Biochem Ch.24

Front 1

monomer units of DNA and RNA are called?

Back 1

nucleotides

Front 2

a nucleotide consists of?

Back 2

1) nitrogen containing heterocyclic base
2) a ribose or deoxyribose sugar
3) a phosphoric acid unit

Front 3

major purine bases

Back 3

1) adenine
2) guanine

Front 4

mojor pyrimidine bases

Back 4

1) cytosine
2) thymine
3) uracil (only in RNA)

Front 5

what is the repeating unit of the DNA or RNA?

Back 5

a nucleotide

Front 6

in RNA, nitrogen base is attached?

Back 6

beta to the ribose

Front 7

in DNA, nitrogen base is attached?

Back 7

beta to deoxyribose

Front 8

sugar in nucleotide is phosphorylated at?

Back 8

carbon 5

Front 9

naming purine
adenine and guanine

Back 9

--osine
adenosine and guanosine

Front 10

naming pyrimidenes
cytosine, thymine, and uracil

Back 10

--idine
cytidine, thymidine, and uridine

Front 11

dTMP

Back 11

deoxythymidine 5-monophosphate

Front 12

dAMP

Back 12

deoxyadenosine 5-monophosphate

Front 13

dCMP

Back 13

deoxycytidine 5-monophosphate

Front 14

UMP

Back 14

uridine 5-monophosphate

Front 15

GMP

Back 15

guanosine 5-monophosphate

Front 16

when nucleotides polymerize, the 5 phosphate on one unit esterifies to?

Back 16

the 3 OH on another unit

Front 17

the terminal 5 unit retains the?

Back 17

phosphate

Front 18

the most common form of DNA is?

Back 18

B form

Front 19

DNA structurs was determined by?

Back 19

Watson and Crick in 1953

Front 20

DNA consisits of?

Back 20

2 chains of nucleotides coiled around one another in a RIGHT handed double helix

Front 21

the chains run?

Back 21

antiparallel

Front 22

the chains are held together by?

Back 22

hydrogen bonding between compimentary base pairs

Front 23

how many H bonds between A=T

Back 23

2

Front 24

how many H bonds between G=C

Back 24

3

Front 25

the 2 strands of DNA are saide to be?

Back 25

complimentary

Front 26

what are complementary strands?

Back 26

the opposite strands of the double helix are H-bonded to one another such that A=T, G=C are always paired

Front 27

major groove

Back 27

1) outside diameter = 2nm
2) interior diameter = 1.1 nm

Front 28

minor groove

Back 28

1) length of one turn of helix = 3.4 nm
2) contains 10 base pairs

Front 29

what are in the core of the helix?

Back 29

H-bonded base pairs

Front 30

backbone of B DNA segment?

Back 30

sugar-phosphate backbone

Front 31

choromosomes?

Back 31

pieces of DNA

Front 32

chromosomes contain?

Back 32

genetic instructions or genes

Front 33

prokaryotes

Back 33

1) single chromosome
2) NO true nucleus

Front 34

prokaryote

Back 34

an organism with simple celluler structure in which there is no true nucleus enclosed by a nuclear membrane and there are no true membrane-bound organelles in the cytoplasm

Front 35

eukaryote

Back 35

1) # and size of choromosomes vary
2) true nucleus
3) nucleosome

Front 36

eukaryote

Back 36

an organism having cells containing a true nucleus enclosed by a nuclear membrane and having a variety of memebrane-bound organells that segregate different cellular functions into different compartments

Front 37

what is nucleosome?

Back 37

the first level of chromosome structure consisting of a strand of DNA wrapped around a small disk of histone proteins

Front 38

RNA structure

Back 38

1) sugar-P backbone
2) ribonucleotide
3) linked by 3'-5' phosphodiester bonds

Front 39

RNA molecules usually

Back 39

single stranded

Front 40

deoxyribose is replaced by (RNA)?

Back 40

ribose

Front 41

thymine is replaced by (RNA)?

Back 41

uracil

Front 42

replication

Back 42

DNA duplicates itself

Front 43

transcription

Back 43

RNA is made on a DNA template

Front 44

translation

Back 44

protein is synthesized from AAs and the 3 RNAs

Front 45

reverse transcription

Back 45

RNA directs synthesis of DNA

Front 46

transfer RNA (tRNA)

Back 46

1) transfers AAs to the site of protein synthesis (ribosomes)
2) has the anticodon

Front 47

ribosomal RNA (rRNA)

Back 47

rRNA forms ribosomes by reacting with proteins

Front 48

messenger RNA (mRNA)

Back 48

1) directs the AA sequence of proteins
2) is a complimentary copy of a gene
3) has the codon for an AA in a protein

Front 49

transfer RNA

Back 49

1) single stranded
2) about 80 nucleotides

Front 50

the overall shape structure of tRNA is?

Back 50

cloveleaf in a L-shaped conformation

Front 51

transcription is catalyzed by?

Back 51

RNA polymerase

Front 52

4 steps of transcription

Back 52

1) RNA polymerase binds to promoter region
2) initiation
3) chain elongation
4) termination

Front 53

chain elongation forms?

Back 53

3'-5' phosphodiester bond

Front 54

eukaryote mRNA must be processed

Back 54

1) 5' cap structure is added
2) 3' poly A tail is added
3) extrons are cut out
4) introns are spliced together

Front 55

extrons

Back 55

noncoding base sequences

Front 56

introns

Back 56

coding sequences

Front 57

what help recognize intron-extron boundaries?

Back 57

splicosomes

Front 58

splicosomes are composed of?

Back 58

small nuclear ribonucleoproteins (snRNPs)

Front 59

the genetic code (DNA)

Back 59

the message on DNA translated to mRNA
1) degenerate
2) specific
3) nonoverlapping and commaless
4) universal

Front 60

1) generate

Back 60

more than one 3-base codon can code for the same AA

Front 61

2) specific

Back 61

each codon specifies one AA

Front 62

3) nonoverlapping and commaless

Back 62

1) none of the bases are shared between consecutive codons
2) no noncoding bases appear in the base sequence

Front 63

4) universal

Back 63

except in a few instances, all organisms use the same codon

Front 64

all 64 codons have meaning

Back 64

1) 61 code for an AA
2) 3 code for the "stop" signal

Front 65

protein synthesis is called?

Back 65

translation

Front 66

protein synthesis is carried out on?

Back 66

ribosomes, complexes of rRNA and proteins

Front 67

the mRNA plus the multiple ribosomes are called?

Back 67

a polysome

Front 68

tRNA binds a specific AA aided by?

Back 68

aminoacyl tRNA synthethase

Front 69

the genetic code (DNA)

Back 69

the message on DNA translated to mRNA
1) degenerate
2) specific
3) nonoverlapping and commaless
4) universal

Front 70

1) generate

Back 70

more than one 3-base codon can code for the same AA

Front 71

2) specific

Back 71

each codon specifies one AA

Front 72

3) nonoverlapping and commaless

Back 72

1) none of the bases are shared between consecutive codons
2) no noncoding bases appear in the base sequence

Front 73

4) universal

Back 73

except in a few instances, all organisms use the same codon

Front 74

translation process

Back 74

1) initiation
2) chain elongation
3) termination

Front 75

1) initiation

Back 75

1) initiation factors (proteins)
2) mRNA
3) initiator tRNA
4) small and large ribosomes
---come together---

Front 76

P-site binds to?

Back 76

the growing peptide

Front 77

A-site binds to?

Back 77

the aminoacyl tRNA

Front 78

2) chain elongation

Back 78

1) aminoacyl tRNA binds to A-site
2) peptide bond formation
3) translocation (movement) of ribosome down the mRNA chain to next codon

Front 79

3) termination

Back 79

1) upon finding a "stop" codon a release factor binds a the empty A site
2) the bond between the last AA and peptidey tRNA is hydrolyzed releasing the protein

Front 80

mutations

Back 80

are mistakes introduced into the DNA sequence of an organism

Front 81

1) point

Back 81

substitution of a single nucleotide for another

Front 82

2) deletion

Back 82

one or more nucleotides are lost

Front 83

3) insertion

Back 83

one or more nucleotides are added

Front 84

mutagens

Back 84

1) chemicals causing a change in the DNA sequence
2) also carcinogens

Front 85

UV light causes formation of?

Back 85

a pyrimidine dimer on a DNA strand

Front 86

failure to repair this defect (pyrimidine dimer) can lead to?

Back 86

xeroderma pigmentosum

Front 87

restriction enzymes

Back 87

are bacterial enzymes that cut the backbone of DNA at specific nucleotide sequences