Protein Metabolism + Nutrition in Endurance Performance Flashcards Preview

Sports Nutrition and Metabolism Yr 2 > Protein Metabolism + Nutrition in Endurance Performance > Flashcards

Flashcards in Protein Metabolism + Nutrition in Endurance Performance Deck (49)
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1

Define protein

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

2

What are the 3 processes of protein production

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

3

Give 3 functions of proteins

- Provide structure
- Hormones
- Antibodies
- Transporters
- Enzymes
- Movement

4

Define Muscle) protein synthesis

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

5

Define Muscle) protein breakdown

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

6

Define (Muscle) protein balance

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

7

Define Amino acid oxidation

o The breakdown of intracellular amino acids for energy production.

8

Define Amino acid uptake

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

9

Define Amino acid utilization

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.

10

What are the 3 possible classes of proteins

Essential
Non-essential
Conditionally essential

11

Define primary structure of protein

Sequence of amino acids

12

Define secondary structure of protein

Local folding of polypeptide chain

13

Define tertiary structure of protein

three dimensional folding pattern of a protein- side chain interactions

14

Define quaternary protein structure

protein consisting of more than one amino acid chain

15

What is deamination

removal of amine group (NH3) in liver

16

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

350g/day

17

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

1-2% a day

18

What is a stable isotope

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

19

give 3 factors affecting protein turnover

- Habitual diet
- Protein intake
- Energy intake
- Hormones
o Insulin
o Steroids e.g. testosterone
- Exercise

20

Give 3 potential roles of dietary protein in sport and exercise

 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

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

1 hour post-exercise

22

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

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

23

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

positive net balance

24

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

A) increased myofibrillar

25

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.

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

26

What is central fatigue theory

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

27

What is the serotonin central fatigue theory

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

28

Describe the central fatigue theory mechanism

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

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

• some evidence of improved mental performance
• slower runners (3.05 - 3.30 h) improved performance

30

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

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