Food Nutrition (Protein)

8/6/2019 Food Nutrition (Protein)

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PROTEIN

Lee Son

(Food Science and Technology)



What is Protein???Proteins are biochemical compounds consisting of

one or more polypeptides typically folded into aglobular or fibrous form in a biologicallyfunctional way.

Protein is a macronutrient that can provide the

body with energy (4 calories per gram).



S tructure Protein (Peptide bond)



Many foods contain protein, butthe best sources are beef, poultry,

fish, eggs, dairy products, nuts,seeds, and legumes like blackbeans and lentils.



Despite the fractious debate on low-fat, high proteindiets, protein remains an important element in our dietas it serves various crucial functions in the human body.

Protein makes up about 75 % of our body weight and isin our muscles, skin, bone, hair and every other part of our body. Composed of enzymes and amino acids ,protein provides the power source for chemical reactionsin the body and carries oxygen in the blood.



Forms of rotei

There are different types of protein :1. Complete protein2 . Incomplete protein



Complete proteins,usually found in animalsources such as meat,poultry, fish, eggs and

dairy, have all the aminoacids needed to developnew proteins. Thismeans eating a serving

of meat will provide yourbody with everything itneeds to make newproteins.

Incomplete proteins, foundin fruits, vegetables, grainsand nuts, lack one or more

amino acids. In order tomake up new proteins, it is

necessary to eat a varieddiet and/or use proteinsupplements. This is of

particular importance to

vegetarians and vegans,since almost all of their

protein sources will beincomplete.

Complete Proteins Incomplete Proteins



The Benefits of Protein

Protein is an important component of every cellin the body. Hair and nails are mostly made ofprotein. Your body uses protein to build andrepair tissues. You also use protein to makeenzymes, hormones, and other body chemicals.

Protein is an important building block of bones,muscles, cartilage, skin, and blood.



A DVANTAGES OF P ROTEIN

Foods that contain high levels of protein, tend to bedigested more slowly from the stomach to the intestine,thereby making you feel full longer. Additionally, protein hasa gentle stabilizing effect on blood sugar.There is evidence to support the claim that consumingprotein low in saturated fat, and cutting back on highlyprocessed carbohydrates improves blood triglycerides andhigh-density lipoprotein. These changes could reduce yourchances of heart attack, stroke, or other cardiovascular

disease.Protein-rich foods also offer healthy fibers and nutrientsthat are important in a well-rounded diet.A lack of protein in the diet can lead to growth loss,

weakening of the muscles, heart and respiratory system,decreased immunity and death.



Despite all the wonderful things protein does for youand your body, consuming too much protein can bequite bad for you.The human body can store only small amounts of excess

protein. During digestion, protein is broken down intoamino acids that the body uses for energy. Any aminoacids that are not used are converted into fat.The digestion of protein releases acids that the bodyneutralizes with calcium. Eating excess amounts ofprotein requires a great deal of calcium, which can beleached from bones. A protein-excessive diet on a long-term basis could significantly weaken bones.A high-protein diet, like Atkins may increase the risk ofkidney stones and osteoporosis.



Proteins have multiple functions. Very fewbiological reactions take place without the

involvement of one or more proteins. The table

below is only an arbitrary classification of proteins. It simply aims to illustrate the wide

range of roles of proteins.



Amino AcidsAmino Acids

Protein is made up of amino acids that alinked together. There are two main type

amino acids, essential ones and non-essential ones. Essential amino acids can

be produced by the body and must bebrought in through the diet. Non-essent

amino acids can be made by the body antherefore not required in the diet.



Amino Acids

Proteins are a chain of amino acids.There are 20 common amino acids.

Amino acids share a common structureexcept for one chemical group (R, sidechain) attached to the central carbonatom.



The 20 different R groups give amino acid individuacharacteristics. The sequence of different amino acids wgive each protein unique characteristics. The amino acid

grouped in four major groups according to theircharacteristics.



http://kidshealth.org/kid/nutrition/food/protein.html#Branden C, Tooze J (1999). Introduction to Protein

Structure . NewYork: Garland Pub. ISBN 0-8153-2305-0.

http://www.webmd.com/fitness-exercise/guide/benefits-proteinwww.agoodvitamin.comhttp://www.epigee.org/fitness/protein.htmlU.S. Department of Agriculture, News Release: Meatsand Alternates USDA Helps Find the Best Buys,August 1985.http://www.chemie.fu-berlin.de/chemistry/bio/amino-acids_en.html .

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