Protein Flashcards
How is protein metabolised?
Protein can form acetyl Co-A which can then be broken down in the Krebs cycle to make energy.
What are free amino acids?
Protein gets broken down into free amino acids, these get used to form new protein. Not all AAs survive he protein breakdown so that’s why we need to continue to ingest more.
What is nitrogen balance?
when we are weight stable we are in nitrogen balance.
When we gain weight we are in positive nitrogen balance. When we lose weight we are in negative nitrogen balance.
We hope to be in positive nitrogen balance for strength training.
What can amino acids be broken down into?
Either urea or oxidised to form alpha-keto acid
What is positive nitrogen balance?
If we are gaining weight. The subject has retained nitrogen
What is negative nitrogen balance?
If we are losing weight. The subject is losing net nitrogen
What is methyhistidine excretion
When contractile proteins are degraded 3-Methyhistidine cannot be recycled within the muscle and is excreted in the urine. This is a method of measuring protein turnover
What a tracer techniques?
Methods of measuring protein turnover. Using radioactive proteins to measure how many of those labelled AAs end up in the protein that we’re interested in.
How is positive protein balance achieved?
increased muscle synthesis
Decreased protein breakdown
How does feeding after exercise effect adaptation?
After exercise protein synthesis will only occur if feeding occurs. No feeding = no adaptation
Hpw much % does AA contribute to energy at rest?
5-15%
This decreases during exercise
What is the recommended protein intake for the sedentary population?
0.8g/kg
What is the recommended protein intake for endurance athletes?
1.2-1.7g/kg
What is the recommended protein intake for strength athletes?
1.6-1.8g/kg
