymeshow is it produced and whenpairing with anotether DNA fragemnets

Answer 23

1.astaggered cut in mdae in the DNA,leaving overhanging nucleotides

2. when pairing with another DNA fragments, the exposed nucleotides must be complementary.

Question 24

Blunt end restriction enzyme

Answer 24

1. Restriction enzymes cut in the middle of the recongition site and thereofre, this straight cut leaves no overhanging nucloeitdes.

Question 25

if there are equal bases on each end of the dna sequence, then

Answer 25

its blunt sequence if not tis a sticky end(zig zag patterns)

Question 26

ligase

Answer 26

enzymes that join fragments of DNA, forming a phosphodiester bond after the restricton enzymes cut DNA

Question 27

annealing

Answer 27

process where ligase, joins fragments of DNA, forming a phosphodiester bond after the restriction enzymes cut the DNA, and leaving sticky ends complemenatary to their overhanign nucldeotiedes

Question 28

sticky ends must be

Answer 28

not even amount of bases of each side of the sqeuence and complemenatary to their overhanging nucloetides.

Question 29

polyermase

Answer 29

adds nucleotides to DNA or RNA, leading to genes being copied,

Question 30

2 types of polyermease

Answer 30

DNA and RNA polymereaese

Question 31

compare RNA polyermase and DNA polyemrease

Answer 31

RNA polyermease copies the DNA strand to produce an mRNA strand

DNA polyermease adds nucleotides to form DNA in cell replication

Question 32

what is required for polyreemase to copygenes

Answer 32

a primer