amino acids and proteins Flashcards
what are essential amino acids
amino acids supplied by food -> cannot be made in the body
aminoacidopathies
inherited enzyme defects that inhibit metabolism of certain amino acids for non essentail amino acids
- build up of toxic amino acids/byproducts
amino acid analysis
- drawn after 6-8 hr fast
- plasma removed from cells
what is differential solubility in regards to protein properties
when a positive charge is present, the protein dissolves easier
define isoelectric point
when amino acids have no net charge and depend on the pH of medium to dictate charge
define adsoption
ability to have water cling to the surface of the molecule -> albumin has this
globular proteins
symmetric
soluble in saline
fibrous proteins
asymmetric
water insoluble
protein functions
- energy produciton
- water dist (colloidal osmotic pressure maintenence)
- buffering
- molecule transport
- glycoprotein production/other productions
define conjugated proteins
proteins composed of more than 1 tertiary structure attached to a non protein prosthetic group
mucoproteins
> 40% of weight by carbohydrates
glycoproteins
10-40% of weigh tby carbohydrates
what are the plasma proteins
formed by albumin (54%) and globulins (46%)
- globulins = TP-albumin
factors affecting protein conc.
- nutrition
- physilogical changes (hyper/hypoproteinemia)
- synthesis rate
- extracellular production
pre-albumin
transport protein for thyroid hormones T3 and T4
- synthesized in liver and choroid plexus
albumin
- serves to maintain colloid osmotic pressure (oncotic pressure) by using adsoprtio properties of water
- mostly found in extravascular spaces (60%)
kwashiorkor
severe protein deficiency but normal calorie intake
- decreased serum albumin lvls
marasmus
deficiency of protein and overall calories
- normal serum albumin lvls
how is albumin measured
- colorimetrically (icterus, hemolysis and lipemia interferes)
- uses bromocresol green
alpha - 1 antitrypsin
- protects elastin in lungs by inhibiting neutrophil elastase in inflammatory response
- made in liver
- acute phase reactant
alpha - 2 macroglobulin
- acute phase reactant
- made in liver
- serine protease inhibitor
- measurment useful in renal disease and glom damage (big)
haptoglobin
- made in liver
- transport protein for free hemoglobin
- acute phase reactant
ceruloplasmin
- made in liver, also by macrophages and lymphs
- transport protein of copper
disease associated with ceruloplasmin
wilsons disease, decreases lvls
-> increase of free copper leading to deposition in brain and other areas
transferrin
- transports and stores iron
- NOT an acute phase reactant
fibrinogen
forms clots when activated by thrombin
CRP and HS-CRP
c- reactive protein and high sensitivity c reactive protein
- CRP increase lvls activates coag, compliment and LDL
- pos acute phase reactant
myoglobin
- stores intracellular oxygen
- when released due to extreme conditions can cause renal failure
- coordinates oxygenation of hgb by blocking other molecules
- increased in rhabdomyolysis
other proteins to know
- beta -2 microglobulin: surface of lymphs
- troponin: cardiac protein
- fetal fibronectin: amniotic sac lining
- CTX: bone turnover
protein level abnormalities
- hypoproteinemia: due to negative nitrogen balance
- hyperproteinemia: concentraion of proteins increases due to lower soln vol
