Proteins are composed of amino acids and are essential for building body tissue, regulating functions, and providing energy. There are essential amino acids that must be obtained through diet and nonessential ones that can be produced by the body. Important protein sources include meat, fish, eggs, and dairy. Insufficient protein intake can lead to muscle wasting, edema, and protein-energy malnutrition conditions like marasmus and kwashiorkor characterized by thinness and edema respectively. The recommended daily diet breakdown is 50% carbohydrates, 30% fats, and 20% proteins.

2. Objectives
1- State the functions of proteins in the
body.
2- Identify the elements that make up
proteins.
3- Describe the effects of protein
deficiency.

3. Proteins
Definition:
Are large biological molecules consisting
of one or more long chains of amino acid.
That means (Proteins are composed of
amino acids.)

4. Amino Acid
Amino acids are nitrogen-containing
compounds.
Amino acids are divided in to two:
1- Essential amino acids
2- Nonessential amino acids

5. 1- Essential amino acids: are amino acids
that cannot produced by the body. And
must be provided by the diet, that is whey
called essential.

6. Essential Amino Acids list:
1- Arginine (essential in childhood only)
2- Histidine (essential in childhood only)
3- Isoleucine
4- Leucine

7. 5- Lysine
6- Methionine
7- Phenylalanine
8- Threonine
9- Tryptophan
10- Valine

8. 2- Nonessential amino acids: are amino
acids that can be produced by the body.

9. Nonessential Amino Acids list:
1- Alanine
2- Asparagine
3- Aspartic acid
4- Systeine

10. 5- Glutamic acid
6- Glutamine
7- Clycine
8- Proline
9- Serine
10- Tyrosine

11. Sources of proteins:
1- Animal sources
- Complete proteins such as (meats, fish,
poultry, eggs, milk, and cheese)
2- Plant sources
Incomplete proteins such as (corn, grain,
nuts, sunflower seeds, sesame seeds)

12. Functions of proteins:
1- Building and repairing body tissue
2- Regulating body functions
Providing energy (each gram of protein
provides 4 calories(If no carbohydrates)).
3- Form hormones

13. 4- Form neurotransmitters for brain and
nerve function
5- Form other amino acids
6- Support immune function (help in
making antibodies)
7- Maintain fluid balance (control the flow
of fluids)

14. Types of Proteins in the Body:
1- Myosin: (muscle fibers)
2- Collagen: (bone, cartilage and skin)
3- Hemoglobin: (carries oxygen)
4- Albumin: (most abundant plasma
protein; serves as a carrier for drugs,
hormones, enzymes)

15. Digestion and Absorption of proteins:
1- Mechanical digestion
- Begins in mouth
- Teeth grind food into small pieces.

16. 2- Chemical digestion
- Begins in stomach through exposure to
acid and hydrolysis by enzymes called
proteases and pepsin.
- In small intestine by pancreatic enzymes
(trypsin, chymotrypsin, and
carboxypeptidase) continue chemical
digestion and absorption through the villi.

17. Metabolism and Elimination of proteins:
- Amino acids are broken down and the
nitrogen-containing amine group is
stripped off
- Ammonia is produced.

18. - Liver picks up ammonia and converts it to
urea.
- Kidney filters out urea and excretes it.
Protein stores are limited; can maintain the
body for only a short time

19. Dietary Requirements of proteins:
- Determined by size, age, sex, and
physical and emotional conditions.
- To determine your requirement:
1.Divide body weight by 2.2 (the
number of pounds per kilogram).
2.Multiply the answer obtained in the
first step by 0.8 (grams of protein per
kilogram of body weight).

20. Signs and symptom of protein deficiency:
- Muscle wasting.
- Albumin (protein in blood plasma)
deficiency causes edema.
- Loss of appetite, strength, and weight
- Lethargy, depression, and slow wound
healing

21. Protein Energy Malnutrition (PEM)
a- Marasmus:
- Affects very young children
- Results from severe malnutrition (lack of
energy, protein, vitamins, and minerals)
- thin, no edema
- Hair is dull and dry; skin is thin and
wrinkled
6-21

22. Marasmus

23. b- Kwashiorkor:
- Lack of protein-containing food
- affects children and adults
- lack of protein and hormones results in
edema.
- painful skin lesions, and changes in
pigmentation of skin and hair
- High mortality rate

24. Kwashiorkor

25. Conclusions
Recommended Amounts in Daily Diet:
- Carbohydrates - 50%
- Fats - 30%
- Protein - 20%

26. Thank