Biochem :( Flashcards
Elevated plasma porphyrins and photosensitivity
Deficiency in uroporphyrinogen decarboxylase
Photosensitivity means it is a late step problem
C-Jun
N-myc
Transcription factors that bind DNA
Northern Blot
RNA
uses ssDNA or ssRNA to probe
Used to assess gene expression
Southern blot
DNA
Paternity test
Western blot
Protein
Ab probe
Soutwestern blot
DNA-binding protein
Double stranded DNA probe
Transcription factors
Tumor Lysis syndrome
During chemo
Prevention: hydration and hypouricemic agents (allopurinol)
Heterochromatin
Methyl chromatin and non-acetylated histones
Condensed and transcriptionally inactive
Common reducing sugar in urine
Deficient fruktoinase
MAP kinase
GTP
Lynch syndrome
- NT mismatch repair defect
2. colon adenomatous polyps
Orotic acid in urine
Deficient ornithine transcarbamoylase
tx: uridine (inhibits CPS synthase II to prevent hyperammonia)
Deficiency in Dihydrobiopterin reductase
Atypical PKU
decreased levels of dopamine
Increased levels prolactin
Sx do not improved with restricted phenylalanine
Maple sugar odor in child
Alpha ketoacid dehydrogenase defect
Cannot break down branched chain amino acids (leucine, isoleucine, valine)
Glucose 6 phosphate dehydrogenase def (G6PD def)
X linked
hemolytic anemia during oxidative stress
common in africal and mediterranean
fava beans can induce hemolytic anemia
Alpha helix/beta sheets
Mediated via secondary structure (H bonds)
Hypoglycemia with fasting and low ketones
Impaired beta oxidation
commonly acetyl coA dehydrogenase def (catalyzes first step in beta oxidation)
Green bruise
Heme oxygenase turns heme into biliveriden
Primase
DNA dependent RNA polymerase that incorporates mall RNA primers into replicating DNA
Often with uracil
How much leptin is produced by adipocytes?
proportional to quantity of fat stored
Ketogenic AA
- Lysine
- Leucine
Would increase lactate in pts suffering from PDH deficiency
High levels arginine
Arginase deficiency (urea cycle)
Def of sphingomyelinase
Neimann pick disase
- AR
- mental retardation, splenomegaly, cherry red spot on macula
- foam cells in bone marrow
- death by 3
Sphingomyelin accumulates
Tay Sachs
Beta hexosaminidase def
GM2 accumulation
cherry red spot
ashkenazi jews
Dietary fructose
- fastest metabolized
- phosphorylated in liver to F-1-P
- rapidly metabolized because it bypasses PFK-1 (rate limiting step of glycoysis)
Rate limiting step of glycolysis
PFK-1
Streptomycin
inhibits the initiation of protein synthesis by binding to and distorting 30s ribosomal subunit of prokaryotes
Collagen production
hydroxylation of proline and lysin in RER (vit C cofactor)
Procollagen
glycosylation of pro alpha chain lysine residues (in RER)
triple helix with 3 alpha chains
Tropocollagen
c terminal pro peptide removal
collagen fibrils
cross linking bycovalent lysine-hydroxyl lysine cross links by lysyl oxidase (requires copper)
Immediate source of nitrogen for urea
aspartate
G6PDH deficiency
Similar to deficiency in glutathione reductase
Increase RBC oxidation damage leading to hemolytic anemia
Precursor to NAD+ coenzyme
tryptophan
Niacin def
Pellagra
dermatitis, dementia, diarrhea
Gene Enhancers are located
variable location
Promoters are located
25-7 bases upstream
TATA box
promoter
bings TF and RNA pol II during initiation
Poly AAA
3’ tail NOT transcribed by DNA template
HOMEOBOX gene
code for proteins such as transcription regulators
DNA pol I
5’-3’ exonuclease can remove RNA primer
5’-3’ polymerase
3’-5’ exonuclease
Lupus antibodies
Splicesomal snRNPs
Aminoglycosides
bind 30s subunit and inhibit formation of initiation complex and mixread RNA
Chloramphenicol
binds 50s
inhibits peptidyl transferase
Macrolides
bind 50s
prevent release of uncharge RNA
Tetracyclines
binds 30s
blocks aminoactyl tRNA attachment at A site
Stop codon is recognized by
releasing factor
Mischarged tRNA
reads correct codon but inserts wrong AA
Fetal Hb
2alpha 2gamma
poor interaction with 2,3-BPG
Binds oxygen with higher affinity
Galactosemia
- galactose 1-phosphage uridyl transferased deficiency
2. galactose kinase deficiency
galactose-1-phosphate uridyl transferase
- vomit
- mental retardation
- lethargy
- failure to thrive
- cataracts
AR
die within first few months of life
Galactose kinase deficiency
- mild galactosemia
- cataracts early in life (aldose reductase)
- mild form of galactosemia (does not cause death)