Protein Metabolism + Nutrition in Endurance Performance Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

Define protein

A

chains of amino acids, arranged into primary, secondary and tertiary structures which contain nitrogen.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the 3 processes of protein production

A

transcription, translation (initiation, elongation and termination) and post-translation modification

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Give 3 functions of proteins

A
  • Provide structure
  • Hormones
  • Antibodies
  • Transporters
  • Enzymes
  • Movement
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Define Muscle) protein synthesis

A

o The creation of new proteins from amino acids (as a result of initial transcription of the DNA).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Define Muscle) protein breakdown

A

o The degradation of whole proteins back to constituent amino acids.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Define (Muscle) protein balance

A

o The net result of muscle protein synthesis and muscle protein breakdown (Synthesis-Breakdown).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Define Amino acid oxidation

A

o The breakdown of intracellular amino acids for energy production.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Define Amino acid uptake

A

o The rate of transport of amino acids from one pool (e.g. the plasma) to another (e.g. the muscle cell).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Define Amino acid utilization

A

o The amount of dietary amino acids (obtained from dietary protein) that is used by the tissue and organs of the body for the above processes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the 3 possible classes of proteins

A

Essential
Non-essential
Conditionally essential

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Define primary structure of protein

A

Sequence of amino acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Define secondary structure of protein

A

Local folding of polypeptide chain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Define tertiary structure of protein

A

three dimensional folding pattern of a protein- side chain interactions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Define quaternary protein structure

A

protein consisting of more than one amino acid chain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is deamination

A

removal of amine group (NH3) in liver

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

In the average person,how much protein is synthesised each day?

A

350g/day

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

In the average person, what is the protein synthesis rate?

A

1-2% a day

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is a stable isotope

A

Isotopes function identically, but can be marked, so act as a tracer to measure net nitrogen balance.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

give 3 factors affecting protein turnover

A
  • Habitual diet
  • Protein intake
  • Energy intake
  • Hormones
    o Insulin
    o Steroids e.g. testosterone
  • Exercise
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Give 3 potential roles of dietary protein in sport and exercise

A
	Muscle hypertrophy 
	Muscle strength 
	Immune function 
	Central fatigue
	Glycogen re-synthesis
	Additional energy during exercise 
	Specific function of individual amino acids 
	Effects on muscle damage
21
Q

Bowtell et al 1998 found that leucine oxidation increased most when after exercise

A

1 hour post-exercise

22
Q

Hulston et al 2011 found what sort of protein balance during exercise

A

negative net balance, but exercise increased both protein synthesis and breakdown

23
Q

Protein ingestion before, during or after exercise promotes what sort of balance

A

positive net balance

24
Q
Protein ingestion is associated with which synthesis rates?
A) increased myofibrillar
B) decreased myofibrillar
C) Increased mitochondrial
D) decreased mitochondrial
A

A) increased myofibrillar

25
Q

In the trans-alp challenge, which group improved their performance?
o 7.6% cho-e solution and cho bars (placebo)
o 7.2% cho-e, 1.8% wp solution and cho/protein bars.

A

o 7.2% cho-e, 1.8% wp solution and cho/protein bars.

26
Q

What is central fatigue theory

A

Fatigue may be associated with inadequate central nervous system “drive” to the working muscle e.g. by neurotransmitters

27
Q

What is the serotonin central fatigue theory

A

Increased brain 5-hydroxytryptamine (5-HT) (Serotonin) concentration causes a deterioration in performance

28
Q

Describe the central fatigue theory mechanism

A
the selective transporter poses competition with branched chain amino acids (increasing tryptophan and serotonin) so... 
•	reduced [BCAA] and increased [fTryp]
•	increased fTryp : BCAA
•	increased fTryp transport into brain
•	increased serotonin synthesis
•	impaired CNS function
29
Q

Did Blomstrand et al 1991 show BCAA supplementation to improve mental and physical performance

A
  • some evidence of improved mental performance

* slower runners (3.05 - 3.30 h) improved performance

30
Q

Did Van Hall et al 1995 show BCAA/tryptophan supplementation improved physical performance

A

• No difference in time to exhaustion despite increased fTryptophan:BCAA.

31
Q

True or false: A hypocaloric diet decreases body mass, lean body mass and fat mass

A

False, Lean body mass increased

32
Q

What is the recommended protein dose?

A

RDI = 1.2 – 2.0 g/kg

33
Q

What is the timing consideration for protein ingestion?

A

o Protein ingestion in close proximity to exercise may facilitate muscle reconditioning
o Protein feeding during exercise does not appear to enhance exercise performance assuming adequate CHO is consumed.

34
Q

True of False: Tarnopolsky et al 1992 suggested a RDA for sedentary subjects to be 0.89 g/kg/day and 1.76g/kg/day for strength trained subjects.

A

True

35
Q

What is the anabolic stimulus for muscle production in the diet?

A

Protein

36
Q

Why does exercise cause an immediate reduction in muscle protein synthesis?

A

the priority is ATP for muscular contraction at the time

37
Q

What is more important in Rex training: intensity or carrying it out to failure

A

carrying it out to failure

38
Q

What is more important in Rex training: eccentric or concentric exercise

A

eccentric

39
Q

Why do we see an increase in MPB following exercise

A

protein breakdown replaces protein fibres with stronger, faster fibres

40
Q

If protein turnover is around 300-600g per day.. what can this increase too post-exercise

A

around 600-900g per day

41
Q

True or false: there is a golden 30 mins post-exercise

A

False-
protein synthesis is increased for up to 2 hours post. Plus, the body is sensitive to protein for all meals within this 2 days

42
Q

What does net protein accretion result in

A

Hypertrophy

43
Q

When should whey protein be ingested

A

ingested and absorbed faster than casein- so post-exercise

44
Q

When should casein protein be ingested

A

pre-bed

45
Q

What is leucine better at than other amino acids?

A

Faster FSR

46
Q

True or false: CHO can improve MPS

A

There was an increase in MPB with CHO and exercise, but CHO reduced MPS with exercise

47
Q

What is the RDA for protein? Sedentary

A

0.89 g/kg/d

48
Q

What is the RDA for protein? ReX trained

A

1.76 g/kg/d

49
Q

How much protein post-exercise will induce an optimal anabolic response

A

20-30g