Central Dogma and Transcription

Question 1

Central Dogma of Molecule Biology

Answer 1

DNA –> Gene –> Transcription: mRNA (messenger RNA) –> Translation: tRNA (transfer RNA) and rRNA (ribosomal RNA) –> Protein

Question 2

RNA

Answer 2

Ribonucleic Acid: single-stranded but can fold onto itself –> used to get message out of nucleus into cytoplasm

Question 3

Codon

Answer 3

Combination of 3 nucleotides

Question 4

Initiation

Answer 4

Occurs on non-coding (template) strand to have same sequence as coding strand
- RNA polymerase binds to start of gene called promoter sequence, specifically TATA box (rich in T and A nucleotides which helps enzyme break bonds)

Question 5

Elongation

Answer 5

RNA polymerase opens DNA one section at a time, and works in 5’–>3’ direction, adding nucleotides (no okazaki fragments needed, since RNA is single-stranded) –> many RNA copies can be made of same gene

Question 6

Termination

Answer 6

Stops when terminator sequence located - RNA polymerase and new mRNA detaches from DNA

Question 7

Processing

Answer 7

Only occurs in eukaryotes: first two protect/stabilize mRNA
1. 5’ cap: modified G nucleotide on 5’ end
2. Poly-A tail: long chain of A nucleotides on 3’ end
3. Splicing: introns (don’t code for proteins) removed from exons by spliceosome