Proteins And Amino Acids - Building Blocks Of The Body
Every day, we take in proteins from the nutrition. The word protein is derived from the Greek word proteins and means primary. As well as carbohydrates and fats they belong to the group of macronutrients. In the digestive tract, they are splitted into amino acids, which are composed to endogenous proteins. Human cells like brain and muscle cells contain a very high percentage of amino acids.
Seeing it simplified, amino acids the building blocks of the body cells. It is not possible to build or repair cells without them, for instance if there are small ruptures in the muscle tissue after an intensive workout 1.
Meanwhile 22 proteinogenic (protein building) amino acids of the human body are known. They are needed for the development of peptides and proteins. At adult age, the organism is able to produce 13 amino acids itself. Nine more have to be taken in with the nutrition, because the body cannot synthesize them. They are called essential amino acids.
- histidine (foods with histidine)
- isoleucine (foods with isoleucine)
- leucine (foods with leucine)
- lysine (foods with lysine)
- methionine (foods with methionine)
- phenylalanine (foods with phenylalanine)
- threonine (foods with threonine)
- tryptophan (foods with tryptophan)
- valine (foods with valine)
The certain order respectively chain of amino acids is called amino acid sequence. If there are more than 100 amino acids in the sequence, it is called protein. If the chain has less than 100 amino acids, it is a peptide. The proteins from the nutrition are disassembled into the amino acids, which the body composes to amino acid sequences.
Effects Of Amino Acids And Proteins
Amino acids, peptides and proteins play a major role for many different bodily functions. Mainly, they are needed for the cell and tissue buildup. The connective tissue for instance is also built with the help of the structural proteins collagen and elastin. Proteins are also very important for growth and development of children (while pregnancy as well) and adolescents 2.
Amino acids are parts of hormones and enzymes, which are part of the regulation of metabolic processes. Important to name is the hormone insulin, which controls the blood sugar level. The proteins also have influence on the acid-base balance and the fluid balance (e.g. aquaporins).
The amino acids are also composed to so-called motor respectively muscle proteins myosin and actin 3. They play a very important role concerning muscle contractions and movements. With the help of the muscle proteins, the muscle can convert the chemical energy to kinetic energy. As is known proteins belong to the most important nutrients when it's about building up muscles. The muscle fibers for instance consist of 20% proteins. Creatine, which is made of the amino acids methionine, arginine and glycine, is also involved in the energy supply of the muscles.
Antibodies (immunglobulins) are also made of amino acids. So, proteins support the immune system. Additionally, amongst other things, oxygen and micronutrients are transported to their target regions in the organism with the help of plasma and transport proteins (like hemoglobin, myoglobin and albumin). In this connection, proteins are involved in the storage of iron in the liver, which in form of ferritin is necessary to transport oxygen from the lung.
But also in the formation of neurotransmitters, the amino acids are needed. Neurotransmitters are needed for the transmission of impulses from nerve cell to nerve cell. Proteins are also part of the retina. Rhodopsin is such a protein that participates in the retina as a visual pigment in the visual abilities. Amino acids which are composed to keratin (protein fiber) are also the main components of hair and fingernails.
Like the other two macronutrients fat and carbohydrates, proteins can also be used for the energy supply of the body. The calorific value per gram of protein is 4.1 kcal 4. Nevertheless proteins are not the preferred source of energy. They are burned when fats and carbohydrates are used up.
For this purpose the body can detach proteins from the tissue (such as the muscles) or use proteins supplied by the nutrition to form glucose by gluconeogenesis. The result is muscle loss. Moreover, the superfluity of the amino acids that are absorbed during a excess of protein are converted into glucose and are used for energy production 5.
Storage And Absorption
Amino acids can only be stored for a short time in the so-called amino acid pool of the body. The muscle tissue is the largest storage of proteins and possibly should not be touched. Another reason why amino acids must be taken in daily. The absorption rate of the amino acids depends on the composition of the diet (e.g. protein quality and quantity of the amino acids), the individual genetic conditions but also on whether there is physical stress or not 6. For these reasons, the body absorbs proteins at different rates.
Proteins For Muscle Growth
Without an effective training of muscle gain will not succeed. The sporting activities must be consistent with the supply of all nutrients, wherein the amino acids respectively proteins naturally play a major role. Athletes have ultimately not only a higher power and protein requirement. Nutrition organizations recommend physically not active people to take in 0.8 g protein per kg body weight during the day 7. In contrast, 1.2 to 2 g per kg are recommended for athletes. According to scientific studies, athletes can also reach an optimal protein intake with a well-planned vegetarian (vegan) diet 8.
Vegetable Proteins Enhance Your Bone Density
It is supposed that excessive consumption of proteins from foods that have a high potential acid burden on the kidneys have a negative impact on the bone density (see lowering the risk of osteoporosis) 9. Studies from 2012 show that vegetable protein sources are healthy for the bones under certain conditions. The higher intake levels of vegetable protein are ideal for bone health and for protection against osteoporosis when an adequate calcium and vitamin D is supply is ensured 10.
Vegetable Protein Lowers Blood Pressure
According to scientists, there is a significant inverse relationship between the intake of vegetable protein sources and the blood pressure 11 12.
It was demonstrated that a vegetable protein intake may be associated with a lower systolic and diastolic blood pressure.
Other studies found that a partial replacement of carbohydrates by proteins can also lower blood pressure, improve lipid level values and the expected cardiovascular risk can be reduced 13.
Supplying The Body With Amino Acids
In order not to jeopardize the composition of peptides and proteins from amino acids and not to interfere with the body's functions, all nine essential amino acids must be taken in throughout the day.
Already missing only one essential amino acid can impair the function of all proteins. An amino acid deficiency (protein deficiency) negatively affects protein synthesis, which among others reduces the physical performance and affects the muscle building process. Food with protein can be found in the list view.
Proteins In The Vegan Diet
All essential amino acids are contained in plant foods. However, the units contained usually fluctuate greatly from food to food.
Therefore, especially with regard to the receipt of all body functions but also from a sporting perspective (muscle growth and maintenance), it is advantageous to deal with the natural occurrence of amino acids in plant foods and products.
Because with the proteins bound in plants an absolute equivalent nutrition can be reached as with proteins of animal origin. Combining proteins with selected foods to a specific amino acid profile is not necessary 14. Mostly, this arises naturally when the diet is varied. Make sure the vegan diet is varied and full-fledged, so that the need of protein respectively of amino acids can be covered without any dietary supplements.