BIOL 112 Chapter 16: Textbook Notes on Chapter 16

Place the following steps of DNA replication in right chronological order.
1. Primase adds an ribonucleotide primer
2. Initiator proteins bind the origin of replication and helicase breaks hydrogen bonds between complementary bases of double stranded template DNA
3. DNA polymerase III extends by complementary base pairing deoxyribonucleotides to the template strands
4. Ligase phosphodiester bonds the nucleotides to connect okazaki fragments nad connect fragments at the origin and where the "crotches or forks" collide
5. DNA polymerase I removes RNA primer and replaces with Deoxyribonucleotides

1. What is a template strand? A coding strand? 2. What enzyme synthesizes mRNA. 3. How many RNA polymerases do Bacteria have? Eukaryotes? 4. What is a sigma? How is it related to the RNA polymerase? 5. What is required for transcription to begin? 6. Why are the several different types of sigma?

Indicate whether eac is true for gene expression in prokaryotes,eukaryotes or both:

1. After transcription, a 3' poly- A tail and a 5' cap areaddeddto the RNA.

2. Translation of mRNA can begin before transcription iscomplete.

3. RNA polymerase binds to the promoter region to begintranscription

4. RNA polymerase can only add a robonucleotide to the 3' end ofthe growing RNA

5. The mRNA transcript is the exact complement of the gene fromwhich it was copied.