DNA replication and enzymes

Question 1

Step 1 Gyrase

Answer 1

gyrase relaxes supercoiling of DNA strand

Question 2

Step 2 helicase

Answer 2

seperates double strand into single strand creating replication fork- “unzips” the DNA

Question 3

step 3

Answer 3

single stranded bind proteins stabilize the split strands

Question 4

step 4 primase

Answer 4

places primers on both strands- made from RNA

Question 5

step 5 DNA polymerase

Answer 5

begins to copy DNA into daughter strands, proofreas and repairs DNA

Question 6

leading strand

Answer 6

continuous goes 5’ to 3’

Question 7

lagging strand

Answer 7

goes from 3’ to 5’, needs several primers, made up of Okazaki fragments

Question 8

Step 6 ligase

Answer 8

glues together DNA strands and Okazaki fragments

Question 9

endonuclease

Answer 9

cut DNA backbone in a strand of DNA, facilitate repair and insertions

Question 10

exonuclease

Answer 10

cut DNA from an exposed end of DNA, facilitates repair

Question 11

methylase

Answer 11

adds methyl group to selected bases in newly made DNA

Question 12

photolyase

Answer 12

uses visable light energy to seperate UV-induced pyrimidine dimers

Question 13

ribozyme

Answer 13

RNA enzyme that removes introns and splices exons together

Question 14

RNA polymerase

Answer 14

copies RNA from a DNA template

Question 15

RNA primase

Answer 15

An RNA polymerase that makes RNA primers from a DNA template

Question 16

snRNP

Answer 16

RNA protein complex that removes introns and splices exons together

Question 17

topolsomerase

Answer 17

seperates DNA circles at the end of DNA replication, relaxes supercoiling before replication fork

Question 18

transposase

Answer 18

cuts DNA backbone, leaving single stranded “sticky ends”

Question 19

mimic DNA replication

Answer 19

C-ar in the G-arage

A-pple in a T-ree