2.7

Question 1

what were the 3 theories of dna replication?

Answer 1

1. conservative
2. semi-conservative
3. dispersive

Question 2

what is rna polymerase?

Answer 2

a protein that unwinds and separates dna and links nucleotides to one of the dna strands via complementary base paring during transcription

Question 3

what is dna polymerase?

Answer 3

a protein that links nucleotides to the pre-existing strands via complementary base pairing to form 2 new identical strands during dna replication

Question 4

how many codons exist?

Answer 4

64

Question 5

what is the full name of trna?

Answer 5

transfer rna

Question 6

what is the full name of mrna?

Answer 6

messenger rna

Question 7

what is the centrifugal pattern expected of semi-conservative replication?

Answer 7

a thin middle band of mixed dna and a thick top band of new dna

Question 8

what does the centrifuge do?

Answer 8

it separates material by mass

Question 9

what are the 4 things that happens during PCR?

Answer 9

denaturation
1. dna is mixed with primers, heated up to 95c to split the strands
annealing
2. the temperature is then lowered to 53c to allow primers to anneal
elongation
3. at 73c Taq dna polymerase adds free nucleotides at a fast rate
4. this process is repeated

Question 10

what is meant by a universal genetic code?

Answer 10

means that the genetic code is the same in all living organisms with some minor exceptions

Question 11

what happens during translation?

Answer 11

1. mrna binds to the small sub-unit of the ribosome
2. trna binds to the first complimentary anticodon and a second trna then binds after
3. a peptide bond forms between the amino acids and the first rna leaves
4. the ribosomes move from 5’ to 3’, to the next codon and the next trna binds
5. the process repeats until a stop codon is reached

Question 12

what is an application of the universality of the genetic code?

Answer 12

the production of human insulin by bacteria

Question 13

what is transcription?

Answer 13

the synthesis of mrna from a template dna strand

Question 14

what is the polymerase chain reaction?

Answer 14

a method of artificial dna copying that is useful when only small quantities are obtained

Question 15

what is translation?

Answer 15

the synthesis of a protein from an mrna template strand

Question 16

how is human insulin produced by bacteria?

Answer 16

the gene for insulin can be transferred from humans to E-coli, which then produce insulin that can be used to treat diabetes

Question 17

PCR is performed with which enzyme and why?

Answer 17

• Taq dna polymerase from hot spring bacteria
• because it is heat resistant and denaturation

Question 18

what is the function of Taq dna?

Answer 18

an enzyme that adds nucleotides to the template strand incredibly quickly

Question 19

define primer annealing

Answer 19

the process of joining of single-stranded DNA or RNA by hydrogen bonds to form a double-stranded polynucleotide. It occurs between complementary sequences only.