Genetics Exam 1 Part 2

Front 1

What does DNA helicase do?

Back 1

it separates the DNA strands for replication

Front 2

dna gyrase

Back 2

travels ahead of helicase to alleviate supercoiling for replication

Front 3

single-strand binding protein

Back 3

keep separate DNA strands apart for replication

Front 4

DNA primase function

Back 4

make short RNA primers for replication

Front 5

RNA primers

Back 5

strands of nucleotides during DNA synthesis. leading DNA strand has one primer, lagging DNA strand has several primers because the Primase can only travel from the 3'-5' end of the dna strand

Front 6

What initiates DNA replication

Back 6

DnaA proteins binding to DnaA box sequences

Front 7

function of DNA protein

Back 7

binds to DnaA boxes within origin to initiate DNA replication

Front 8

function of DNA helicase

Back 8

separates double-stranded DNA

Front 9

Topoisomerase function

Back 9

removes positive supercoiling ahead of replication fork

Front 10

single-strand binding protein function

Back 10

binds to single-stranded DNA and prevents it from reforming a double stranded structure

Front 11

function of DNA polymerase III

Back 11

synthesizes DNA in leading and lagging strands

Front 12

function of DNA polymerase I

Back 12

removes RNA primers, fills gaps with DNA

Front 13

function of DNA ligase

Back 13

covalently attaches Okazaki fragments

Front 14

replisome

Back 14

complex of closely associated proteins that forms at replication fork during DNA synthesis in bacteria

Front 15

protein

Back 15

one or more polypeptide

Front 16

polypeptide

Back 16

chain of amino acids coded for by a gene

Front 17

transcription

Back 17

copying DNA into an RNA sequence

Front 18

structural genes

Back 18

encode amino acids of polypeptides

Front 19

transcription of structural gene produces

Back 19

mRNA

Front 20

how many DNA strands are transcribed in transcription?

Back 20

only one

Front 21

codon

Back 21

3-nucleotide sequence in mRNA that specifies a specific amino acid

Front 22

What is the strand that is transcribed?

Back 22

the template strand. the unused strand is the coding or sense strand

Front 23

What requires an overhang when being synthesized?

Back 23

DNA during replication

Front 24

What carries out transcription?

Back 24

RNA polymerase

Front 25

What direction is RNA synthesized?

Back 25

5'-3'

Front 26

three stages of transcription

Back 26

initiation, elongation, termination

Front 27

transcription initiation stage

Back 27

polyermase binds to the promoter of the DNA

Front 28

elongation stage of transcription

Back 28

DNA polyermase slides along DNA in an open complex to synthesize RNA

Front 29

termination stage of transcription

Back 29

terminator reached and polyermase and RNA detach from the DNA

Front 30

mRNA

Back 30

encodes amino acid sequence in a polypeptide. in bacteria, some encode one polypeptide and some encode more; in eukaryotes each mRNA encodes a single polypeptide

Front 31

tRNA

Back 31

transfer RNA; needed for translation of mRNA; bring amino acids to ribosomes during translation

Front 32

rRNA

Back 32

ribosomal RNA; needed for translation of mRNA; ribosomes composed of rRNA and protein subunit

Front 33

viral RNAs

Back 33

virus RNA genome; packaged within viral capsid

Front 34

promoters

Back 34

direct exact location for initiation of transcription

Front 35

consensus

Back 35

most commonly occuring bases in various promoters

Front 36

the enzyme that catalyzes RNA synthesis in bacteria is

Back 36

RNA polyermase

Front 37

How can RNA be modified?

Back 37

trimming of rRNA and tRNA transcripts; 5' capping and 3' polyA tailing of mRNA transcripts

Front 38

How is eukaryote transcription different than bacteria transcription?

Back 38

1. contains introns

2. needs to be exported from nucleus to cytoplasm

3. needs to be protected for exonucleases in cytoplasm