Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Bio/Biochem > genetics > Flashcards

genetics Flashcards

(71 cards)

Start Studying
1
Q

purines and pyrimidines

A

purines = AG (2 bonds, 2 rings). pyrimidines = CT (3 bonds, 1 ring)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

telomeres

A

only in eukaryotes, reads TTAGGG…

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

stop codons

A

UAA, UGA, UAG

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

nucleotide structure

A

triphosphate on 5’ of sugar. deoxy on 2’. nitrogenous base on 1’. Free hydroxyl end on 3’.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

point mutation

A

single substitution of NT. May result in missense, nonsense, or silent mutation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

frameshift mutation

A

very serious. NTs inserted or deleted not in multiple of 3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

UV ray mutation

A

causes pyrimidines to fuse into dimer. Distorts helix backbone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

X ray mutation

A

can break covalent bonds, such as break backbone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

intrastrand and interstrand crosslinking

A

form of endogenous DNA damage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

if transposon is put in intergenic region

A

no effect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

if transposon put in coding region

A

mutation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

mismatch repair pathway

A

during or soon after replication to correct a single mismatched bp. Identify parent strand by its methylation to correct daughter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

NT excision repair

A

can occur anytime; replace the bad base with correct one

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

homologous recombination

A

must occur BEFORE replication, you use the other sister chromatid as a template to correct chromosomal DSBs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

non homology end joining

A

can occur anytime; just use ligase to join broken ends of a chromosome (this is the option before S phase when there’s no sister chromatid as reference)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

theta replication

A

occurs in prokaryotes’ circular DNA, beginning at a single Ori. proks have 5 DNA polymerases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

DNA pol III

A

very fast. It is the main replicase enzyme. No repair function.
Also has 3’ to 5’ exonuclease activity (when it backs up a NT and lops it off if wrong. This is called the proofreading function that can ONLY occur during replication)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

DNA pol I

A

slower than pol III. Like III, it has 3’ to 5’ exonuclease activity where it can proofread too. Unlike III, it can remove RNA primers in 5’ to 3’ direction. it performs excision repair

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

telomerase

A

extends telomeres (reverse transcriptase ability because it copies its RNA template to make DNA)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

DNA pol II

A

backup for DNA pol III. Also possesses proofreading function and also has repair mechanisms.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

DNA pol IV and V

A

quite error prone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

hnRNA

A

heterogeneous nuclear RNA. Large pre-mRNAs that must be further processed before entering cytoplasm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

siRNA

A

short interfering RNA. It is double stranded and exogenous, taken up by cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

miRNA

A

micro RNA, single stranded and endogenous

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Compare prok and euk transcription
Prok: translation occurs simultaneously with transcription; no processing of mRNA, only 1 RNA pol. No introns, no splicing. Euk: translation occurs in cytoplasm; mRNA needs to be mature, 3 RNA pol types
26
Poly vs monocistronic
In prokaryotes, many proteins can come from 1 mRNA transcript
27
aminoacyl tRNA synthetase
matches tRNA to its amino acid. Takes 2 ATP.
28
Wobble theory
though the first 2 NTs of the codon pair correctly, the 3rd has some leeway, permitting the same tRNA to match with multiple codons that vary in the 3rd letter. This reduces number of tRNA types needed
29
Translation energy requirements
takes 4ATP per 1 amino acid
30
release factor
binds to stop codon to release growing peptide from ribosome
31
Shine-Dalgarno sequence
sequence in mRNA, upstream of AUG, that helps find and bind ribosome. ONLY PROKARYOTES
32
photoreactivation
visible light can recruit enzymes to repair pyrimidine dimer mutations formed by UV
33
gyrases
only exist in prokaryotes; they maintain the helix coil shape
34
splicing
hnRNA -> mRNA. Occurs in nucleus.
35
metacentric
p and q arms equal in length
36
submetacentric
p and q arms almost equal; q still longer
37
acrocentric
p arms VERY VERY short
38
Kozak sequence
sequence in eukaryotic mRNA (not prok) by which ribosomes can recognize it. They also recognize 5' cap
39
telocentric
p arms shorter even than acrocentric; barely there
40
2 DNA strand types?
``` coding = sense template = antisense = the one being 'read' by RNA pol ```
41
heterochromatin
has more histones, very compact. mostly noncoding regions; euchromatin: more often transcribed
42
kinetochores
multi protein complexes that attach spindle fibers (of mitosis) to the centromeres of chromosomes
43
types of genomic variation
single nucleotide polymorphisms, copy-number variations, and tandem repeats (which are rich in heterochromatin, centromeres, telomeres)
44
SSBPs
bind to exposed DNA to prevent reannealing
45
nucleophile
the 3' hydroxyl during replication is the nucleophile
46
ethidium bromide
a mutagen that inserts itself between bp (intercalating) thus causing errors in replication
47
inversion
chromosomal mutation where a segment is flipped
48
amplification
chromosomal mutation where segment is duplicated
49
translocation
chromosomal mutation where segment is moved to another chromosome altogether
50
transposons
all contain a gene coding for transposase (that has cut and paste activity) IS element - simplest type; merely transposase flanked by repeats Complex transposon - IS element followed by genes Composite transposon - central region flanked by IS elements
51
hemizygous
when there is only one gene copy in a diploid organism. Quite dangerous, because having 2 copies protects from mutations
52
haploinsufficiency
diploid organism has only a single functional copy of a gene
53
ncRNA
non coding RNA includes tRNA and rRNA. Also a type call long ncRNAs that control basal transcription level by regulating initiation complex assembly. Also work on post transcriptional regulation and have a function in X-inactivation
54
rRNA
some rRNA serves a catalytic function, thus called RIBOZYMES
55
snRNA
associate with proteins to form snRNP which do splicing. They also regulate transcription factors and maintain telomeres
56
miRNA and siRNA
both bind specific mRNA to serve as post transcriptional regulation
57
piRNA
PIWI-interacting RNA are single stranded and short. they work with the PIWI protein class to prevent transposon movement
58
Pribnow box
a sequence in the bacterial promoter region (prok only) which is recognized by holoenzyme component of RNA pol
59
RNA pol I
makes most rRNA
60
RNA pol II
makes most hnRNA -> mRNA. Remember that transcription is MORE ERROR PRONE than replication
61
RNA pol III
makes tRNA, siRNA, miRNA, and certain rRNA
62
steps of translation
1. amino acid + ATP --> aminoacyl AMP + PPi 2. cleaving of PPi is extremely favored. this provides energy for tRNA loading (unfavourable). 3. tRNA loading is where aminoacyl AMP and tRNA become aminoacyl-tRNA, with the AMP discarded
63
aminoacyl tRNA synthetase enzymes
AT LEAST one for each amino acid type
64
eIF proteins
essential to initiate translation. One binds the smaller ribosome subunit, another binds the 5' mG cap of mRNA
65
cap-independent translation
long believed that euk could only translate start at the 5' cap, sometimes they begin in the middle of the transcript
66
where does each process occur?
transcription, splicing, polyadenylation, 5' cap adding = nucleus translation = cytoplasm
67
lac operon
P region - promoter site on DNA O region - operator site to which the lac repressor binds Z gene - codes for beta galactosidase, which digests lactose Y gene - codes for permease, so lactose may enter A gene - transacetylase, not strictly required for lactose metabolism crp gene - located elsewhere, codes for CAP, the glucose-dependent promoter protein I gene - also elsewhere, codes for Lac repressor protein. The repressor typically sits on the O region, blocking transcription, till binding a lactose makes it fall off
68
trp operon
for making tryptophan | trpR gene - codes for repressor. The repressor binds trp when present and in turn turns the operon off
69
post transcriptional control
miRNAs and siRNAs can inactivate mRNA cells also monitor quality of mRNA and degrade defective ones mRNA is also transported to correct location in cell BEFORE translated
70
post translational modification
chaperones fold proteins covalent modification (functional groups added, like sugars, phosphates, etc) cleavage
71
formyl-methionine
only used by prok; euk have regular methionine

Bio/Biochem (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions