Biochemistry-Creatine and Protein Supplements Flashcards
What is the protein RDA for men and women?
.8g/kg
What is the most protein someone’s body can actually utilize after a meal?
.25g/kg or about 15-25g per serving
What happens to excess protein in the diet?
It is oxidized for energy. This is why it is good to stay within 15-25g per serving
What problems can result from high protein diets?
Excess net acid load, increased loss of calcium due to net acid load, increased fluid requirements and insufficient carb intake.
How can you assess the protein status of an individual?
Anthropometric assessment (BMI and arm circumference) and labs (serum albumin, urinary creatine excretion)
What serum markers are used to assess protein status? What are the pros/cons of each marker?
Albumin (long half life so it’s not sensitive to early detection), Transferrin (shorter half life, but can be misleading because it’s an acute phase reactant) and Transthyretin/Prealbumin (shortest half life of 2 days)
What are particularly strong signals for protein synthesis?
Muscle contraction, leucine and insulin
How would resistance exercise change protein metabolism?
Muscle contraction is a strong signal for protein synthesis and it will decrease protein breakdown between meals.
Where do casein and whey proteins come from?
Milk
How does protein ingestion affect protein metabolism?
Whey and soy actually increase insulin levels. Insulin decreases protein breakdown in muscle.
What is the difference between fast and slow proteins?
Fast = rapid spike/peak in AA acid level (whey). Slow = smaller increase in AA that is maintained over time (casein).
Why do some people eat cottage cheese before working out?
It is casein protein and increases AA acid levels in your blood that are available for protein synthesis
What are the essential amino acids?
Amino acids that cannot be synthesized by our bodies: His, Iso, Leu, Lys, Met, Phe, Thr, Trp, Val.
What are the conditionally essential amino acids?
Amino acids that can be synthesized by our bodies, but may need supplementation due to rapid use: Cys, Gly, Pro, Tyr, Arg, Gln, Selenocystenine and Taurine.
How is leucine metabolized during protein synthesis?
Leucine->alpha-keto-isocaproic acid (KIC)->beta-hydroxy-beta-methylbutyrate (HMB)
How is arginine metabolized?
Agmatine, Creatine, Citrulline or Ornithine.
Where does creatine come from?
S-adenosyl methionine, glycine and arginine.
Why do people use creatine?
Creatine synthesis is a huge burden on the body’s amino acids. It is used in creatine phosphate as a reservoir for quick energy stores during exercise.
