NB CH21,22,23 - Central Dogma

Question 1

What direction is the RNA built in?

Answer 1

5’ → 3’, just like DNA

Question 2

What is reverse transcription?

Answer 2

Generating DNA using an RNA template

Question 3

What enzymes are involved in DNA replication?

Answer 3

Helicase, topoisomerase, primase, DNA polymerase III, DNA polymerase I, ligase, and telomerase

Question 4

What enzymes are involved in transcription?

Answer 4

RNA polymerase

Question 5

Why is helicase not required in transcription?

Answer 5

RNA polymerase can perform the job of helicase and unwind DNA

Question 6

What sites must be present in DNA so that RNA polymerase can transcribe the DNA to RNA?

Answer 6

RNA polymerase binding site/promoter
Transcription start site
Transcription stop site

Question 7

For transcription to be initiated, a special sequence of DNA is required. What is the name of this sequence?

Answer 7

The promoter

Question 8

What two things does the promoter determine?

Answer 8

Where RNA polymerase binds to DNA
Which strand of DNA is read

Question 9

What is the -10 sequence in the promoter known as?

Answer 9

TATA box

Question 10

What is promoter strength?

Answer 10

How much RNA transcript of a gene is produced from a promoter

Question 11

If there are base changes at the promoter in the DNA, will the amount of transcript produced will be affected?

Answer 11

Yes

Question 12

Splicing

Answer 12

Introns removed
Exons spliced together

Question 13

Coding/sense strand/non-template strand

Answer 13

The DNA strand whose sequence is identical to the resulting mRNA

Runs in 5’ –> 3’ direction

Question 14

Non-coding/template/antisense strand

Answer 14

The DNA strand that serves as a guide for building RNA or another strand of DNA

Runs in 3’ –> 5’ direction

Question 15

What types of RNA are involved in translation?

Answer 15

mRNA(messenger RNA)
rRNA(ribosomal RNA)
tRNA(transfer RNA)

Question 16

What is the ribosome made of?

Answer 16

Proteins and rRNA

Question 17

Which direction is mRNA read?

Answer 17

5’ → 3’

Question 18

What are codons and anti-codons?

Answer 18

Codons are nucleotide triplets that match up to an amino acid. Anti-codons are their complements

Question 19

Which RNA has the sequence for codons?

Answer 19

mRNA

Question 20

Which RNA has the sequence for anti-codons?

Answer 20

tRNA

Question 21

What are the three steps of translation?

Answer 21

Initiation, elongation, termination

Question 22

Which direction does tRNA attach to mRNA?

Answer 22

Antiparallel-ly. If mRNA is read 5’ → 3’, the tRNA will be 3’ → 5’.

Question 23

What are the 3 active sites on a ribosome and what happens on them?

Answer 23

A, P, and E sites

A site: point of entry for the tRNA (except
for the first tRNA, which enters at the P
site)

P site: where tRNA is held in the ribosome
and adds to the peptide chain

E site: exit site of the tRNA

Question 24

Missense mutation

Answer 24

A mutation that results in a
different amino acid in the peptide chain

Question 25

Nonsense mutation

Answer 25

A mutation that results in a premature “STOP” codon,

Question 26

Silent mutation

Answer 26

A mutation that has no effect on the phenotype or resulting amino acid

Question 27

What is the cause of mutations?

Answer 27

An altered reading frame, which is due to point mutations, insertions, or deletions

Question 28

What is the second law of thermodynamics?

Answer 28

The total entropy of an isolated system can never decrease over time Entropy of a system increases over time

Question 29

Circular DNA is found in which type of cell?

Answer 29

Both prokaryotic and eukaryotic cells

Question 30

In what type of cells do genes contain exons, which are interrupted by introns, which are spliced out after transcription?

Answer 30

Eukaryotes only