FA 2016 pg 48-51 Biochem Flashcards
Histones are rich in which 2 amino acids
arginine & Lysine
what is an Heterochromatin and whats an example
condensed and appears dark on EM
transcriptionally inactive
barr bodies are a type of heterochromatin
what s Euchromatin
less condensed & transcriptionally active
Lighter on EM
which nucleotide is the template strands undergo methylation
cytosine & adenine
methylation represses transcription T or F
T
acetylation allows transcription T or F
T
what is a nucleoside made up off
Base and sugar (ribose)
what is a nucleotide made up off
Base, sugar and phosphate
how is the phosphate group linked in a nucleotide and in what direction
using phosphodiesterase bond at 3’-5’ direction
what amino acid is necessary for the formation of purine synthesis
Glycine Aspartate & Glutamate
what are the starting products of pyrimidine synthesis
glutamate and Co2
caramel phosphate to orotic acid is blocked by what drug
leflunomide
inhibits dhydroorotate dehydrogenase what drug?
Leflunomide
a 3 year old boy is brought to the ER for swollen hands and feet. The boys older brother died at the age of 7 from pneumonia. Physical examination shows a wedge shape infracts in the spleen, what is the MOA for the medication to treat this boy.
Hydroxyurea (inhibit ribonucleotide reductase)
diagnosis sickle cell
what three drugs inhibit dihydrofolate reductase
methotrexate, trimethoprim and pyrimethamine
what is the antidote to treat the drug that inhibit thymidylate synthase
Uridine used for 5FU toxicity
what other drug has the same mechanism of action as Mycophenolate
RIbavirin (block InosineMono Phosphate dehydrogenase)
what two drugs inhibit de novo purine synthesis
azathioprine and 6MP
what are the findings in Lesch Nyhan syndrome
intellectual disability, self-mutilation, aggression, hyperuricemia, gout, dystonia
DNA replication is conservative T or F
F (it is semiconservative involving both continuous and discontinuous synthesis)
what specific sequence is found on promoters and origin of replication
AT-Rich sequence
deficiency in the protein that unwinds DNA template at replication fork is called?
Bloom syndrome (deficiency of Helicase)
what prevents strands from re-annealing
single stranded binding proteins
what are the functions of DNA polymerase 3
has a 5’-3’ synthesis & 3’-5’ exonuclease proofreading activity
what enzyme degrades RNA primer
DNA polymerase 1
what enzyme makes RNA primer
primase
what enzyme has a 5’-3’ exonuclease activity
DNA polymerase 1
A RNA-Dependent DNA polymerase that adds DNA to 3’end of chromosomes to prevent loss of genetic material is called———
telomerase (eukaryote only)
muscle weakness and pain after intense exercise and no ketones
MCAD deficiency (presence of dicarboxylic acid is diagnostic)
what enzyme deficiency is associated with sudden infant death syndrome
MCAD
doll like faces, protruding tongue hepatomegaly and hyperuricemia refers to what disease?
Von Gierke (def of glucose-6 phosphatase)
AR disorder that is due to deficiency of neutral amino acids
Hartnups disease
What G.I Pathology is associated with CPG methylation
serrated polyps
what are the symptoms of Bloom syndrome
No helicase cause short stature, rash from sun, cafe au lait, leukemia, lymphoma
what is the triad of SCID
recurrent infection, diarrhea and failure to thrive
what is responsible for joining okazaki fragment together
DNA ligase
