Proteins
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What are Proteins?
There are at least 10,000 different proteins throughout our body that make what you are and keep you that way. Proteins are the combination of hundreds and thousands of smaller units called Amino Acids, which are attached to one another in long chains. There are 20 types of amino acids, while 9 are the essential amino acids that we must obtain from our diets, and 11 non-essential amino acids which body can synthesis by itself when needed. The sequence of amino acids determine the structure and function of proteins.
Why Proteins are so important?
Proteins play an essential role in our body. They mostly working in the cell and perform various functions.
Growth and Maintenance
Our body requires protein for growth and maintenance of tissues. Generally, Same amount of proteins are broken down by the body and used to build and repair tissues, such as skin and muscles.
There are special situations that more proteins will be broken down by the body to meet its needs:
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Puberty period of development
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Illness or injury
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Pregnancy
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Breastfeeding
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Under physical pressures, such as fitness and power training
Enzymes
Enzymes are proteins that assisting thousands of biochemical reactions that take place within and outside of the cells. Enzymes combines other molecule in the cell that called substrates at key locations in their structure called active sites. This catalyzes reactions that are important to metabolism. Also, enzymes are highly specific and only bind corresponding substrates for corresponding reactions.
For example:
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Maltase that found in saliva, breaks the sugar maltose into glucose
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Trypsin that found in the small intestine, breaks proteins down into amino acids
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Lipases that found in the gut, help digest fats
Act as a Messenger
Some proteins act as a messenger, such as hormones. They are the chemical messengers that transmit signals between cells, tissues and organs to coordinate biological processes.
Most of the hormones are made by proteins and polypeptides, and transported to their target tissues or organs by the blood.
Some examples include:
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Insulin: Signals the uptakes of glucose or sugar into the cells, which regulates the blood glucose level
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Antidiuretic Hormone (ADH): Signals the kidneys to reabsorb water, which helps regulate the amount of water in the body.
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Melatonin: Signals the body to sleep or wake, which helps building sleep/wake cycles.
Formation of Antibodies
Proteins form antibodies to fight the infection.
Antibodies are in your blood. When the foreign invaders enter the cells, the body produces antibodies to bind to and inactivate foreign substances, like pathogens and toxins; or activate the complement system to destroy bacteria cells.
The most common antibody that present in the blood and tissue fluids is Immunoglobulins (IgG) which helps tackle the harmful invaders.
Transports Nutrients
Transport proteins bind and carry small molecules and substances, such as vitamins, minerals, glucose, cholesterol and oxygen, throughout the bloodstream, no matter into cells, out of cells or within cells.
Transport proteins are specific, and they are only binding to specific substances, for example:
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Hemoglobin: It carries oxygen from lunges to other body tissues, like brain, heart and muscles.
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Glucose Transporters (GLUT): It transports glucose to cells
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Lipoprotein: It transports cholesterol and other fats in the blood.
Energy Production
Proteins can be the energy source for the body in special situation. However, it is an undesirable situation as protein is a valuable nutrient that is widely used throughout the body.
The body breaks down skeletal muscles into amino acids to supply body functioning after 18 to 48 hours of fasting. The body will also do so if there is low carbohydrate storage.
Exhaustive exercise or inadequate calories intake may lead to this situation.
How Much Protein Do I Need?
The amount of protein that teenagers need is vary. It depends on different stages of development, heights, weight, gender and also level of activity.
1 gram of protein contains 4 calories.
Generally, teenager boys require 52 grams of protein per day, while girls require 46 grams per day. According to the American Academy of Pediatrics, teenagers between ages 11 to 14 require around 1.1 grams of protein per kilograms of body weight daily. Therefore, a young teenagers weighting 50 kilograms needs about 55 grams of protein per day. The amount of protein required per kilograms of body weight is slightly deceased in teenagers between ages 15 to 18, and it should make up about 10-12% of daily calories.
We obtain proteins from different food sources. Generally, animal-based food sources contain all 9 essential amino acids, which we called Complete Protein, such as eggs, fishes, beefs and porks. The plant-based food sources, except soy protein, that lack one or more of the 9 essential amino acids called Incomplete Protein, such as nuts, mushrooms and broccoli.
Conclusion
Proteins have many roles in the body. It is important to obtain sufficient amount of proteins in our diet in order to maintain our body's functioning. You can use common sense or nutrition label to estimate your protein intake. For example, an 8-oz glass of milk contains about 8 grams of protein. It is more effective than weighting every gram on the scale.
LET'S START A HEALTHFUL PROTEIN DIET!