Protein Synthesis and Protein and Protein Bioavailability
Let’s define protein in simple terms. Protein is an amino acid. Let’s define amino acid in simple terms. Amino acids are molecules that combine to form protein. On a side note amino acids and proteins are the building blocks of life.
What are the differences between protein and amino acids? Amino acids in scientific terms can be defined as organic compounds containing a basic amino acid (-NH2 and carboxyl group - COOH) side chain (R group)that varies depending on the amino acid.
It is important to note once again that NH2group and carboxyl group - COOH are amino acids and to re- emphasize - amino acids are smaller molecules that make up protein. Researchers have identified some 500 natural occurring amino acids and 20 can be found in our genetic code.
In the form of proteins amino acids form the second largest component of human muscles and other tissues and first being water. Once again amino acids are the building blocks of protein.
We in the fitness world sometimes only think of amino acids in a monolithic manner of building muscle, however amino acids play a crucial role in many other vital aspects of the human condition. For instance, amino acids play an intricate role in protein synthesis. This is where it gets complicated, so I’ll break it down. Protein synthesis refers to a biological process whereby amino acids are assembled (Protein assembly is the process of using messenger RNA (mRNA) to create proteins at ribosomes). What is RNA? - (A molecule present in all living cells - Ribonucleicacid).
What is the function of RNA - Ribonucleicacid? RNA carries genetic information and directs the production of proteins).
What are ribosomes? Ribosomes translate information encoded in messenger (mRNA)
What is translation? Translation is the process by which a protein is synthesized from the information contained in a molecule of messenger RNA - mRNA).
What is the difference between RNA and mRNA ? (RNA is involved in building proteins and mRNA acts as the messenger. mRNA has the recipe for protein).
It’s important to understand that in protein synthesis mRNA has the recipe, ribosomes organize the ingredients then translates the organized ingredients from mRNA to the RNA where the RNA takes the organized ingredients and turns them into protein amino acids. This is called translation. mRNA does not translate to DNA as it does not enter the nucleus of the cell. The nucleus of the cell is where your DNA is. Amino acids and gene expression: Gene expression is the ability of amino acids to modulate the initiation phase of mRNA translation. eIF2 plays a central role in gene expression by what is considered a rate limiting step. (A rate limiting step is the slowest out of all the steps that occur for a given chemical reaction).
eIF2B protein helps regulate protein production - (synthesis) - in the cell by interacting with eIF2 protein. The eIF2 protein is involved in initiating protein synthesis.
Amino acids glutamate and GABA - (gamma - Aminobutyric acid) are neurotransmitters.
So now we understand protein synthesis, we understand our body makes amino acids and these amino acids make protein. There are nine however amino acids our body doesn’t make and these nine along with the other amino acids makes up the twenty amino acids. These twenty amino acids make what is called “essential amino acids”.
So we have now the understanding that amino acids are molecules that make protein through a process called protein synthesis by which mRNA has the recipe and the recipe is transcribed by the ribosomes and the RNA synthesis’s the information and makes protein.
What is Protein Bioavailability? Protein Bioavailability is the percentage of amino acids in a protein source that the body can absorb and use. Protein with high bioavailability are easily absorbed after digestion allowing the body to use a higher percentage of the amino acids.
What foods are highest in bioavailability? Animal based proteins are more bioavailable than plant based proteins because they are a complete protein meaning they contain all of the essential amino acids. Whey protein is the most bioavailable. Absorption rate of animal protein is ninety to ninety five percent and plant based protein is around eighty percent.
It’s considered that the body can absorb about twenty to twenty five grams of protein at one time and more than thirty five grams of protein at one time provides to many building materials for muscle. With more research however there have been studies showing that in muscle analysis four hours after consuming twenty grams of whey the same amount of protein absorption in the muscle cells is the same as if one consumed say forty grams of whey protein. This study indicates that protein absorption is around four hours and protein through out the day is the best way to maintain protein in the cells of muscle and twenty grams at a time is sufficient.
The same research scientist in muscle analysis showed that one hundred grams of protein at one time stayed in the cells of the muscle for twelve hours. In other words more protein doesn’t mean more protein absorption in the cells of the muscle but does mean at a hundred grams of protein, protein is still in the cells of muscle twelve hours later.
What is the right amount of protein in one day? I want to preface this by saying that the amount of grams consumed in one day can vary because of ones needs. For instance a body builder with the sole purpose of building muscle would need a greater amount of protein than say a long distance runner. Studies show about 0.8 grams per kilogram of body weight for an average sedentary adult. An example would be a one hundred and fifty pound male would take in about fifty four grams of protein. A sedentary woman would take in forty six grams per day. For an active person around one hundred grams per day and for those who train and are every day exercisers a good estimate is one gram per body weight which would be for a male weighing one hundred eighty pounds, around one hundred eighty grams of protein and the same for a women, maybe a little less. Unless you have something like kidney disease it’s almost impossible to take in too much protein as the body will discard the excess protein through urination.
The mechanism for protein absorption is tripeptides - three amino acids and dipeptides - a compound of two amino acids. These amino acids are absorbed in the duodenum and the jejunum of the small intestine. The amino acids pass through the interstitial brush border - a chemical barrier through which food must pass and be absorbed.
On a side note the interstitial is the fluid membranes of fascial tissue. Once absorbed these amino acids inter the blood stream into to the cells of every organ in your body. We have three macro nutrients. Fat, sugar and protein and protein is by far the most important. Protein is the building blocks of life and act to repair and maintain cellular continuity.
Stay tuned for my next blog.