Biochemistry First Aid- Metabolism Part 2 (107-118) Flashcards
galactokinase deficiency is fairly mild, but what symptoms may occur?
may initially present as failure to track objects or to show social smile; galactose in blood and urine, infantile cataracts
classic galactosemia results from what enzyme deficiency
galactose-1-phosphate uridyltransferase
what are the symptoms of galactosemia
failure to thrive, infantile cataracts (galacticol accumulates in the lens of the eye), jaundice, hepatomegaly, intellectual disability
what’s the treatment for classic galactosemia
exclude galactose and lactose (galactose + glucose) from diet
what microbiologic complication can arise in patients with classic galactosemia
E. coli neonatal sepsis
_______ is converted to sorbitol via ___________
glucose is converted to sorbitol via aldose reductase
sorbitol is converted to ___________ via __________
sorbitol is converted to fructose via sorbitol dehydrogenase
what tissues have insufficient sorbitol dehydrogenase leading to risk of disease in hyperglycemic states
schwann cells (peripheral neuropathy), retina, kidney, lens
in addition to converting glucose to sorbitol, aldose reductase also converts galactose to ___________
galacticol
lactose intolerance is caused by deficiency of what enzyme
lactase
what are the three kinds of lactase deficiency
primary (loss of lactase persistence allele as an adult), secondary (loss of brush border due to gastroenteritis), congenital (defective gene from birth)
what would be the stool and breath test findings in someone with lactase deficiency
stool has low pH, breath test shows high hydrogen content with lactose tolerance test
what are the symptoms of lactase deficiency and how is it treated
Sx: flatulence, bloating, cramping, osmotic diarrhea
Tx: avoid dairy, lactase pills, lactose-free milk
what enantiomer of amino acids are found in proteins
L-form
name the essential amino acids and separate them by glucogenic, glucogenic/ketogenic, and ketogenic
glucogenic: methionine, valine, histidine
both: isoleucine, phenylalanine, threonine, tryptophan
ketogenic: leucine and lysine
name the acidic amino acids
aspartic acid and glutamic acid
name the basic amino acids and specify which is most basic
arginine, lysine, histidine
arginine is most basic
which basic amino acid has no charge at body pH
histidine
which amino acids are required during periods of growth
arginine and histidine
which amino acids are predominant in histones
arginine and lysine
which enzyme converts NH3 and CO2 to carbamoyl phosphate in the urea cycle
carbamoyl phosphate synthetase I
name the intermediates of the urea cycle (starting with aspartate entry into the cycle)
aspartate –> argininosuccinate –> arginine –> ornithine + carbamoyl phosphate –> citrulline
how is ammonia from amino acids sent off from the muscle
step 1: ammonia from amino acids gets transferred to alpha-ketoglutarate to make glutamate (generating alpha keto acids in the process);
step2: glutamate transfers ammonia to pyruvate to make alanine (regenerating alpha-ketoglutarate in the process)
explain the alanine cycle
function: the alanine cycle transports ammonia between muscle and liver;
1. alanine in muscle carries NH3 to liver,
2. alanine gets converted to pyruvate, which becomes glucose
3. glucose moves back to muscle
4. glucose gets converted to pyruvate
5. in the muscle pyruvate is aminated to form alanine