1. Protein
Ch 7 Notes
Mrs. Brown

2. Composition Large, complex structure
Each molecule is made up of smaller units called amino acids
Amino acids are the building blocks of protein
They are water-soluble and can easily pass through the walls of the intestine

3. Composition There are 20 common amino acids
They are arranged like beads in a necklace in many different sequences to form proteins
It is like the using letters to form words
Depending on how you use the letters and how many letters you use you get different words

5. Essential Amino Acids Valine Lysine Leucine Isoluecine Methionine
Phynylalanine
Tryptophan
Threonine
Also Essential for Children
Arginine
Histidine

6. How are proteins formed?
When different amino acids are joined/linked together
These form 3D chains called polypeptide chains

7. Sources Meat (beef, chicken, bamb, pork, etc) Fish Eggs Milk Cheese
Animal
Plant
Meat (beef, chicken, bamb, pork, etc)
Fish
Eggs
Milk
Cheese
Yogurt
Soybeans
Nuts
Legumes
whole grain cereals, bread, potatoes, rice

8. Types of protein Albumin-meat muscle fibers, eggs, egg whites
Casein-milk and cheese
Gelatin-bones of animals
Gluten- flour

9. Denaturation
Change in the nature of protein-a breakdown of its structure
Generally occurs during food preparation
Heated
Physical agitation
Chemicals are added

10. Heat Protein coagulates Egg yolk/white solidifies
Milk forms a skin on top
Meat changes color
Connective tissue dissolves in moist heat to form gelatin

11. Agitation
Whipping or shaking
Egg white is whipped it changes to foam

12. Addition of chemicals
Acids, alkalis, alcohol, and enzymes may cause denaturation
Lemon juice or vinegar curdles milk
Rennin clots milk in cheese making

13. Function of Proteins
Building, maintaining, and repairing tissues (especially bone and muscle)
Can be used as an energy source
Make important compounds
Regulate mineral and fluid balance
Maintain acid-base balance
Carry vital substances

14. Quality of Protein
Complete proteins
Incomplete proteins
Contain all the essential amino acids in the correct proportion have a high biological value (HBV)
Usually from animal sources
Proteins which are deficient in one or more of the essential amino acids are known as low biological value (LBV)
Usually from vegetable sources

15. Complementation
Many proteins have the ability to make good the deficiency of another
i.e. at one meal, a person may eat a food which is low in one amino acid along with a food which is a good source of this amino acid
The two foods combine to give al the essential amino acids
This is how a vegan can stay healthy on a totally vegetarian diet

16. Complementary proteins
Combine these two foods
Legumes
Nuts, seeds, and grains
Dried beans
Dried peas
Lentils
Peanuts
Soy products
Barley
Oats
Corn
Pasta
Rice
Whole grain bread
Almonds
Cashews
Walnuts
Pecans
Sesame seeds
Sunflower seeds

17. How much protein do you need?
Recommended Dietary Allowance for Protein
Grams of protein needed each day
Children ages 1 – 3 13
Children ages 4 – 8 19
Children ages 9 – 13 34
Girls ages 14 – 18 46
Boys ages 14 – 18 52
Women ages 19 – 70+
Men ages 19 – 70+ 56

18. In general, it's recommended that 10–35% of your daily calories come from protein. Below are the Recommended Dietary Allowances (RDA) for different age groups.

19. Protein needs are determined by:
Age
Body size
Quality of the proteins
Physical state of the person

20. Here are examples of amounts of protein in food:
1 cup of milk has 8 grams of protein
A 3-ounce piece of meat has about 21 grams of protein
1 cup of dry beans has about 16 grams of protein
An 8-ounce container of yogurt has about 11 grams of protein

21. What happens to excess protein?
If more protein than necessary is consumed the excess is broken down by the liver and stored as energy (fat)

22. Vegetarians Vegans—consume foods only from plant
Lacto-vegetarian—eat foods from plant sources and dairy products
Ovo-vegetarian—eat foods from plant sources and eggs
Lacto-ovo
Semi-vegetarian—eat no read meat, but eat poultry and seafood

23. Too Much Protein Liver and kidney problems Calcium loss
Excess body fat

24. Protein Deficiency
Kwashiorkor-Kwashiorkor- Kwashiorkor occurs mostly in developing nations whose people lack foods high enough in complete protein. It generally strikes children from 1 to 3 years old, and it can be fatal.
Kwashiorkor stops or slows down a baby's growth. In severe cases, the muscles waste away, and the skin swells with body fluids. The child becomes extremely listless and resents any kind of disturbance, even feeding. As the disease progresses, the skin loses its natural color and may develop dark patches. Kwashiorkor also damages the liver and the small intestine, and it may cause black hair to turn reddish-brown. Many victims suffer anemia and show some vitamin deficiencies

25. Marasmus-muscles begin to waste away
Children become thin, weak, and susceptible to infection and disease