4/10/08, #1

Front 1

Delayed wound healing, hypogonadism, decreased adult hair (axillary, facial, pubic), and predisposition to alcoholic cirrhosis Sx of what disorder?

Back 1

Zinc deficiency

Front 2

What inhibits alcohol dehydrogenase?

Back 2

Fomepizole

Front 3

What drug inhibits acetaldehyde dehydrogenase?

Back 3

Disulfiram (Antabuse). Causes acetaldehyde to accumulate --> hangover symptoms.

Front 4

Ingestion of what substance leads to inc. NADH/NAD+ ratio in liver --> diversion of pyruvate to lactate and OAA to malate --> dec. gluconeog. and hypoglycemia.

Back 4

Ethanol

Front 5

What is the only histone that is not in the nucleosome core?

Back 5

H1

Front 6

Condensed, transcriptionally inactive chromatin is called what?

Back 6

Heterochromatin

Front 7

Less condensed, transcriptionally active chromatin is called what?

Back 7

Euchromatin
(Eu = true, "truly transcribed")

Front 8

Name the four histones that make up the histone octamer

Back 8

H2A, H2B, H3, H4

Front 9

How many rings do purines have?

Back 9

two

Front 10

How many rings do pyrimidines have?

Back 10

one

Front 11

Which nucleotide has a ketone?

Back 11

Guanine

Front 12

Which nucleotide has a methyl?

Back 12

Thymine

(THYmine has a meTHYl)

Front 13

Deamination of cytosine makes which nucleotide base?

Back 13

Uracil

Front 14

How many H-bonds b/w G-C?

Back 14

three
(Increased G-C bonds --> Inc. melting temperature)

Front 15

How many H-bonds b/w A-T?

Back 15

two

Front 16

Which amino acids are necessary for purine synthesis?

Back 16

Glycine, Aspartate, Glutamine (GAG)

Front 17

Which bases are made from IMP precursor?

Back 17

Purines

Front 18

Which bases are made from orotate precursor, with PRPP added later?

Back 18

Pyrimidines

Front 19

Which enzyme is responsible for converting ribonucleotides to deoxyribonucleotides?

Back 19

Ribonucleotide reductase

Front 20

Substituting a purine for purine or pyrimidine for pyrimidine is called?

Back 20

TransItion (Identical type)

Front 21

Substituting purine for pyrimidine or vice versa is called?

Back 21

transVersion = conVersion b/w types

Front 22

Which amino acid is encoded by only 1 codon?

Back 22

Methionine (AUG)

Front 23

Silent DNA mutations are often due to a base change in which position of codon?

Back 23

3rd position (

Front 24

What type of mutation results in early stop codon.

Back 24

Nonsense mutation (STOP the NONSENSE)

Front 25

What type of mutation results in changed amino acid (conservative mutation leads to new aa similar in chemical structure)?

Back 25

Missense mutation (point mutation)

Front 26

What protein unwinds DNA template at replication fork?

Back 26

Helicase

Front 27

What protein prevents strands from reannealing?

Back 27

single-stranded binding proteins (SSB)

Front 28

What is DNA gyrase?

Back 28

A specific prokaryotic topoisomerase.

Front 29

What proteins create nicks in the helix to relieve supercoils?

Back 29

DNA topoisomerases

Front 30

What class of antimicrobial drugs inhibit DNA gyrase?

Back 30

Fluoroquinolones

Front 31

What protein makes an RNA primer on which DNA polymerase III can initiate replication?

Back 31

primase

Front 32

What protein elongates the DNA chain by adding deoxynucleotides to the 3' end (leading strand)?

Back 32

DNA polymerase III

Front 33

What protein is responsible for proofreading each added nucleotide?

Back 33

3' --> 5' exonuclease

Front 34

What protein degrades RNA primer and fills in the gap with DNA?

Back 34

DNA polymerase I

Front 35

Are DNA polymerase I and III eukaryotic or prokaryotic?

Back 35

prokaryotic

Front 36

What type of enzyme does DNA polymerase use to remove RNA primer?

Back 36

5' --> 3' exonuclease

Front 37

Which enzyme seals the DNA fragments together?

Back 37

DNA ligase

Front 38

Which illness is due to a mutation in nucleotide excision repair enzymes, leading to increased susceptibility to UV light and limited ability to repair thymidine dimers?

Back 38

Xeroderma pigmentosum (dry skin w/ melanoma and other cancers, "children of the night")

Front 39

What repair mechanism is compromised in hereditary nonpolyposis colorectal cancer (HNPCC)?

Back 39

Mismatch repair

Front 40

Which type of RNA is the longest type, most abundant type, and smallest type?

Back 40

mRNA = longest
rRNA = most abundant
tRNA = smallest

(Massive, Rampant, Tiny)

Front 41

What is the mRNA initiation codon?

Back 41

AUG (or rarely GUG); AUG inAUGurates protein synthesis.

Eukaryotes: Methionine
Prokaryotes: f-Met

Front 42

What are the mRNA stop codons?

Back 42

UGA, UAA, UAG

UGA = U Go Away
UAA = U Are Away
UAG = U Are Gone

Front 43

What region of the gene is AT-rich and has TATA and CAAT boxes?

Back 43

Promoter region

Front 44

What is the site of DNA chain that negative regulators (repressors) bind?

Back 44

Silencer region

Front 45

RNA polymerase I makes which RNA?

Back 45

rRNA

Front 46

RNA polymerase II makes which RNA?

Back 46

mRNA

Front 47

RNA polymerase III makes which RNA?

Back 47

tRNA

Front 48

What substance inhibits RNA polymerase II?

Back 48

alpha-amanitin (found in death cap mushrooms)

Front 49

Name three ways that initial RNA (heterogeneous nuclear RNA, hnRNA) is processed after transcription to become mRNA?

Back 49

1) Capping on 5' end
2) Polyadenylation on 3' end
3) Splicing out of introns

Front 50

Where does RNA processing in eukaryotes take place?

Back 50

Inside the nucleus

Front 51

What is the significance of AAUAAA?

Back 51

It is the polyadenylation signal. (RNA processing in eukaryotes).

Front 52

During pre-mRNA splicing, the primary transcript combines with snRNPs and othe proteins to form what?

Back 52

A spliceosome

Front 53

During pre-mRNA splicing, what is released to remove the intron precisely and join the two exons?

Back 53

Lariat

Front 54

What part of DNA contains the actual genetic information for coding protein?

Back 54

exons (introns are intervening noncoding segments of DNA)

Front 55

All tRNAs (both euk and prok) have which sequence at the 3' end?

Back 55

CCA

Front 56

Which organisms have 80S ribosomes --> 60S + 40S

Back 56

Eukaryotes (Even)

Front 57

Which organisms have 70 S ribosomes --> 50S + 30S

Back 57

Prokaryotes (Odd)

Front 58

Which ribosomal site accepts incoming Aminoacyl tRNA?

Back 58

A site (Aminoacyl tRNA)

Front 59

Which ribosomal site accommodates growing peptide?

Back 59

P site (Peptide)

Front 60

Which ribosomal site holds empty tRNA as it exits?

Back 60

E site (Empty tRNA as it Exits)

Front 61

What is the only aminoacyl-tRNA that binds to P site?

Back 61

Initiator methionine.

Front 62

Which energy source activates tRNA (charging)?

Back 62

ATP (Activates)

Front 63

Which energy source assists tRNA with translocation and tRNA insertion into A site?

Back 63

GTP (tRNA Gripping and Going places -- translocation)

Front 64

How many high-energy phosphoanhydride bonds are used up in translation for each cycle?

Back 64

4 (two from ATP to AMP and two for two molecules of GTP to GDP)