RNA

Question 1

What are chromosomes made of?

Answer 1

DNA + histone proteins

Question 2

What is the role of messenger RNA (mRNA)?

Answer 2

Bring information to make a new protein and it acts as a template for a new protein to produce

Question 3

What is the role of ribosomal RNA (rRNA)?

Answer 3

Site where protein synthesis occurs

Question 4

What is the role of transfer RNA (tRNA)?

Answer 4

Bring amino acids to the ribosomal subunits, where protein synthesis takes place

Question 5

What is transcription?

Answer 5

The process of making mRNA

Question 6

What is needed for transcription?

Answer 6

1. DNA
2. RNA polymerase
3. rNTP - A, U, C, G
4. Transcription factors requried to carry the RNA polymerase and complete the mRNA synthesis
5. ATP

Question 7

What are the steps of transcription?

Answer 7

1. RNA polymerase binds tightly to a promoter
2. RNA polymerase opens up the DNA helix
3. The polymerase adds new RNA nucleotides that are complementary to the template DNA
4. mRNA is made

Question 8

How is mRNA processed after transcription?

Answer 8

1. Adding a cap at the 5’ end
2. Adding a poly-A tail at the 3’ end
3. introns are cut out

Question 9

What are the steps of initiation in Translation?

Answer 9

1. Small ribosomal subunit attaches to the mRNA close to the start codon.
2. Anticodon of the initiator tRNA methionine complex pairs with this codon.
3. Large ribosomal subnit joins to the small ribosomal subunit

Question 10

What are the steps of Elongation in translation?

Answer 10

1. Two tRNA can be at a ribosome at one time.
2. The tRNA at the P site passes its peptide to the tRNA at the A site
3. The tRNA at the P site leaves.
4. The ribosome moves forward and the tRNA-peptide complex is not at P site. A new tRNA amino acid can come to the A site now

Question 11

What are the steps of termination in translatioon?

Answer 11

1. When stop codon appears at the A site of a ribosome, termination occurs.
2. A protein called release factor binds to the stop codon and cleaves the poly peptide from the last tRNA

Question 12

What are the properties of tRNA?

Answer 12

1. 10 to 15% of total RNA
2. tRNA acceptor stem carries amino acid
3. tRNA triplet anto-codon sequence can bond to complementary mRNA codon sequence

Question 13

How many triplet codon are there?

Answer 13

64

Question 14

How many amino acids are there?

Answer 14

20

Question 15

how many triplet codon code for amino acid?

Answer 15

61

Question 16

how many triplet codon code for STOP codon?

Answer 16

3