Lec. 27 - Transcription

Question 1

Describe the path of protein formation. (DNA, RNA, Location)

Answer 1

Gene > DNA > Chromosome > Cell/Nucleus > Organism

Question 2

Compare transcription in prokaryotes vs. eukaryotes.

Answer 2

Prokaryotes:
- Transcrip. and transla. BOTH in cytoplasm
- DNA and RNA in cytoplasm
- RNA poly. binds directly to promoter
- Makes RNA
- No introns

Eukaryotes:
- Transcrip. in nucleus, transla. in cytoplasm
- DNA in nucleus, RNA travels in and out of nucleus
- RNA poly. binds to TATA box
- Makes pre mRNA
- Exons and introns

Question 3

Describe steps of transcription.

Answer 3

1. Initiation: occurs when the enzyme RNA polymerase bonds to promoter.
2. Elongation: addition of nucleotides to the mRNA strand.
3. Termination: ending, occurs when RNA polymerase crosses a stop sequence in the gene.

Question 4

Explain the template vs. non-template strand of DNA.

Answer 4

Coding strand = same as RNA
Non-coding strand: complementary to RNA

Question 5

Explain the central dogma.

Answer 5

A theory stating genetic information only flows one way.

Question 6

Describe mRNA processing.

Answer 6

Each end of a pre-mRNA molecule is modified in a particular way.