Unit 3: Molecular Genetics

Question 1

nucleotide

Answer 1

5C sugar molecule + phosphate group + 1 of 4 nitrogenous bases (adenine, cyanine, thymine, guanine)

Question 2

DNA structure

Answer 2

double helix
sugar phosphates forms backbones
A-T, G-C base pairs

Question 3

RNA structure

Answer 3

single strand
A-U, G-C base pairs (uracil instead of thymine)

Question 4

semi conservative model (DNA replication)

Answer 4

the two new daughter strands would bind to a parental strand and form a double helix. each DNA molecule of the first replication would contain a parental DNA strand

initiation, elongation and termination

Question 5

helicase (DNA rep)

Answer 5

unwinds DNA during initiation

Question 6

primase (DNA rep)

Answer 6

makes RNA primer during elongation

Question 7

single-stranded binding proteins (DNA rep)

Answer 7

stabilize template strands during initiation

Question 8

topoisomerase II (DNA rep)

Answer 8

relieves strain on DNA during initiation

Question 9

DNA polymerase I (DNA rep)

Answer 9

removes RNA primers and replaces it with nucleotides

Question 10

DNA polymerase II

Answer 10

creates new daughter strand

Question 11

DNA ligase (DNA rep)

Answer 11

sealing DNA to okazaki fragments

Question 12

transcription

Answer 12

process of going from DNA to mRNA. happens in the nucleus

Question 13

intron

Answer 13

non-coding sequence, not necessary for translation

Question 14

exon

Answer 14

coding sequence, necessary for translation

Question 15

transfer RNA (tRNA)

Answer 15

responsible for reading codons on the mRNA and bringing the appropriate amino acids to the polypeptide chain.

Question 16

anti codon loop (tRNA)

Answer 16

3 nucleotides complementary to codon

Question 17

acceptor stem (tRNA)

Answer 17

amino acid attaches here

Question 18

tRNA synthetase - A site

Answer 18

charge tRNA anticodon binds to mRNA codon

Question 19

tRNA synthetase - P site

Answer 19

tRNA adds the amino acid to the chain

Question 20

tRNA synthetase - E site

Answer 20

tRNA releases amino acid and waits to be removed

Question 21

polyribosome

Answer 21

multiple ribosomes attach to mRNA at once

Question 22

operon

Answer 22

many genes under the control of one promoter region

Question 23

structural genes

Answer 23

genes that encode the enzymes in a pathway

Question 24

regulatory gene

Answer 24

codes for a repressor which can inhibit RNA polymerase from undergoing transcription

Question 25

operator

Answer 25

region where the repressor binds to inhibit transcription of structural genes

Question 26

the lac operon

Answer 26

codes for genes that help digest lactose.
if lactose is present => operon is active
if lactose is not present => operon is inactive (repressor)

Question 27

the trp operon

Answer 27

purpose is to make tryptophan (nutrient for the cell)
anabolic
when the repressor is made it is not yet active

Question 28

restriction endonuclease

Answer 28

enzyme that recognizes specific nucleotide sequences and cleaves the double stranded DNA. the enzyme will cut at the restriction site of the target sequence.

Question 29

gel electrophoresis

Answer 29

technology that separates charged molecules on the basis of sorting through meshwork

Question 30

DNA sanger sequencing

Answer 30

determine the entire genome of a bacteriophage