Protein

Question 1

During the post absorptive state what is the b to s ratio

Answer 1

breakdown is generally 30% greater

Question 2

what will a protein rich meal due to synthesis

Answer 2

increase synthesis and decrease breakdown

Question 3

what occurs to b and s during prolonged exercise

Answer 3

increase in protein breakdown and decrease in synthesis

also small increase in oxidation

Question 4

Essential AA =

Answer 4

cannot be produced by the body

Question 5

non-essential AA

Answer 5

can be produced by the body

Question 6

branched chain AA

Answer 6

leucine, isoleucine, valine (only AA oxidized by muscle)

Question 7

what is the importance of leucine

Answer 7

potent stimulator of protein synthesis (pathway that stimulates and regulates protein synthesis)

Question 8

fate of AA during exercise
Glucogeneic AA

Answer 8

readily converted to pyruvate, or TCA intermediates; many aa are gluconeogenic

Question 9

Fate of ketogenic AA

Answer 9

AAs readily converted to acetyl-CoA or acetoacetate; leucine, alanine and a few others

Question 10

All oxidized AA will lead to

Answer 10

Urea production

Question 11

when does urea increase

Answer 11

Urea is excreted, increased with exercise, especially carbohydrate-depleted situations

Question 12

RE and protein turnover

Answer 12

increase in turnover for 24-48h post-exercise

Question 13

what happens if nothing is eaten durin RE

Answer 13

Breakdown (MPB) > synthesis (MPS) if nothing is eaten!

Question 14

what is the net balance during RE

Answer 14

still negative regardless of time however after exercise it is closer to neutral

Question 15

what type of protein balance do we need to build muscle

Answer 15

positive

Question 16

what does adding/supplementing AA do

Answer 16

increases MPS and decreases MPB = positive balance for muscle gain

Question 17

what does RE do to change protein balance

Answer 17

Resistance exercise synthesizes the muscle to hyperaminoacidemia (without RE = the effect of AA on protein balance is much smaller)

Question 18

high protein intake may protect against

Answer 18

loss of lean mass during caloric restriction in athletes

Question 19

when do we see a plateau for protein consumption

Answer 19

We see a plateau over 20g after exercise as once past 30g it is very difficult to argue from a scientific standpoint

Question 20

how is fractional synthesis rate measured

Answer 20

by incorporation of 13C-leucine into the total protein poll

Question 21

fate of excess AA

Answer 21

MPS is saturable
We have a threshold for protein synthesis if we go beyond, will go elsewhere such as oxidation
And increases plasma urea

Question 22

_______ requirement for protein in strength-trained athletes might arise due to the extra protein required to support muscle protein accretion through elevated protein synthesis and increased breakdown during exercise

Answer 22

increase

Question 23

Strength training consistent with the anabolic stimulus for protein synthesis therefore it provides

Answer 23

increases the efficiency of use of protein, which reduces dietary protein requirements

Question 24

what is the best protein source and why

Answer 24

whey = fast digestion (rapid increase in plasma amino acids)
Whey causes greatest FSR at rest and after RE
This may be due to increase in leucine, which stimulates protein synthesis

Question 25

does whey or soy cause greater increases in insulin

Answer 25

whey

Question 26

what is the optimal leucine amount to maximize protein synthesis

Answer 26

5g (2g is threshold for eliciting a response)

Question 27

leucine and insulin can stimulate

Answer 27

AMPK and inhibit MTOR

Question 28

when exercise stops AMPK _____

Answer 28

decreases and inhibition stops which ensures that protein synthesis occurs after contraction

Question 29

CHO-induced spike in insulin will

Answer 29

increase net protein synthesis

Question 30

leucine stimulates protein synthesis via

Answer 30

mTOR pathway

Question 31

how does leucine stimulate protein synthesis

Answer 31

leucine and in theory insulin can stimulate AMPK which inhibits mTOR

Question 32

when exercise stops, AMPKK

Answer 32

decreases and inhibition stops (why we don't get a net positive during exercise)

Question 33

Addiding CHO had _____ effect on MPS

Answer 33

no significant

Question 34

as long as adequate ______ are consumed ( g)

Answer 34

EAAs (~6g)

Question 35

despite the large insulin spike...

Answer 35

MPS is not further increased by CHO and MPB is not decreased

Question 36

sufficient protein already maximally stimulates ____

Answer 36

MPS

Question 37

when is insulin most likely a facotr in MPS

Answer 37

only at rest not following RE

Question 38

is timing of CHO ingestion important (prior)

Answer 38

Protein prior - increased amount of AA taken up in the muscle - when protein stops protein synthesis goes up - higher protein synthesis before so already present for protein synthesis after exercise (gives a head start)

Question 39

is timing of CHO ingestion important (post)

Answer 39

- lower Phe before exercise - see an increase in synthesis but not as much as taking it prior

Question 40

in a repeated study in 2007 what were the findings

Answer 40

there was no benefit/ conclusive findings on timing effect of protein intake all it said is maybe taking it earlier is better

Question 41

what led to the greatest insulin spike and hyperaminoacidemia

Answer 41

Bolus timing and distribution of protein ingestion during recovery from RE - not suprising as there was greater food intake

Question 42

what was the bolus pattern

Answer 42

20g of whey protein every 3hrs

Question 43

t or f trained indivduals dont need as much protein

Answer 43

there is less breakdown/ doesnt change (go up) during RE in trained as turnover is not as great in trained

Question 44

do older adults need more protein

Answer 44

older adults are anabolic resistant and thus need more protein to get the same stimulation - thresholds for maximizing protein synthesis are higher in older indivduals

Question 45

anabolic response to an exercise stimulus is ____ in older adults

Answer 45

reduced

Question 46

Does BCAA supplements stimulate MPS

Answer 46

not alone

Question 47

increased arterial BCAA levels saw

Answer 47

no increase in muscle protein synthesis

Question 48

why is phenylalanine uptake a better index of protein syntehsis than leucine

Answer 48

leucine does not stay in the protein pool as it is a branched aa where phenylalanine will be consumed and stay in the protein pool

Question 49

why doesn't BCAA work

Answer 49

you now have a messed up balance of AA so it breaksdown its own pool of protein to establish balance - can't stockpile BCAA, we need all ECAA