wk7 Flashcards
what are the roles of amino acids
*central roles in the metabolism of many organs and tissues
* precursors of protein synthesis
* precursors for the synthesis of neurotransmitters, hormones, DNA and RNA
what is an important function of the liver
converts ammonia to urea, is excreted in urine
what is the structure of an amino acid
amino group, carboxyl group and r group and H
how many grams of protein in nitrogen
6.25g of nitrogen = 1g of protein
how to calculate nitrogen balance
- Determine nitrogen excretion – urine, faeces in 24hr period
- Determine nitrogen intake – measure protein intake, grams per day times by 6.25
- N balance = 2 minus 1
what is the recommended amount of protein
0.8g of protein/kg bw/day
what are the limitations of nitrogen balance
- No information of tissues
- Lack of sensitivity, only gross measure of intake and excretion
- Zero balance on low intake may reflect accommodation (similar to low EA concept)
- Positive balance may not relate to lean body mass
what is the intracellular amino acid pool
acts as a storage for products of protein synthesis and breakdown
this is in the blood
when are we able to take on the most protein
straight after exercise, they’re more sensitive to metabolism work
what is different about mps and mbs within athletes compared to normalm
the synthesis stage is lengthened and breakdown is shortened, allowing them to gain more muscle mass
why does MBS raise during sleep
because we’re in a ‘fasting’ state
when do we gain the most muscle mass
when resistance training is linked with amino acid intake
what is the muscle protein turnover per day
1-2% around 300-600g of protein
complete renewal takes over 3-4 months
what is different in training responses between resistance and endurance
Resistance exercise – increases the synthesis of force producing proteins
Endurance exercise – increases the synthesis of energy producing proteins
recommended amount of protein intake
If you ingest 0.8g protein/kg/day there is a minimal risk of protein deficiency
why is over 0.8g/kg bw beneficial for athletes
- Repair, replace and remodel damaged proteins
- Optimal function of metabolic pathways using amino acids
- Support lean tissue maintenance
- Support optimal function of the immune system
how long does the augmented mps stage last for
1-2 days max, then back to normal uptake levels
what is the max amount of protein we can ingest
Maximal protein intake is capped at 2g/kg/day, after around 1.6 there is a plateau that beings to form
what are the estimated average requirements (EAR) of protein intake
2.1g/kg/d
what are the recommended dietary allowance(RDA) for protein
2.6g/kg/d
optimal dose for younger healthy athletes
0.24g/kg/d
optimal protein dose for endurance athletes
20-30g protein is sufficient
post exercise recovery requirement of protein
2g/kg/d
why is whey good
fast acting
short-simple peptide chains
chronic adaptions to training (change in protiens)
more myofibrillar proteins = muscle mass
more mitochondrial proteins = aerobic capacity
more sarcoplasmic proteins = responds to nutrition
why is it optimal for athletes to take protein
replace repair and remodel
optimal function for metabolic pathway
support lean tissue mainteneance
support function of immune system
why is exercise plus protein so beneficial
exercise stimulates elevation of MPS
the augmented fed state of MPS is elevated after exercise for 2 days
