Nutrition - Proteins

Ok, so now for the really in depth stuff...

What are proteins made from? The answer is amino acids! There are 20 in total. 9 of these are essential whilst 11 are non-essential.

When animal and plant cells join together amino acids, it forms something called a peptide. These peptides have different names depending on how many amino acids there are. The end of the process results in something being formed called proteins! There have to be 100 or more amino acids until these proteins are formed, unless 2 or more polypeptide chains come together and fold repeatedly to form 3 dimensional shapes. These shapes/structures help to show its function in the body.

So... 2 amino acids are called "Dipeptide"
3 amino acids are called "Tripeptide"
4-9 amino acids are called "Oligopeptide"
10 or more amino acids are called "Polypeptide"

So, I mentioned before that there are 9 essential amino acids, these are:

Phenylalanine, methionine, tryptophan, threonine, lysine, isoleucine, leucine, valine, and histidine! (Told you its complicated!)

Now I'll name the 11 non-essential amino acids, these are non-essential as they aren't always required to be a part of a daily diet.

Glycine, alanine, tyrosine, serine, cysteine, proline, glutamic acid, glutamine, aspartic acid, asparagine, arginine!

Complete proteins contain all 9 of the essential amino acids, whilst the liver will synthesise the non-essential amino acids. Complete proteins come mainly from animal sources, these are meat, eggs, dairy, fish and poultry. However, there are some complete proteins that don't come from animal sources, these are soy foods, quinoa and buckwheat.

Plants also contain proteins but they are of a lower value biologically compared to complete proteins. These are called incomplete proteins. These include cereals and grains, cereal products, pulses, vegetables and nuts.

For vegetarians, good combinations of foods are vital considering there are no meats. These include pulses and grains, rice and pulses, nuts and vegetables and seeds and vegetables.

What does protein do? Keratin in the skin, muscle tissue, collagen in bone and connective tissue are all components of the body in which protein helps to form the key framework.

Various processes are regulated such as insulin controlling the blood sugar, enzymes speeding up reactions and white blood cells fighting infection.

During fasting or endurance events like long runs, protein is useable source of energy although it isn't the main source. ATP can also be produced through glucose, fatty acids and ketones, all things that protein can be converted into.

Catabolism relates to breaking down larger structures into smaller ones whilst anabolism relates to the building up process that happens in the body. Anabolism occurs during rest whilst catabolism occurs during intensive exercise.

Lastly, the following figures relate to the daily protein requirements for each type of person. The figures relate to the grams of protein per kilogram of body mass:

A sedentary adult - 0.8
A recreational adult exerciser - 0.8-1.5
An adult endurance athlete - 1.2-1.6
A growing teenage athlete - 1.5-2.0
An adult that's building muscle mass - 1.5-1.7
And lastly for the estimated upper limit for adults - 2.0

My next post will be focusing on Carbohydrates...