Digestion – proteins are denatured
by hydrochloric acid in the
stomach
Body creates all of its proteins
from 20 different amino acids
Figure
Figure
Figure
Figure
Amino acids are absorbed in the small intestine
 Amino acids are transported to the liver from the
intestines via the portal vein
 In the liver, amino acids are
 Used to synthesize new proteins
 Converted to energy, glucose, or fat
 Released to the bloodstream and transported to cells
throughout the body
 Occasionally proteins are absorbed intact

 Functions







of protein
Provide structural and mechanical support
Maintain body tissues
Functions as enzymes and hormones
Help maintain acid base balance
Transport nutrients
Assist the immune system
Serve as a source of energy when necessary
Structural protein – collagen helps build bones
- ligaments that bind them
- tendons that connect them to the muscles
New growth and repair
They make up enzymes for helping chemical reactions
They make up antibodies in the immune system
Supply energy
Without these
particular structural
proteins, we would
look more like this….
Proteins are made of long chains
(polymers) made of monomers. All
proteins are made of the monomer…

Body creates all of its proteins from 22 different
amino acids
 13
are manufactured
 9 are essential amino acids – body needs
them but cannot make them
 Complete



proteins
Contain all nine essential amino acids
Usually animal source are complete proteins
Are considered higher quality
 Incomplete


proteins
Low in one or more essential amino acid
Usually plant sources are incomplete
 Complete
proteins
contain amounts of
all nine essential
amino acids.
SOURCES INCLUDE:
*Fish, meat, poultry,
eggs, milk,
cheese, yogurt,
and many
soybean products.
 Incomplete
proteins
 lack one or more
essential amino
acids.
SOURCES
INCLUDE:
*Beans, peas,
nuts, and whole
grains.
Vegetarian Diets-Reasons
Health
Religion
Ethical
Environmental
Taste
Vegetarians must
consume adequate
amounts of a variety
of food and should plan meals well




Vegetarian diets can be a healthy eating style that
may help reduce the risk of some chronic disease
Some vegetarians abstain from all animal products
Some vegetarians eat eggs and dairy in limited
amounts
Vegetarians must plan their diets carefully to meet
their nutrient needs, especially
 Protein
Riboflavin
 Iron
Vitamin B
 Zinc
Vitamin A
 Calcium
Omega-3 fatty acids
 Vitamin D
12
Potential
risks of a vegetarian
diet
 Underconsumption of certain
nutrients
Protein
Vitamin B12
 Vegetarian
Meat
 reduced
 growth






risk
obesity
diabetes
hypertension
heart disease
digestive disorders
cancer
eaters
 support
during
critical times.
A
teen female whose ideal body mass is 55 kg
needs about 44 g of protein a day

(55kg X 0.8 g/kg = 44 g)
Determine your RDA (0.8 gram/kg)

0.8 gram/kg

0.9 for males under age 18
 wt
in lb/2.2 lb per kg)x0.8=RDA