Biochemistry Flashcards
DNA condensed ?
Chromatin
What make the Nucleosome?
Histone + DNA
What aminoácido have the histone?
Lysine and arginine
What’s the structure that stabilize the chromatin?
H1
What’s te phase when DNA condenses to chromatin?
Mitosis
DNA + histone synthesis occur in..?
S phase
One nucleosome is made by.?
(H2A, H2B, H3, H4) x2
Witch chromatin is less condensed on EM?
Euchromatin
Which chromatin is darker on EM?
Heterochromatin
Which chromatin is high transcriptionally active?
Euchromatin
Which chromatin have high methylation?
Heterochromatin
What kind of chromatin are Barr bodies?
Heterochromatin
What does the methylation of DNA at CP6 islands do?
Represses transcription
What does the histone acetylation makes to DNA?
activate it
Nucleoside?
Base + deoxy ribose
Nucleotide?
Base + deoxy ribose +phosphate
Who’s the purines?
Adenine and guanidine
How many rings does purines have?
2
Who’s the pyrimidines?
Cytosine, uracil and thymine
How many rings does the pyrimidine have?
1
What does deamination of cytosine do?
Uracil
What does deamination of adenine do?
Guanine
Where you can found uracil?
RNA
Where you can found thymine?
DNA
How many bound are between guanine and cytosine?
3
How many bounds are between adenine and thymine/uracil?
2
What are the amino acids necessary for purines synthesis?
Glycine, aspartame, glutamine
What’s does methylation of uracil do?
Thymine
How works leflunomide?
Inhibits dihydroorate dehydrogenase
What does methotrexate do?
Inhibits dihydofolate reductase in humans
What does timethoprim do?
Inhibits dihydofolate reductase in batería
What does pyrimethpmine do?
Inhibits dihydofolate reductase in Protozoa
How works 5-fluoroucil?
Forms 5-F-dUMP which inhibits thymidylate synthase
What does 6-mercaptopurine do?
Inhibit de novo purine synthesis
What’s the prodrug of 6-mercaptopurine?
Azathiopine
How works mycophenolate/ribavirin ?
Inhibit inosine monophosphate dehydrogenase
What does hidroxyurea do?
Inhibits ribonucleotide reductase
Why is adenosine deaminase important?
Because is required or degradation of adenosine and deoxyadenosine.
What occurs In ADA deficiency?
^ dATP so the toxicity in lymphocytes.
Ada deficiency is response of what?
One o the major causes of autosomal recessive SCID
What is Lesh-nyhan syndrome?
A x-linked recessive syndrome with defective purines salvage due to absent HGPRT.
Whats HGPRT do?
Converts hipoxantyne to IMP and guanine to GMP
Findings of sx lesch-Nyhan ?
Hyperuricemia, gout, aggression, self mutilation, intellectual disability and dystonia.
Treatment of 1st line of Lesch-Nyhan sx?
Allopurinol
Treatment of 2nd line of Lesch-Nyhan sx?
Febuxostat
How does allopurinol/febuxostat works?
Inhibits xanthine oxidase (XO)
What’s the compose of the ornate sand in Lesch-Nyah’s sx?
Sodium urate crystals
When a purine is changed to a Purine, or a pyrimidine to pyrimidine what kind o mutation in DNA is?
Transition
Purine to pyrimidine or pyrimidine to purine is what kind o mutation?
Trans version
Nucleotide substitution but codes for same amino acid; often change in 3rd position of codon
Silent
Nuke o tide substitution resulting in early stop condone (UAG, UAA, UGA). Usually nonfunctional protein.
Nonsense
Nucleotide substitution resulting in changes amino aid
Missense
What kind of mutation in DNA is the Sickle cell disease?
Missense
What amino acid is substituted and by whom in DNA codon in sickle cell disease?
Glutamine x valine
Deletion or insertion of a number of nucleotides not divisible by 3, misreading of all nucleotides downstream.
Frameshift
Duchenne muscular dystrophy and tay-Sachs disease are..?
Frameshift mutations
