Which of the following enzymes adds incoming deoxyribonucleotides/deoxyribonucleoside triphosphates to the 3' OH of the growing daughter strand in the 5' - 3' direction? A.Primase B.Topoisomerase C.Ligase D.Polymerase

Which of the following statements is FALSE regarding the molecular mechanism for DNA polymerases?   A. The active site contains 2 divalent metal ions   B. A single stranded DNA template is required   C. The enzyme can only attach a new deoxynucleotide to the 5’ end of a growing chain   D. The 3’OH on the deoyxyribose ring attacks a phosphate of a dNTP to produce a new phosophodiester bond   E. None of the above (all are true statements)

What is the function of DNA helicase and what is the function of the DNA polymerase?

Pyrimidine dimers in DNA may be repaired by in E. coli cells. (select all correct answers) Select one or more: O a. photolyase O b. nucleotide excision repair O c. mis-match repair O d. methyl-transferase

1. Cytosine deamination, in which cytosine is mutated to uracil, occurs spontaneously in DNA at a rate of 1 out of 107 cytosines in 24 hours. tofo NH₂ 'N cytosine deamination ----ဝိ NH spr a. If cytosine deamination occurs and DNA polymerase replicates the DNA with this altered base, what mutation would be introduced into DNA? b. Cytosine deamination is so common that DNA repair enzymes recognize uracil and replace it with cytosine. Given this information, why is it essential for DNA, the carrier of the genetic blueprint, to utilize thymine, not uracil, as a base?

32. The molecule above is called HO 08-0 OH OH and it can be found in A) 3'-deoxyribose-5'-phosphate; RNA B) 2'-deoxyribose-5'-phosphate; RNA 3'-deoxyribose-5'-phosphate; DNA D) 2'-deoxyribose-5'-phosphate; DNA 33. The chromosomes we typically con in im OH

19. Match the letters with the enzymes and macromolecules involved in DNA replication: A E B DNA POLYMERASE CATALYZES COMALENT LINKAGE OF NUCLEOSIDE TRIPHOSPHATE INTO GROWING NEW STRAND INCOMING NUCLEOSIDE D' TRIPHOSPHATE PAIRS WITH A BASE IN THE TEMPLATE STRAND A) i) pyrophosphate (Pi) ii) template strand ii) incoming nucleoside triphosphate iv) new strand v) DNA polymerase

94

Explain why H is 5' and leading strand and E is 3' and laggin strand.

36. Which is the sequence of steps used to amplify DNA with PCR during a single cycle? 1) Primers bind (anneal) to complementary sequences of the target DNA. 2) DNA is heated to a high temperature to cause denaturation (DNA is single-stranded). 3) DNA polymerase extends the 3’OH of primers to make copies of the target DNA. A) 1, 2 and 3 B) 3, 2, and 1 C) 2, 1, and 3 D) 1, 3, and 2