Flashcards in Things I just can't seem to remember for STEP 1 Deck (74)
What structures form the Hesselbach's triangle
- Inferior epigastric artery
- Inguinal ligament
Lateral border of rectus abdomens
* Direct inguinal hernias
Medial inferior gastric artery
Amino acids necessary for Purine
Enzyme that converts ribonucleotides to deoxyribonucleotides
What is the rate limiting step of Pyrimidine base produciton
Carbamoyl Phosphate synthetase II
( requires 2ATP molecules)
What is the rate limiting enzyme of purine synthesis
Glutamine phosphoribosylpyrophosphate (PRPP) amidotransferase
DNA Polymerase in prokaryotes and their function
DNA polymerase III: leading and lagging strand elongation
- exonuclease activity proof reads (3'-5')
DNA polymerase I: excises RNA primer and replaces it with DNA
-excises RNA primer in a 5'-3'
DNA polymerases in Eukaryotes and their functions
DNA polymerase alpha: puts down RNA primer and makes okazaki fragments on lagging strand
DNA polymerase beta: DNA repair
DNA polymerase delta: leading strand
DNA polymerase gamma: mitochondrial DNA
mutation in DNA is transversion vs. transition
Transition -- purine to purine (or pyrimidine to pyrimidine)
Transversion -- purine to pyrimidine (vice versa)
mutation of helicase
* blocks DNA replication and repair
- hypersensitivity to sunlight
-preceptibility to cancers (leukemias)
What is the start codon and who are the stop codons
Start codon: AUG -- Methionine
UGA -- U Go Away
UAA-- U Are Away
UAG--- U Are Gone
Causes of meningitis in Newborn (6months)
Group B strep
Causes of meningitis in Children (6m-6years)
H. influenza type B
Causes of meningitis 6-60years old
N. meningitidis ( #1 in teens)
Causes of meningitis 60+ years old
Gram negative rods
What is the enzyme that attaches an amino acid to the tRNA
aminoacyl- tRNA synthetase
_attaches amino acid to 3' CCA sequence
"Can Carry Amino"
If charged an incorrect amino acid, bond is hydrolyzed and aminoacyl- tRNA synthetase will put on the correct one
Triad of tuberous sclerosis
seizures, intellectual disability, angiofibromas
Enzyme missing in I-cell disease
N-acetylglucosaminyl-1-phosphotransferase --- failure of golgi to phosphorylate mannose 6 phosphate. Proteins are secreted rather than going to lysosomes
- course facial features, clouded corneas, restricted joint movements, and high plasma levels of lysosomal enzymes.
X linked recessive connective tissue disease caused by impaired copper absorption and transport
Defective Menkes protein : ATP7A (recall 7B is Wilson's disease GI chapter)
Biochemical cause of Marfan?
defect in Fibrillin -- a glycoprotein made by fibroblasts that forms a sheath around elastin
What bug causes Q fever?
Why can't muscle cells completely break down glycogen? (glycogenolysis)
Muscle cells do not posses Glucose -6-phosphatase. This does not mean that muscle cells cannot undergo gluconeogenesis. They can get up to Glucose-6 phosphate and then use that in glycolysis/ energy but they cannot distribute glucose to other organisms ( like the liver can)
What enzyme catalyzes the rate limiting step in carbohydrate digestion?
oligosaccharide hydrolases -- found on intestinal brush border
Describe Pyruvate Dehydrogenase Complex
3. treatment if congenital
4. can it be acquired?
X- linked build up of pyruvate that gets shunted to Lactate and Alanine
neurological defects, lactic acidosis, high serum alanine starting in infancy
Increase intake of ketogenic nutrients ( high fats, lysine, leucine)
Yes, arsenic poisoning, thiamine deficiency (alcoholics)
What causes Phenylketonuria and what are the physical findings?
Loss of phenylalanine hydroxylase or it's co-factor tetrahydrobiopterin (BH4)
Excess phenylalanine-- excess phenylketones in urine
+ neurotoxic effect
Findings: Intellectual disability, growth retardation, seizures, fair skin (melanin is in phenylalanine pathway), eczema, musty body odor
Tx: decrease phenylalanine and increase tyrosine in diet, tetrahjydrobiopterin supplementation
AVOID ARTIFICIAL SWEETENER ASPARTAME
What is the name of the disease that is deficient in homogentisate oxidase?
enzyme is in degenerative pathway of tyrosine to fumarate --> pigment forming homogentisic acid accumulates in tissues.
Findings: dark connective tissue, brown pigment sclerae, urine turns black on prolonged exposure to air. May have debilitating arthralgia (homogentisic acid toxic to cartilage)
What is maple syrup urine disease
-who is involved?
Blocked degradation of branched amino acids due to decrease in alpha-ketoacid dehydrogenase (B1)
" I Love Vermont maple syrup"
Causes severe CNS defects, intellectual disability, and death
Urine smells like maple syrup
Tx: restriction of isoleucine, leucine, and valine in diet, and thiamine supplementation
What is hartnup disease?
- deficient mechanism?
- what do you see clinically?
Autosomal Recessive defect of transporter in intestine and kidneys
-deficiency of neutral amino acids transporters in proximal renal tubular cells and enterocytes
-deficiency of neutral AAs -- tryptophan
- without tryptophan you can't make Niacin
- without Niacin you get Pellagra
- dermatitis, diarrhea, dementia
-tx: high protein diet and nicotic acid
What type of infection is a patient with IL-12 receptor deficiency at highest risk for developing?
What are the toxins produced by Strep pyrogens?
Hemoysis on blood agar, oxygen labile
Streptolysin S: oxygen stable
Streptococcal pyrogenic exotoxins: A, B, C
-- erythrogenic toxins: red rash of scarlet fever
-- B : necrotising fascitus
-- can work as super antigens TSS