Chapter 7

Question 1

Transcription

Answer 1

Process of transferring genetic information coded in DNA into messenger RNA (mRNA)

Question 2

Translation

Answer 2

Process by which genetic information in the messenger RNA directs the order of amino acids in protein

Question 3

Template

Answer 3

Strand of nucleic acid that a polymerase uses to synthesize a complementary strand

Question 4

Anti-parallel

Answer 4

Term used to describe opposing orientations of the two strands of DNA in the double helix; one strand is oriented into the 5’ to 3’ direction and its complement is oriented in the 3’ to 5’ direction

Question 5

Primer

Answer 5

RNA molecule that initiates the synthesis of DNA

Question 6

Primase

Answer 6

Enzyme that synthesizes small fragments of RNA to serve as primers for DNA synthesis during DNA replication

Question 7

DNA polymerase

Answer 7

Enzymes that synthesize DNA; they use one strand as a template to generate the complementary strand

Question 8

RNA polymerase

Answer 8

Enzyme that catalyze a the synthesis of RNA using a DNA template

Question 9

Origin of replication

Answer 9

Distinct region if a DNA molecule at which replication is initiated

Question 10

Okazaki fragments

Answer 10

Nucleic acid fragment synthesized as a result of the discontinuous replication of the lagging strand of DNA

Question 11

DNA ligase

Answer 11

Enzyme that forms covalent bonds between adjacent fragments of DNA

Question 12

DNA gyrase

Answer 12

Enzyme that helps relieve the tension in DNA caused by the unwinding of the two new strands of the DNA helix

Question 13

Plus strand

Answer 13

(1) the DNA strand that is complementary to the strand used as a template for RNA synthesis (2) of the two RNA molecules that can theoretically be transcribed from double-stranded DNA, the one that can be translated to make a protein, also called the sense strand

Question 14

Minus strand

Answer 14

(1) the DNA strand used as a template for RNA synthesis (2) the complement to the plus (or sense) strand of RNA. Also called the antisense strand

Question 15

Polycistronic

Answer 15

An mRNA molecule that carries more than one gene

Question 16

Promoter

Answer 16

Nucleotide sequence to which RNA polymerase binds to initiate transcription

Question 17

Sigma factor

Answer 17

Component of RNA polymerase that recognizes and binds to the promoter

Question 18

Reading frame

Answer 18

Grouping of a stretch of nucleotides into sequential triplets; an mRNA molecule has 3 reading frames but only one is typically used in translation

Question 19

Codon/anticodon

Answer 19

Codon - set of 3 nucleotides

Anticodon - sequence of 3 nucleotides in a tRNA molecule that is complementary to a particular codon in mRNA

Question 20

A - site

Answer 20

Site on the ribosome to which tRNAs enter to donate their amino acid; acceptor site

Question 21

P - site

Answer 21

Ate on the ribosome where the tRNA that temporarily carries the elongating amino acid chain resides

Question 22

Introns/exons

Answer 22

Introns - part of the eukaryotic chromosome that does not code for a protein; removed from the RNA transcript before the mRNA is translated
Exons - portions of eukaryotic genes that are expressed; interrupted by introns

Question 23

Inducer

Answer 23

Substance that activates transcription of certain genes

Question 24

Repressor

Answer 24

Protein that binds to the operator site and prevents transcription

Question 25

Operator

Answer 25

Region located immediately downstream of a promoter to which a depressor can bind.; binding of the repressor to the operator effectively prevents RNA polymerase from progressing past that region and blocks transcription

Question 26

Operon

Answer 26

Group of linked genes whose expression is controlled as a single unit