Genetics - Lecture 4, 5, 6

Front 1

depurination is hydrolysis of ______ from ________.

What kind of drugs do this?

Back 1

depurination is hydrolysis of RIBOSE from a purine (A or G).

Alkylating drugs induce this.

Front 2

In _________, NH2 falls off of ________ and is replaced by a _______ group.

So _____ is replaced by ______.

Back 2

In deamination, NH2 falls off of CYTOSINE and is replaced by a carboxyl group.

So cytosine is replaced by URACIL.

Front 3

Does deamination occur spontaneously?

Back 3

yes. but chemicals make it deaminate faster.

Front 4

What kind of damage does UV radiation do to DNA?

Back 4

UV radiation causes formation of pyrimidine bases. (Especially Thymine dimers).

Front 5

Oxidation is the kind of damage to DNA caused by?

Back 5

ROS resulting from normal metabolism.

Front 6

Why is radiation so bad for DNA?

What repairs this?

Back 6

Radiation breaks the double strand creating reactive ends = rearrangements, inversions, translocations.
NON-HOMOLOGOUS END-JOINING PROTEINS

Front 7

What is the inheritance pattern of a PROTOONCOGENE?

What do protooncogenes do?

Back 7

AUTOSOMAL DOMINANT

Increase activity in cell growth

Front 8

What is the inheritance pattern of tumor supressor genes?

Back 8

recessive

Front 9

What seals the nicks in DNA repair? How does it get the energy for this?

Back 9

DNA Ligase seals the nicks - it uses ATP.

Front 10

What are two specific DNA repair pathways?

Back 10

Nucleotide Excision Repair (NER)

Mismatch Repair

Front 11

What removes the bad DNA in the NER pathway?

What disease did we study that is caused by problems with this pathway?

Back 11

helicase

XP

Front 12

What removes the bad DNA in the Mismatch repair pathway?

What disease that we studied is caused by problems in this pathway?

Back 12

exonuclease

Hereditary Non-Polyposis Colon Cancer

Front 13

What is the inheritance pattern of XP?

Why does uv radiation create problems for XP patients?

Back 13

Recessive

UV radiation hits the skin - causes formation of Thymine dimers and NER can't fix it.

Front 14

What inheritance pattern does a mutated MSH2 gene follow?

What does the gene do?

Back 14

mediates repair of mismatched bases.

autosomal dominant

Front 15

Which needs a primer, DNAP or RNAP?

Back 15

DNA Polymerase needs a primer.

Front 16

What do snRNA's do? Where are snRNA's found? Why?

These are an example of _______.

Back 16

They remove introns in pre-mRNA. In the NUCLEUS - because that's where pre-mRNA is found as an initial transcript of DNA.
SPLICEOSOMES

Front 17

What is an anticodon?

Back 17

found on tRNA (one the inferior loop) - it "reads" the mRNA codon bc it matches it.

Front 18

this kind of mutation changes a codon into a stop-codon specifically.

Back 18

nonsense mutation.

Front 19

this kind of mutation causes the insertion or deletion of a number of base pairs not divisible by 3.

Back 19

frameshift mutation

Front 20

this kind of mutation changes the identity of one AA to another.

Back 20

missense mutation

Front 21

B-Thalassemia cap site degradation by exonuclease is called what?

What is the result?

Back 21

Promoter Mutation - the gene never begins

Front 22

B-Thalessemia mutation point: what kind of mutations cause introns to not be removed like they should?

What is the result?

Back 22

splice site mutations - makes non-functional proteins

Front 23

B-Thalessemia mutation point: what mutation causes change to the AAUAAA site?

What is the result?

Back 23

Polyadenylation Signal mutation - makes the strands way too long bc they don't know to stop.

Front 24

What enzyme makes NTP out of NMP?

Does this require ATP?

What does that mean for AMP?

Back 24

Nucleotide Kinase = REQUIRES ATP

futile cycle for AMP

Front 25

What enzyme makes NMP?

Can bases cross the cell membrane?

Back 25

Nucleoside kinase

bases alone can cross cell membrane

Front 26

if you start with ribose-5-phosphate what enzyme do you use to make 5-phosphoriboxyl-1-pyrophosphate? (PRPP).

Back 26

PRPP syntheTase.

Front 27

what enzyme makes NMP's from PRPP?

How does it do this?

Back 27

NPRT (nucleotide phosporibosyl transferase).

It does this by removing the pyrophosphate and putting a base in its place.

Front 28

excess amp pathway.

Back 28

amp (PHOSPHATASE)-->Adenosine (ADENOSINE DEAMINASE) --> inosine (NUCLEOSIDE PHOSPHORYLASE) --> hypoxanthine

Front 29

what rxn does nucleoside phosphorylase catalyze?

how?

Back 29

inosine --> hypoxanthine

it removes the ribose backbone

inosine is the "nucleoside" and hypoxanthine is the "base".

Front 30

SCID is caused by what?

Back 30

deficiency in Adenosine Deaminase

Front 31

excess guanine pathway

Back 31

guanine (GUANASE)--> hypoxanthine (XANTHINE OXIDASE)--> xanthine (XANTHINE OXIDASE)-->uric acid

Front 32

what enzyme does allopurinol inhibit?

Back 32

xanthine oxidase

Front 33

what's a nucleotide precursor to ATP and GTP?

Back 33

IMP

Front 34

What enzyme lack/deficiency causes Lesch-Nyhan Syndrome?

What is the inheritance pattern of this disease?

Back 34

HGPRT

X-linked recessive

Front 35

Sx of Lesch-Nyhan Syndrome?

Back 35

Bad gout, mental retardation, spastic CP, self-mutilation

Front 36

what enzyme makes deoxyribonucleotides from ribonucleotides?

Back 36

ribonucleotide reductase

****ONLY WORKS ON NDP'S (not NMP'S)
(diphosphates only)

Front 37

what takes useless dUDP and makes it into DTMP?

in the presence of what coenzyme?

Back 37

Thymidylate Synthase

folate is the coenzyme

Front 38

how does 5-flourouracil work?

Back 38

irreversible inhibitor of Thymidylate Synthase.

dTMP never gets made from dUMP