Biochem Flashcards
What’s the rate limiting rxn in chol synth?
HMG Co reductase
Findings in PKU?
- mousy odor
- tyrosine missing (must be supplied in diet - can diagnose by amniocentesis and finding the abnormal gene)
- eliminate phenylalanine from diet (Nutrasweet is aspartate and phenylalanine so cannot use it)
I cell disease
inability to phosphorylate the mannose residues of potential lysosomal enzymes, hence they cannot be taken up by the lysosomes to degrade complex substrates
Number of lgucoses necessary to build palmitic acid a 16 carbon compound
4 glucoses - each glucose run producing 2 acetyl coA, the latter containing 2 carbons each
Insulin lack in DKA does what to glycolysis, glycogenesis, fatty acid synthesis and storage of fat in adipose?
decreases
uncoupling agents (e.g. alcohol, salicylates)
produces brown fat from increaed heat from reactions trying to increase the generation of more protons to make ATP
Von Gierke’s
decreased glucose 6-phosphatease (glucoeogenic enzyme) with decrease in glucose (fasting hypoglycemia) and increase in glucose 6-phosphate with production of normal glycogen in the liver and kidneys
Stimulation tests with glucagon, fructose, etc cannot increase the glucose levels owing to the missing enzyme
Biochem processes in both cytosol and mito
- urea cycle
- heme synthesis
- gluconeogenesis
Female with pheochromocytoma. What dietary alteration?
probably dec phenylalanine (essential AA0 and tyrosine (not an essential AA) in the diet
pregnant female with PKU. What diet?
low in phenylalanine and high in tyrosine
avoid Nutrasweet since it contains aspartate and pehylalanine
Lesch Nyan
SXR with absent HGPRT, self-mutilation, hyperuricemia, mental retardation
Enzyme only in the liver
Has high Vm and high Km.
Not inhibited by glucose 6-phosphate
glucokinase
Enzyme in all tissues
Low Vm and low Km
Inhibited by Glucose 6 phosphate
Hexokinase
Also known as branched-chain ketoaciduria, is a disorder affecting the aliphatic or branched-chain amino acids.
Maple syrup urine disease
Breakdown of glycogen to glucose 6 phosphate and glycogen.
glycogenolysis
Locations (3) of glucose 6-phosphatase (gluconeogenic hormone)
What disease is it absent in?
- liver
- kidney
- intestinal epithelium (lesser extent than others
Vongierke’s disease
What do the carnitine and malate shuttles carry?
- carnitine - even chained fatty acids
2. malate - NADH
Functions of LDL (4)
- vit D synthesis
- other steroid synthesis
- cell membranes
- synthesis of bile salts/acids
Acetyl CoA uses
- how many times used in FA synthesis
- CH synthesis
- ketone body synthesis
purpose of urea cycle
eliminate ammonia
If epinephrine is given and only small branched chains are found, what deficiency is present?
debrancher deficiency
Origin of
- apolipoproteins 100
- apolipoproteins 48
- liver
2. intestine
what’s the rate limiting step in glycogenolysis?
glycogen phosphorylase
Why cant the liver use ketones for fuel?
the liver cannot activate acetoacetate in the mito, which requires succinyl CoA: acetoacetate CoA transferase (a thiotransferase enzyme) in order to convert AcAc into Acetoacetyl CoA
What disease? Absent mm phosphorylase; increase glycogen in mm; no increase in lactic acid after exercise
McArdles disease
If a pregnant woman is a beer drinker, what supplements does she need?
- Folate bc ETOH inc loss of folate in urine and stool which offsets amt of folate in beer
- pt should be taken off beer bc of fetal alcohol syndrome and would need folate
- Fe is NOT affected by beer drinking
- Insulin is the key hormone of the ___ state
2. Glucaon is a key hormone of the ___ state
- fed
2. fasting
What is involved in the transfer of dolichol (lipid) in the RER in the synthesis of O-linked glycosides?
mannose 6-phosphate
