Test 4

Question 1

ribo vs deobyribo sugars

Answer 1

ribose sugars have an OH at C2
deoxyribo sugars have a H at C2

Question 2

purines vs pyrimidines

Answer 2

purines have two rings (AG)
pyrimidines have one ring (TCU)

Question 3

nucleotides vs nucleosides

Answer 3

nucleotides contain nitrogenous base, sugar, and phosphate group
nucleosides contain nitrogenous base and sugar

Question 4

hydrogen bonding between nucleotides

Answer 4

AT has 2 H bonds between them
CG has 3 H bonds between them

Question 5

complementary base-pairings and their relative strength

Answer 5

AT (DNA) AU (RNA)
CG - strongest bc of 3 H bonds

Question 6

DNA runs _____________

Answer 6

5’ -> 3’
3’ -> 5’ (antiparallel)

Question 7

chromatin structure

Answer 7

base unit: nucleosome
nucleosomes are 147 base pairs wrapped around histones

Question 8

what biochemical components are necessary for DNA replication

Answer 8

DNA polymerase 3
DNA gyrase
single strand DNA binding proteins
DNA initiation factor
DNA helicase
DNA primase
DNA polymerase 1 and DNA ligase complete the job started by DNA polymerase 3

Question 9

DNA replication is initiated at

Answer 9

origins of replication

Question 10

degenerative nature of genetic code

Answer 10

a single amino acid may be coded by more than one codon

Question 11

silent mutation

Answer 11

nucleotide change that does not affect the protein

Question 12

missense mutation

Answer 12

single base pair substitution alters

Question 13

nonsense mutation

Answer 13

sense codon is replaced with a stop codon

Question 14

insertion and deletion mutations

Answer 14

insertion: adding one or more nucleotides to the gene
deletion: removing one or more nucleotides from the gene

Question 15

frame-shift mutations

Answer 15

caused by insertion of deletion that results in the remainder of the codon to be read differently

Question 16

sources of chemical mutations

Answer 16

methylating agents
strong oxidizers
halogenating reagents
helix intercalators

Question 17

sources of radiation mutations

Answer 17

ionizing radiation
UV radiation

Question 18

base excision repair

Answer 18

dual incision excision of the base
DNA ligase repairs and resynthesizes

Question 19

operator

Answer 19

regulatory sequence lying adjacent to the promoter

Question 20

promoter

Answer 20

nucleotide sequence that binds to RNA polymerase

Question 21

attenuator

Answer 21

results in the premature termination of transcription

Question 22

terminator sequences

Answer 22

cause transcription to stop

Question 23

enhancer sites

Answer 23

increase transcription

Question 24

ribonucleotides

Answer 24

phosphate group, ribose sugar, nucleobase (AGCU)

Question 25

secondary structures of RNA

Answer 25

bases of an individual molecule can pair with one another (G-C, A-U) causing RNA to fold

Question 26

prokaryotic operons vs eukaryotic operons

Answer 26

polycistronic/genomic (introns and exons) Exons = Expressed

Question 27

alternative splicing

Answer 27

exons from the same gene are joined in different combinations, leading to different mRNA transcripts

Question 28

transcriptional repression

Answer 28

proteins that bind to promoters that impede binding of RNA polymerase

Question 29

transcriptional depression

Answer 29

substrate binds to a repressor protein and causes it to undergo a conformational change

Question 30

most transcriptional activators bind to

Answer 30

enhancers

Question 31

transcription regulators in prokaryotes

Answer 31

activators

Question 32

transcription regulators in eukaryotes

Answer 32

repressors

Question 33

bacterial transcription

Answer 33

transcription and translation occur simultaneously in the cytoplasm

Question 34

eukaryotic transcription occurs in the _____________ and translation occurs in the ____________

Answer 34

nucleus, cytoplasm

Question 35

3 major modifications to most eukaryotic mRNA transcripts prior to translation

Answer 35

5'-capping, splicing of introns, polyA tails

Question 36

purpose of the 5' cap

Answer 36

methylated cap protects the transcript from being degrated

Question 37

RNA polymerase 1

Answer 37

synthesis of rRNA genes (nucleolus)

Question 38

RNA polymerase 2

Answer 38

synthesis of mRNA genes

Question 39

RNA polymerase 3

Answer 39

synthesis of tRNA genes

Question 40

poly-A tail

Answer 40

slows degrading

Question 41

components of DNA replication

Answer 41

DnaA, ss DNA binding proteins, helicase, primase, DNA polymersase

Question 42

components of RNA transcription

Answer 42

RNA polymerase, sigma initiation factor, P termination factor

Question 43

DNA replication is ______, __________, and ________

Answer 43

semi-conservative, bidirectional, discontinuous

Question 44

RNA replication is ________ and __________

Answer 44

unidirectional and continuous

Question 45

ribosome binding site

Answer 45

RNA sequence found in mRNA to which ribosomes can bind and initiate translation

Question 46

start codons

Answer 46

AUG first codon in the transcribed mRNA that undergoes translation

Question 47

termination codons

Answer 47

UGA, UAA, UAG signals the termination of the translation process

Question 48

protein synthesis in the

Answer 48

cytoplasm -> ribosomes

Question 49

mRNA role in protein synthesis

Answer 49

carry coding sequences for protein synthesis

Question 50

rRNA role in protein synthesis

Answer 50

hold the construction of protein amino acid sequences

Question 51

tRNA role in protein synthesis

Answer 51

supply and configure the protein sequence coded on the mRNA

Question 52

glycosylation

Answer 52

occurs in the ER and golgi apparatus addition of sugars to specific amino acids, affects 3-D configuration of proteins

Question 53

mechanism for eliminating misfolded and non functional proteins

Answer 53

proteasomes (specifically ubiquitin-proteasome)

Question 54

cellular components that are involved in protein synthesis

Answer 54

nucleus RER ribosomes golgi apparatus

Question 55

steps in protein synthesis

Answer 55

initiation elongation termination