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UWorld wrong answers - but that ill get right next time, YAY! > UWorld mix Aug 7th > Flashcards

UWorld mix Aug 7th Flashcards

1
Q

isomers that differ in their connectivity are called

A

consitutuional isomers

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2
Q

isomers that can be the same with rotation around bond

A

conformational

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3
Q

isomers that you would need to break bond to ake the same

A

configurational

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4
Q

configurationa isomer that is due to resticted movment (ie doube bond)

A

geometric, cis-trans isomer

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5
Q

do conformational isomers fall under diasterosomers?

A

no, it goes constitutional or steriososmers

and then steriosomers can be conformational or configurational and the configurational can be geometic, diasteriomers or enantiomers

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6
Q

describe one way geometric isomers can be seperated?

A

by GC bc they have different bp’s

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7
Q

is proline polar or non-polar

A

non-polar

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8
Q

are the acidic and basic amino acids hydrophilic?

A

yes, they are charged

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9
Q

tyrosine and cystine are a point of confusion

A

they both have polar bonds,

on own polar (SH bond)
when cysteine is S-S bonded - hydrophobic

tyrosine hydrophobic is the consensus- but can kinda be both

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10
Q

methionine

A

non-polar bc methyl attached to it

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11
Q

tyrosine

A

kaplan says relativley polar bc OH

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12
Q

how to determine R and S if H is in line with plane (not out, not in)

A
  1. pretend you are looking at it from side ( see if can figure it out
  2. rotate it, when we rotate the outy- stays put - think like your holding the massage spide thing from the top and rotate the other 3 prongs
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13
Q

tryptophan

A

non-polar - funky one with 2 righgs, aromatic

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14
Q

phenols with strong oxidizing agent

A

turn into quinones ( which are phenols but with the H’s removed and double c=o bonds) and only 2 double bonds on the ring - so usually not aromatic

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15
Q

ubiquinone(electron carrier) can be reduced to

A

ubiquinol (has OH)

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16
Q

how can alcohols serve as protecting groups

A

by reacting them with aldehydes or ketones they turn them to ketals and acetals which will protect the aldyhede and ketones - to remove them react with acid

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17
Q

why react alcohol with mesylate or tosylate?

A

so they attach to OH and become a leaving group - used for Nu subsitution (bc Oh is normally not that great)

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18
Q

sketcher synth

A

aldehyde, NH4Cl, and CN

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19
Q

irreversible rxns tend to be under _______ control and these favour

A

kinetic, low temp and the most favourable product is the one with the lowest activation energy

  • the lowest activation energy reaction will yeild the most productive
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20
Q

reversible rxns tend to be under ________ which favours

A

thermodynamic control, high temps

  • under these conditions all products form readily, and the most stable product will be favoured
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21
Q

how do you determine the most stable product

A

the lowest delta G

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22
Q

at 298K which products would be favoured

A

this is a low temp = irreversible rxn under kinetic control (this was stated in the passage- I missed it ) —> the product that is favoured will be the one with the lowest activation energy

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23
Q

when passage reads the reaction is irreversible what can we infer

A

that they are under kinetic control, so when deciding which product is favoured - look for activation energies

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24
Q

unit reaction rate is measured in

A

concentration of reactants used up or concentration of products produced over time

so a high rxn rate = fast rate

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25
how is rate constant k related to T and activation energy
with Arrenhius equation k= Ae^-Ea/RT but get rid of negative expo by putting it in the denominator
26
when temp increases what happens to k
k increases exponentially
27
when Ea decreases what happens to k
k increases exponentially
28
when catalyst is added what happens to k
lower Ea, lower denominator = greater k = faster rate
29
what is the relevance of an equivalence point
at this point exactly enough (equal molar quantity) of base has been added to completly neutralize acid - so if 50ml of 0.1M H2CO3 t titrated with 2M NaOH, then the mols of acid are 0.005, meaning that we need 0.005 mols of acid at the first equivalence poiint - we are told 2M NaOH is the titrant --> so need 0.025ml to make 0.005
30
adiabatic
no heat exange
31
interferon
peptide signal that interfers with virual replication - they induce production of RNaseL which cleaves RNA in cels to reduce the ability for virus to replicate
32
how can the host stop viral replication
by stropping viral transcription and translation --> this is what interferons do
33
what enzyme synthesises new DNA strand in replication euk and prok?
pro- DNA polymerase III euk - DNA polymerase a,g,e
34
what enzyme removes RNA primer?
pro- DNA polymerase 1 euk- RNase H then filled with DNA polymerase 1 (pro) and DNA polymerase g (euk)
35
monocistronic vs polycistronic
eukaryotic mRNA is monocitronic meaning that each mRNA translates to only one protein but in prokatyotes, DNA is polycistronic, so starting translating at different parts on mRNA molecule can result in dif proteins
36
what is eukaryotes mRNA
Monocistronic mRNA is a mRNA that encodes only one protein and all eukaryotic mRNAs are monocistronic
37
what enzyme activates tRNA
aminoacyl-tRNA synthetase (requires ATP)
38
what organic chem rxn happens when tRNA is activated
CA (on aminoacid) + OH on tRNA 3' end = an ester!
39
sequence on the 3' end of tRNA
CCA
40
the activated tRNA has stored energy in its eter bonf- what does this power
translater - peptide bond later on
41
where is rRNA synthesized
in the nucleolous
42
ribozymes
enzymes made of rna instead of proteins ribozymes help catalyze peptide formation
43
how doe you read anticodond
5' to 3' but this looks backwards - so just be careful with these questions
44
how to remeber stop codons
U Are Annoying U Go Away U Are Gone
45
nonsense vs missense
this nonsense has to STOP missense is one aa for another
46
in eurkaryotes what enzyme is the main player in RNA transcription
RNA polymerase II - binds to TATA
47
DNA polymerase III
in e.coli - primary enzyme for DNA replication (equivalent to DNA poly age in eukaryotes)
48
which RNA in eukaryotes transcribes mRNA
RNA poly II ( 1 synth rRNA, 3 synth tRNA and some rRNA)
49
differences in DNA polymerase and RNA polymerase (one MAIN one)
RNA does NOT proofread also doesnt need an RNA primer ... duh
50
antisense stranf vs sense strand terminology refers to
antisense is the template strand so antiparallel and complmentary and the sense strand --> is identica to the mRNA (exept it has thyamine - mRNA has uracil ) but it doest do anything during transcription- just gets pulled apart and seperated
51
is uracil or thymine heavier
thymine- bc it has one extra methyl group
52
affliction
something that causes pain or suffering
53
the first base transcribed from DNA to RNA is denoted?
+1 ( there is no zero) - TATA is usually around -25
54
what is mRNA called before it is processed?
hnRNA -the primary transcript
55
before hnRNA can leave the nucleous what has to happen
3 things so that it can survive the cytoplasm and interact with ribosome - poly A tail, 5' cap and intron splicing
56
introns
stay in the nucleus
57
what enzymes splice
snuRPs/ snRNA complex
58
whats the 5' cap
7-methylguanylt triphosphate cap - protect from degradation
59
poly A tail
like time bomb as sooon as it leaves the tail will start getting degraded so the longer the tail the better
60
what is still left at the end of hnRNA processing? why?
UTRs- untranslated regions of mRNA on both the 5' and 3' end - bc ribosome initiated translation at the start codon and end at stop - roles in stability, translation ect..
61
where does translation get its energy from
GTP is required for each step: initiation, elongation and temination
62
eukaryotes subunits
40S + 60S = 80S
63
prokaryotes subunits
50S + 30S = 70S
64
where does translation occur
in the cytoplasm
65
in pro where does small ribosome bind
Shine-Dalgarno sequence which is in the 5' UTR
66
in euk where does the small ribosome bind
to the 5' cap
67
RNA --> protein - what way does ribosome read the mRNA? how does this ocmpare to the reading of RNA polymerase
ribosome reads 5' to 3' ---> synth protein from N to C terminal whereas NA poly and DNA poly READ 3' to 5' bc they synthesize 5' to 3'
68
whats in the A site
the next amino acid to be added (determined by the mRNA codon in the A site bottom - order is APE
69
whats in the P site
the tRNA with the growing peptide chain also where the first methionine binds the polypeptide chain is passed from P to A with peptidyl transferase (GTP)
70
when ribosome comes across a stop codon
a release factor binds to A site -- this causes a water molecule to be added chain to hydrolyze the chain from tRNA
71
prenylation
adding lipid groups to proteins
72
Alternative Splicing vs. Monocistronic
so eukarytes are monocisronic meaning that one gen codes for one primary hnRNA under control of one promotor - however alternative splicing can cause many different ISOFORMS of that protein to come about whereas prokaryotes have many genes under the contro of one promotore (lac) byut dont have mRNA proccessing
73
does prokaryotic mRNA get processed
In prokaryotes, there is a little or no processing of mRNA transcripts. Prokaryotic mRNA is degraded very rapidly from 5′ end. Therefore, to rescue from degradation it is translated before being finally transcribed.
74
operator site
non-transcribable region of DNA that a repressor protein can bind
75
promotor region
for RNA polymerase to bind
76
reguator gene
code from protein known as repressor
77
inducible system
repressor bound tight to operator, negative control need an inducer to remove the roadblock
78
example of an inducable system
lac operon --> repressor is bound but lactose can act as an inducer and remove the roadblock with help of CAP ( a TF)
79
CAP
is a TF used in e.coli, low glucose- need to use diff fuel source, low glucose= high cAMP which binds to CAP- change shape and it can now bind to the promoter region of gene- further increase transcription of lactase genes CAP binding increases transcription - this is called positive control
80
repressible system
usually always on, but when corepressor binds, the repressor binds to the operator and stops transcription - Trp operon when tryptophan is high it acts as a corepressor and a binds to repressor causing it to bind to operant site and thus turns off cells own supply of tryptophan
81
histone acetylases
coactiators open up DNA bc they add an acetyl group to lysine whihc decreases positive charge on protein- lessens its attraction to DNA so it open up
82
histone deacetylases
deactivate DNA (close it up)
83
DNA methylation
silencing | during development - methylation plays an important role in silencing genes that are no longer needed

UWorld wrong answers - but that ill get right next time, YAY! (20 decks)

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