Amino Acid Metabolism Flashcards
what do we need to do before we metabolise AA
remove the amino group via transamination and deamination
tran
transfer amine group from the amine group of aa and swap with the =O of ketoacid
how is tran helpful?
mostly converted to glutamate / aspartame
and they can easily be inserted into the urea group which allows for them to bereaved more safely
formula and enzymes for the 2 types of the transamination reactions
- ALT ; Alanine + a-ketoacid = a-ketoacid + glutamate
- AST ; glutamate + oxaloacetate = a-ketoacid + aspartate
- enzymes = AST / ALT
- cofactor = pyridoxal phosphate a vitamin B derivative
clinical releveance
and example
blood test look for AST ALT for liver functioning ^ in liver damage/ toxicity/ autoimmune liver disease / amanita phalloides mushrooms is toxic to liver so ^AST/ALT observed
deamination
remove amine group as free ammonia (NH3)
occurs in liver and kidney (urea cycle in the liver)
importance of deamination
for metabolism is dietary D-amino acids into L amino acids so in can be used by the body (found in plants and microorganisms)
- ammonia must be removed by the body since its very toxic, so it is ultimately converted into urea and removed in the urine
enzymes
aa oxidase
glutamate dehydrogenase
glutaminase
urea
high nitrogen content 2 amine groups
innert in humans but bacteria can convert it to ammonia
important in removal of nitrogen + osmotic role in kidney tubules
urea cycle enzymes and their control pattern
5 enzymes
down regulated with low N (protein) , unregulated with ^ N (protein)
high protein diet/ low
clinical condition
up regulated
down regulated
referring syndrome; td to low protein diet their urea enzymes were down regulated and therefore eating a rich protein diet rapidly there wasn’t sufficient capacity in the urea cycle to deal with the ammonia levels
risk factors of referring syndrome
treatment
- physiological issues i.e wasn’t eating
- malnourished
- marasmums
- BMI <16
- 5 to 10kcal/kg/day increase gradually through the week
N metabolism involved
N balance and Protein turnover
major N containing compaoitn
CK PURINE AND PYRIMINDE NT (dopamine) Proteins hormones (adrenaline)
CK
immediate source of ATP
CK => creatinine and
found heavily in skeletal muscle and heart
Creatinine is the clinical marker
rate produced is proportional to the mass men (14-26
W 1-20mg/kg b males have more muscles than men
other reasons why CK used as marker
- measure heart damage post MI (b not often instead troponin is used b CK nonexclusive to the heart)
- kidney damage ( b urine removes it, ^ CK suggest kidney failure of sorts)
N
2kg
free state (not in aa)
input 16g N from diet
output 2g nails, hair / 14g faces and urine
what is nitrogen balance
the balance between N in and out the body
N+ = more in than out , normal d muscle builder or pregnant or adult recovering from malnourishment
N- = less intake than outtake , not normal causes malnourishment, trauma, infection
P turnover
free amino acid pool (added from thebe diet/ de novo (make it yourself) )
this free AAused to synthesis P which then are broken down via proteolysis
these AA are a source of carbon dn therefore can used to generate energy like FA can but you must remove amine group tho first to stop amine formation, this is done in the liver and the amine group can be converted into urea and removed in urine , but the C skeleton can be used depending on whether its a ketogenic or glutogenic AA can be used to either from ketone bodies (ketogenic AA) or gluconeogenesis (glycogenic AA) ,these from energy
ketogenic and glycogenic AA
K = lysine and lueocine G = Alanine, cysteine
when and how do we mobilise these P reserves
- in extreme starvation
- controlled by hormones ;
- Insulin and growth hormone ^ P synthesis ^ P degradation
- Glucocorticoids e.g cortisol v P synthesis ^ P degradation
clinical conditon associated with control over mobilising P
Cushing’s syndrome = excess cortisol therefore ^ firstly overweight due t ^ cortisol and so their skin stretches but due to ^ P degradation p has STRIAE as structure of the skin is weakened
Who needs specific aa and what is it called?
pregnant androids need arginine, tyrosine, cysteine d ^ rate of P synthesis
known as conditionaly essential
Who needs specific aa and what is it called?
pregnant androids need arginine, tyrosine, cysteine d ^ rate of P synthesis
known as conditionally essential
