Chapter 14.3.1 (Exam 3) Transcription

Question 1

Which DNA strand does RNA polymerase read during transcription?

Answer 1

The template strand (3′ → 5′ direction)

Question 2

What are the two complementary strands of DNA called?

Answer 2

Non-template strand/coding strand

Template strand/non-coding strand

Question 3

Why is the non-template strand called the coding strand?

Answer 3

While it’s not used directly for translation, its sequence matches the RNA that gets translated into protein

(The only difference being the RNA has U’s and the coding strand has T’s)

Question 4

What is necessary for transcription?

Answer 4

DNA template

Four ribonucleoside triphosphates, NTPs (ATP,GTP,CTP,UTP)

RNA polymerase

Question 5

What kind of RNAs does transcription produce?

Answer 5

mRNA, tRNA, and rRNA, encoded by specific genes

Question 6

Describe RNA polymerases.

Answer 6

RNA polymerases catalyze RNA synthesis

Question 7

What does it mean if an enzyme is processive?

Answer 7

Processive means that an enzyme can catalyze multiple consecutive reactions without detaching from its substrate

Question 8

Describe how RNA polymerases catalyze RNA synthesis.

Answer 8

Nucleotides are added in a 5’-to-3’ direction

Processive—one enzyme-template binding results in polymerization of hundreds of RNA bases

They do not need primers