L2: From DNA To Protein

Question 1

DNA vs RNA

Answer 1

DNA: ATCG, Deoxyribose
RNA: AU(uracil)CG, Ribose

Question 2

Components of transcription unit

Answer 2

1. Regulator
2. Promoter
3. Structural gene
4. Terminator

Question 3

Processing of mRNA

Answer 3

5C3P

1. 5’ end: Capping at 5’ end
2. 3’ end: Adding poly-A tail
3. Intron splicing by spliceosome

Question 4

Who discovered the transcription and translation from DNA to protein

Answer 4

Marshall Nirenberg

Question 5

Start and Stop codon

Answer 5

Start: AUG
Stop:
- UAA
- UAG
- UGA

Question 6

How gene expression is regulated

Answer 6

1. DNA
   - Amplification, rearrangement
2. RNA
   - Transcription, modification, degradation
3. Protein
   - Translation, modification, degradation

Question 7

Techniques to detect gene expression

Answer 7

DNA: southern blot
RNA: northern blot, cDNA microarray
Protein: western blot

Question 8

Process of transcription

Answer 8

1. Initiation: RNA polymerase bind to promoter
2. Uncoil DNA to form template strand (3’ to 5’)
3. Elongation: add nucleotide / build mRNA from 5’ to 3’
4. Termination
5. mRNA processing

Question 9

Process of translation

Answer 9

1. mRNA: codon, tRNA: anticodon
2. mRNA bind to small ribosomal subunit + tRNA carrying amino acid —> translation initiation complex
   3.
   A site: subsequent tRNA with a.a. enters
   P site: binding of initiator tRNA
   E site: exit site
   P site polypeptide chain transferred to a.a. in A site
3. Completed polypeptide chain transported to Golgi for modification

Question 10

What is central dogma of molecular biology

Answer 10

Flow of genetic information within biological system:

DNA ⇌ RNA —> protein