Cells

Question 1

Xeroderma pigmentosum

Answer 1

They have an excision endonuclease (excinuclease) deficiency
This enzime target a thymine dimers damage cause by a UV radiation

Is autosomal recessive disorder

Question 2

Who fix the thymine dimers damage?

Answer 2

DNA polymerase

DNA ligase

Question 3

Mutation on one of this two genes hMSH2 and hMLH1 what cause?

Answer 3

Lynch syndrome or hereditary nonpolyposis colorectal cancer ( HNPCC)

Cause by a DNA replication errors

Is caused by DNA mismatch

Question 4

Who prevents a cell with damaged DNA from entering the S phases?

And how they prevents that?

Answer 4

P53

Inducing the apoptosis

Question 5

Inactivation or deletion from P53 are associated whit ?

Answer 5

Li fraumeni syndrome and others solid tumor

Question 6

What is ATM?

Answer 6

Encodes a kinase essential for P53 activity.

Is inactivated in ataxia telangiectasia, characterized by hypersensitivity to x ray and predisposition to lymphomas

Question 7

What cause lych syndrome in the chromosomes?

Answer 7

Microsatellite instability

Can produce a Broke’s chromosome

Question 8

Purines

Answer 8

PURe As Gold
Purines Adenine Guanine

Purines have 2 rings
NH2 - adenine

Question 9

Pyrimidines

Answer 9

CUT the PY (pie)
C- cytosine
U- uracil. RNA
T- thymine. DNA

Have two rings

Question 10

What is a nucleoside?

Answer 10

Base + sugar

Question 11

What is a Nucleotide?

Answer 11

Base + sugar + phosphate

Question 12

What inactivate the shiga’s toxin or verotoxim shiga-like toxin?

Answer 12

Inactivate the 28 s RNA in the 60s subunit

Question 13

What is the consequence of 28s rna in 60s subunit inactivate?

Answer 13

Avoid the synthesis of protein and the patient die

Question 14

Every gene has ?

Answer 14

He’s own promoter and the DNA polymerase recognizes every promoters

Question 15

Alternative splicing

Answer 15

The production of two protein from one gene

Question 16

Why we have more proteins in their sales that gene in the chromosome

Answer 16

Because the alternative Splicing

Question 17

Why the iG’s have the same protein but different function

Answer 17

Because the alternative Splicing

Question 18

Example for alternative splicing

Answer 18

Dopamine receptors D1 D2 D3

The membrane igG and secreted iGg

Question 19

Example of nonsense mutation

Answer 19

Hemophilia—> deficiency in F VIII

Question 20

What it’s the mean of nonsense mutation?

Answer 20

A nucleotide substitution resulting in early stop codon (UAG, UAA, UGA)

Usually results in nonfunctional protein

Question 21

Frameshift mutation

Answer 21

It’s a deletion or insertion of a number of nucleotides NOT DIVISIBLE BY 3

Question 22

Example of frameshift mutation

Answer 22

Duchenne muscular dystrophy

Deficiency —-> dystrophin

Question 23

Insertion of 4 nucleotides

Answer 23

Tay Sachs diseases

deficiency enzyme —>Hexoseminidose A

Question 24

What it’s a codon?

How many codons we have ?

Answer 24

It’s a triplete if nucleotides

64

Question 25

How many encodes codon we have ?

Why if we have 64 codons ?

Answer 25

61
Because 3 of this codon are stops codons
UAA UAG UGA

Question 26

Trinucleotides repeat expansions

mention the Pathologys

Answer 26

1) huntignton diseases
2) fragile X chromosome
3) fredeich’s ataxia
4) spinoblubar muscular dystrophy
5) mio tonic syndrome

Question 27

The name of the trinucleotide repeat expansion in Huntington diseases

Answer 27

CAG —> glutamine

5 repeats

Question 28

What it’s the anticipation’s phenomenon

Answer 28

The number of repeats often increases with the successive generations and correlates with increasing severity and decreasing age of onset

Question 29

Missense mutation

Answer 29

Nucleotide substitution resulting in changed amino acid

Question 30

Example of missense mutation

Answer 30

Sickle cells anemia

Substitution of glutamic acid for valine