Chapter 17
Protein Functions in the Body (4:02)
http://www.youtube.com/watch?v=T500B5yTy58
Large and complex molecules
Made of hydrogen, carbon, oxygen, nitrogen
Often called macromolecules because of their
large size containing many atoms.
Nitrogen is a crucial part of protein, gives
proteins their variety and versatility
 Made from chains of amino acids
Amino acids consists of two groups
 Carboxyl group, carbon bonded to oxygen by a double
covalent bond, and to a hydroxyl group with a single bond
(-COOH)
 Amine group, two atoms of hydrogen and one atom of
nitrogen (-NH2)
Glycine – simplest amino acid
Peptide Bonds, bonds
between nitrogen of one amino
acid and the carbon of a second
amino acid
Polypeptide, a single protein
molecule containing ten or
more amino acids linked in
peptide chains
Shape determines the proteins function.
Fibrous protein form rope-like fibers,
this structure strengthens them to serve as
connective tissue in the body such as
collagen, hair, skin and nails.
Globular proteins form a rounded shape,
this structure makes them convenient
carriers such as hemoglobin.
Protein Denaturation (3:44)
http://www.youtube.com/watch?v=v2-iY7ZoDOc
Denaturation is a process of changing the shape of a protein
molecule without breaking its peptide bonds.
Coagulation changes a liquid into a soft, semisolid clot or solid
mass.
Heat – most common
Freezing, pressure, sound waves
and addition of certain compounds
Mechanical treatment (beating
eggs, kneading dough)
How to Knead Dough (2:45)
http://www.youtube.com/watch?v=ySOj0fFWo1U
Very high or very low pH (adding
lemon juice)
Metal ions, (Sodium, potassium,
copper and iron)
Eggs – contain almost every vitamin and mineral you need
Meat – contains fibrous proteins called actin and myosin. These
proteins form bundles of fibers, which are held together by
connective tissue made of collagen and elastin, two proteins with
long, strong molecules. Cooking meat is more complex due to
variations in fat and types of muscle fibers and connective tissue.
Fish – contain shorter, segmented muscle fibers that are layered
between thin sheets of connective tissue. Takes less time to cook.
Nuts and Legumes – carry lots of nutrients, cholesterol free but
fat content ranges from zero to very high.
Soybean proteins are equal to that in foods from animals.
oEmulsifiers – keep foods blended together. Ex:
salad dressing, mayonnaise
oFoams – air bubbles incorporated and trapped in
a protein film by whipping. Foam adds volume and
lightness to a recipe
oGelatin – animal protein used to set desserts and
thicken meat sauces
oGluten – an elastic substance formed by mixing
water with the proteins found in wheat, gives
baked goods their structure and shape.
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Structural protein is needed for every cell in the
body. Collagen helps build bones, the ligaments that
bind them, the tendons that connect them to
muscles, and the muscles themselves.
New Growth – replace and repair cells
Enzymes and hormones that are responsible for
body processes. (hormones aid in growth, balance
fluid, regulate metabolism)
Transports nutrients in cells. (lipoproteins, oxygen)
Antibody proteins help ward off disease
Stabilize pH levels
Supply energy if needed

Essential Amino Acids you need
to eat every day.

They come from animals source.

Soybeans are the only plant
source that provides them
• Unfortunately these contain
saturated fat and cholesterol

Complete Protein –
supplies all 9 “essential”
amino acids

Incomplete Protein –
lacking one or more
essential amino acids
› Meat
› Plant sources, must be
› Fish
eaten in greater variety
› Poultry






› Dairy (milk, cheese, yogurt)
› Eggs
› Soy
Different Types of Proteins ( 3:07)
http://www.youtube.com/watch?v=DRHCVQEIAwc
Rice with beans
Legumes
Nuts
Seeds
Grains
vegetables

Depends on…
› Age
Gender
Body size
Activity level
 Children, pregnant women, and nursing mothers
need higher levels
Food


Multiply your weight by 0.36
to estimate how many grams
of protein do you need each
day?
Example if you are 130 lbs.
You would need 47 grams
(130 X 0.36 =46.8)
Grams of protein per serving
Tuna (3 ounces)
22
Hamburger (3 ounces)
21
Chicken (3 ounces)
21
Shrimp (3 ounces)
18
Tempeh (½ cup)
15
Yogurt (1 cup)
11
Tofu (½ cup)
9
Lentils, cooked (½ cup)
9
Cow's milk (1 cup)
8
Peanut butter (2 tbsp)
8
Kidney beans, cooked
(½ cup)
8
Cheese (1 ounce)
7
Egg, cooked (3 ounces)
7
Soy milk (1 cup)
6
Hummus (1/3 cup)
6
Miso (2 tbsp)
4
Quinoa (½ cup)
4
Bulgur, kasha, oats,
cooked (½ cup)
3

Growth Failure

Loss of Muscle Mass

Decreased Immunity

Weakening of the
Heart & Respiratory
System
To much protein will
mainly cause
dehydration
 Loss in calcium and
vitamin B
 Which can lead to
other mental and
physical conditions


Brain is made up of
10% protein