Nucleotides Flashcards
1
Q
Nucleotides
- what are they
- Purines
- Pyrimidines
- binding
A
- building block of nucleic acids
- adenine and guanine
- cytocine, thymine, uracil
- adenine to thymine with double bond, cytosine to guanine with triple bond
2
Q
Chromatin
- Hetero
- Eu
A
- tight, resting phase
- loose, cell division
3
Q
Tests for detection
- Southern Blot
- Northern Blot
- Western Blot
- Elisa
- PCR
A
- DNA
- RNA
- Protein
- antibodies
amplifies small amount of DNA or RNA
4
Q
- Lesch nyhan
- adenosine deaminase def
- xanthing oxidase def
- hereditary orotic aciduros
A
NEED TO KNOW
5
Q
Purine Synthesis DeNovo
- pathway
- IMP goes into
- finished products
A
- R5P + PRPP synthetase -> PRPP + pyrophosphate aminotransferase -> 5 phosphoribosykamine -»» IMP
- IMP + adenylosuccinate synthase-> adenylosuccinate + adenylosuccinate lyase-> AMP and IMP+ IMP dehydrolase -> XMP + XMP glutamine amidotransferase -> GMP
- ATP and GTP
6
Q
Lesch Nyhan Syndrome
- genetics
- what is it, why
- normal pathway
- sxs
A
- x linked
- accumulation of Uric Acid bc of HGPRT doesn’t work
- Cannot recycle Hypoxanthine and guanine into IMP and GMP
- crystals in diaper, poor muscle tone, irritability and self mutilating behavior
7
Q
Gout
- what is it
- mutation
- findings
- acute management
- chronic management
A
- hyperurecemia causing crystal formation in joints
- activating mutation of PRPP causing increase de novo production which will increase the amount that will be broken down
- needle shaped negatively birefringent crystals
- NSAID and colcichine os indomethacin w/ pts who have renal problem
- allopurinol
8
Q
SCID
- what is it
- caused by
- prognosis
- tx
A
- severe combined immune deficiency
- adenosine deaminase is missing -> dATP levels rise -> shuts down RNR -> shut down DNA synthesis -> shuts down rapidly dividing cells in body
- 2 yrs old, death from infection
- bone marrow transplant
9
Q
Xanthine Oxidsae Def
- what happens, how
- sxs
- tx
A
- xanthine accumulation, because guanosine and xanthosine can still be broken down into xanthine but unable to break down into uric acid w/o XO
- stone formation and kidney failure
- lots of fluids to prevent stone formation and avoid foods high in
10
Q
Xeroderma Pimentosum
- what is it
- genetics
- epi
- sxs
- sequlae
- prognosis
A
- inability to repair damage caused by UV light
- AR
- children
- photo sensitivity, hyper pigmentation, pokyloderma (hyper or hypo pigmentation, thin skin, telangectasia)
- prone to develop skin CA
- will die from squamous cell CA or melanoma by 20 yrs old)
11
Q
Orotic Aciduria
- what is it
- mutation
- sxs
- tx
A
- excessive excretion of orotic acid bc of UMP synthetase
- AR
- white crystals in diaper, megaloblastic anemia, and inhibits RNA/DNA synthesis
- supplement CMP and UMP to provide neg feedback and decrease orotic acid present
12
Q
Pyrimidine 5 nucleotide deficiency
- mutation
- what is it
- causes
A
- AR disorder
- needed for pyrimidine metabolism to turn nucleotide into nucleoside but not working so have build up of pyrimidines
- hemolytic anemia
13
Q
Damage to DNA Excision enzymes
- Thymine dimers
- Cytosine Dimers
- Apurination or aprimidation
- mimastched
A
- excision
- AP endonuc
- AP endonuc
- mismatch repair
14
Q
Histones
- purpose
-
A
- package DNA
15
Q
DNA helices
- A
- B
- Z
A
- right handed w/ 10 bp to turn
- right handed w/ 11 bp to turn
- left handed w/ 12 bp to turn