Dietary Protein Flashcards
where is food broken down into amino acids
the stomach
- acidic stomach conditions begin to breakdown food by the work of pepsin (pH 2)
where are the amino acids needed for protein synthesis obtained
food protein
after the stomach, where does food continue to be broken down
small intestine
what is protein turnover
proteins are continually being broken down and replaced, amino acids are recycled, some are used for metabolism
describe the role of protein maintenance in adults
total body protein fluctuates over short periods- decreased whilst fasting, increases after feeding
not usually a change over long periods
describe the role of protein maintenance in children
total fluctuates in the short term and also increases over time due to growth
what is deamination
carbon skeleton of amino acids can be oxidised to generate energy
nitrogen is not used to generate energy
the amine group is separated from the alpha carbon
outline the process of metabolism of ammonium ions
amino acid catabolism to produce ammonium ions
ammonium is toxic, it is converted to urea in the liver
what is the urea cycle
takes place in the liver hepatocytes
costs 4 high energy phosphate bonds
ornithine acts as a carrier for urea
urea NH2 groups form NH4+ and aspartate
how is urea disposed
via the kidneys as urine
what is the main source of nitrogen
protein
how is the need for protein determined
through nitrogen balance studies
what is an example of someone who will have a negative nitrogen balance
output is larger than input
trauma patient
what is an example of someone who will have a positive nitrogen balance
input is larger than output
growing child
what is an example of someone who will have a neutral nitrogen balance
healthy adult
