Exam 2 Chapter 8

Question 1

Ribonucleic acid (RNA) mediates:

Answer 1

Gene expression

Question 2

Gene expression starts with:

Answer 2

Transcription

Question 3

• 80% of total RNA

- Found associated w/ proteins in ribosome

Answer 3

Ribosomal RNA (rRNA)

Question 4

• Carries amino acids during translation

Answer 4

Transfer RNA (tRNA)

Question 5

• Only 5% of all RNA in cell

- Encodes amino acid sequence for protein synthesis

Answer 5

Messenger RNA (mRNA)

Question 6

• Regulatory and/or catalytic activity

- More than 3 other groups combined

Answer 6

MicroRNA (miRNA)

Question 7

Replication vs. Transcription

Answer 7

• Both have initiation, elongation & termination
• Only selected genes are transcribed
• Direction of synthesis is the same
• Primers are not required for transcription

Question 8

Synthesis of pre- ribosomal RNA = Precursor to RNA

Answer 8

RNA polymerase 1

Question 9

• Synthesis of mRNA & miRNA

- Requires many other proteins to function

Answer 9

RNA polymerase II

Question 10

Synthesis or tRNA

Answer 10

RNA polymerase III

Question 11

Basal promoter

Answer 11

• Expressed all the time

Question 12

Proximal component (basal promoter) = TATA box

Answer 12

Directs RNA polymerase II

Question 13

Distal component (basal promoter) = CAAT box

Answer 13

Controls frequency of transcription

Question 14

Steps in RNA synthesis

Answer 14

• Assembly
• Initiation
• Elongation
• Termination

Question 15

• Does not use primers
• RNA polymerase binds to specific DNA sequence called promoter
• Promoter is often TATA sequence
• -30 bases from start site
• Call TATA box
• Transcription factors bind together w/ RNA polymerase II

Answer 15

Transcription Initiation