The last of the macro’s
Macronutrients are an important source of energy for the body and in this chapter we’ll look at what roles they play to better understand each Macronutrient individually.
Macronutrients are made up of Fat, Protein and Carbohydrates and affect many processes such as:
Our metabolic function Our hormone production Our body composition Our ability to absorb nutrients and digest food Our immune system health and many more!
We took a look at Carbohydrates and Fats in earlier chapters so lets look at Protein for now.
Proteins are made up of both carbon and hydrogen molecules but unlike carbohydrates and fats, they also contain nitrogen as part of their amino groups.
The smallest unit of Protein is the Amino Acid (many of you would’ve heard of these) and these are similar to the monosaccharide or fatty acid that we’ve spoken about previously. When amino acids are joined together they form a Peptide chain which go on to make the primary protein structure.
Most proteins however aren’t just long chains of amino acids. These chains form secondary, tertiary and quaternary structures.
When we consume food, most proteins are found in complex secondary, tertiary and quaternary forms but once digested, are broken down into amino acids and small peptides. We hope this makes sense as it can be a little tricky to get your head around.
Digesting complex proteins into small peptide chains and amino acids all begin within the stomach. Gastric Hydrochloric Acid breaks the secondary, tertiary and quaternary structures of the ingested proteins apart and an enzyme (pepsin) starts to break down the eosin bonds.
Next stop of course is the Small Intestine where proenzymes enter the scene. These proenzymes are usually inactive so activation by other enzymes and chemicals that are released into the small intestine are required to carry out further digestion of the peptide chain.
Different amino acids and peptide chains are absorbed differently through the cells of the intestinal brush border. Now if you remember from earlier chapters you may recall ATP? These cells are where the vast majority of your energy comes from and all peptides rely on ATP to carry them through the blood stream.
Di and Tripeptides use different carriers to amino acids and therefor take longer to enter the bloodstream due to the traffic jam/ not enough transportation.
Quick Note: Large dietary intakes of free form amino acids are found usually in supplement form and therefor help create the traffic jam we talked about just above.
There are several ways for these amino acids and peptides to be distributed:
Can be used for energy.
Can be used to create no proteins such as hormones and new digestive enzymes.
Still with us?
For every 100g of amino acids consumed:
Roughly 20g will be used for protein creation in the liver Roughly 60g will say goodbye in the liver and Roughly 20g will go into systemic circulation
Out of the 20g of protein creation in the liver:
Roughly 14g will remain and 6g will be exported to the plasma in the form of Plasma Proteins.
Protein is an extremely important part of our nutrition as our bodies can’t store it the same way as Carbohydrates and Fats, we constantly lose amino acids and if the body doesn’t have them readily available, they’ll go searching for valuable sources to break down (like muscle) in order to create the fuel required.
We hope this made sense, as you can imagine there’s far more to learn about protein however we’ve tried to make it easier to understand and keep the information to the important facts. You should now be able to use this information alongside the other chapters to have a better understanding of Macro Nutrients.
Justin Beard Pn1