biochemistry - amino acid catabolism Flashcards
organ which is main site of amino acid degredation
liver
where is urea formed
liver (not kidneys)
Urea Uric acid Creatinine Ammonium ion (NH4+) these are nitrogen-containing excretory molecules, which is the most important
urea - 80%
transamination of urea is when amino acid and ketoglutarate react forming keto acid and glutamic acid, what happens in the next step to synthesise urea
de-amination
glutamic acid reacts with NAD+ and H+, creates ketoglutarate and NADH + NH4+
aspartic acid then reacts with NADH + NH4+ to give urea
major carriers of nitrogen in blood to liver
alanine
glutamine
when amino is transferred to pyruvate, what does this give
alanine
how is glutamine produced
NH4+ adds to glutamate
via glutamine synthase
urea is synthesised in a complex series of reactions, including the urea cycle and the addition of Carbon from CO2, how is the nitrogen added
one nitrogen from free ammonium (cleaved from glutamine)
one given from aspartic acid
`degradation of carbon skeletons gives
metabolic intermediates which can be converted to glucose/ oxidised in TCA
other than degrading to acetyl-CoA/acetoacetyl-CoA, what can ketogenic amino acids be converted to
ketone bodies
fatty acids
name of amino acids which can degrade to pyruvate/TCA cycle intermediates, or can be converted into glucose
glucogenic amino acids
alcaptonuria occurs if degradation of what two things is blocked
phenylalanine
tyrosine
degradation of valine,, isoleucine and leucine causes maple syrup disese. what does this cause, what ca prevent development
urine = maple syrup
mental and physical retardation
prevented via appropriate diet
phenylketonuria occurs when
phenylalanine accumulates in body fluids
low phenylalanine diet prevents severe mental retardation
what occurs if there is a defect in urea cycle enzyme
accumulation of intermediates, leads to elevated levels of ammonia
