Flashcards in REVISION GUIDE LIVER: NITROGEN Deck (73)
what is the role of amino acids?
they are the building blocks of proteins/peptides
what is the structure of amino acids?
have an amino group, a carboxyl group, R-side chain and a carbon backbone
what is the role of the R group of amino acids?
they change the amino acid
what is the function of amino acid heterogeneity?
it allows proteins to fulfil many different functions
what are essential amino acids?
they are amino acids that cannot be produced
they are needed in diet
what are non-essential amino acids?
they are simpler amino acids
they body is able to produce them de novo
what are conditionally essential amino acids?
under certain circumstances they may need to be consumed in the diet
they may be dependent on the consumption of other amino acids
what are the 2 types of amino acids?
what are glucogenic amino acids?
the carbon backbone is used in gluconeogenesis or TCA cycle intermediates
what are ketogenic amino acids?
the carbon backbone produces acetyl CoA or acetoacetyl CoA
which amino acids are solely ketogenic?
what are amino acids used for?
production of non-protein molecules
which amino acids are essential?
which amino acids are conditionally essential?
which amino acids are non-essential?
what type of bonds join together amino acids?
how many amino acids are found in dipeptides?
how many amino acids are found in polypeptides?
how many amino acids are found in proteins?
what are the sources of nitrogen?
diet - amino acids from proteins
how is nitrogen lost?
via the gut and kidneys (urea)
renal excretion = 70g/day
faecal loss = 10g/day
when is nitrogen balance in equilibrium?
when intake/output are equal
where does the body maintain a free pool of amino acids?
in the blood
what happens to nitrogen during the fasting state?
body protein is used (free or skeletal muscle (80%))
what happens to nitrogen during the fed state?
the net contributor is diet
what are the different pathways for protein degradation?
lysosomal and ubiquitin-dependent pathways
what should nitrogen intake be per day?
what are free amino acids split between in the body?
- free pool in blood
- proteins in the body (~10kg)
- metabolic precursors - loss of amino group and carbon backbone is used in glycolysis and TCA cycle
where are amino acids stored?
they are not stored
they always have a function