Transcription and Translation

Question 1

Process of DNA to protein

Answer 1

DNA - mRNA transcription - mature mRNA - transport to cytoplasm - to ribosome - make protein (synthesis)

Question 2

Template strand is

Answer 2

3’ to 5’.

aka ANTISENSE

Question 3

Enzyme needed to form complementary RNA sequence from template DNA strand

Answer 3

RNA polymerase

Question 4

Raw materials for transcription

Answer 4

DNA, transcription factors, RNAp, ATP.

Question 5

Transcription begins at

Answer 5

1. TATA box (i.e. promotor) and enhancer region.

2. at the TRANSCRIPTION UNIT portion of gene

Question 6

TF2D factor

Answer 6

TBP component on it binds to TATA box on DNA.

TF2B and TF2A then attach. RNAp can now bind.

Other TF’s can bind to it to mature it.

Question 7

RNAp reads from

Answer 7

3’ to 5’ on antisense

Question 8

RNAp generates from

Answer 8

5’ to 3’ of new mRNA strand

Question 9

TRANSLATION

tRNA function:

Answer 9

tRNA carries amino acids to ribosome
mRNA is read 3 bases at a time.
As each triplet (codon) is read a tRNA transfers corresponding aa to growing chain.

chain folds –> protein

Question 10

1 codon =

Answer 10

3 bases = 1 amino acid coded for

Question 11

PARTS OF A GENE: TRANSCRIPTION.

1) Promoter and beginning transcription.

Answer 11

On the gene itself:

PROMOTER REGION

• 25 to -30 bp’s upstream from TSS.
• has the TATA box
• RNAp binds to the promoter region
• RNAp2 - catalyzes synthesis of mRNA precursors for all protein coding genes

Question 12

PARTS OF A GENE: TRANSCRIPTION.

2) pre mrna processing

Answer 12

DNA - primary RNA transcript - mRNA matured - into cytosol - protein.

gene –> primary transcript/pre-mRNA (addition of cap at 3’ poly A TAIL by enzyme and CAP at 5’ end by ) –> Removal of introns, joining of exons (spliceosome) –> mature mRNA

Question 13

post transcriptional processing

Answer 13

1. Cap addition at the 5’ end (5’ – 5’ triphosphate bridge)
   • Capping enzyme mRNA guanylyltransferase adds a
   7–methylguanylate cap; methylated cap or m7G
2. Poly (A) tail addition at the 3’ end
   • polyadenylase
3. Splicing
   • spliceosome

Question 14

What are the parts of a gene?

Answer 14

PROMOTER REGION –> TSS –> START CODON – INTRONS / EXONS – STOP CODON –> POLYADENLATION SITE –> TTS

Question 15

Does pre-MRNA include exons and introns?

Answer 15

Yes

Question 16

One word to describe the genetic code is:

Answer 16

degenerate.

A code in which several code words have the same meaning. The genetic code is degenerate because there are many instances in which different codons specify the same amino acid. A genetic code in which some amino acids may each be encoded by more than one codon.

Question 17

Steps in gene expression

Answer 17

1. Alteration in chromatin structure
2. Transcription initiation
3. Transcript elongation
4. Termination of transcription
5. RNA processing
   a. capping
   b. polyadenylation
   c. splicing
6. Nucleocytoplasmic transport
7. Translation
8. mRNA degradation

Question 18

Regulation of gene expression

Answer 18

Histone modification
and DNA
methylation

Transcriptional
activation or
repression

Premature
termination

Alternative splicing

Control of
translation

mRNA degradation –> stability