ch 5 nutrition

what does protein mean

of first rank

what are proteins composed of?

carbon, hydrogen, oxygen, nitrogen

how much of the cell is protein

50% (most plentiful next to water)

Some proteins are working molecules (6)


�Antibodies �Transport vehicles �Hormones �Cellular �pumps� �Oxygen carriers

� Some proteins are structural molecules(7)

�Tendons �Ligaments �Scars �Fibers of muscles �Cores of bone and teeth �Filaments of hair �Materials of nails

Hair, nails and outer skin
made of

scleroprotein (non digestible)

Where else is protein


fxn of protein

�Builds new cells �Maintains tissues �Synthesizes new proteins

?% of protein eaten daily goes into
making enzymes that
�Digest food
�Assemble or divide molecules


made of amino acids
and nucleic acids


a protein from which connective
tissues are made


Structure of amino acids

amine groupacid groupside chain

Side chains Make the amino acids differ in 4

� Size � Shape � Electrical charge (+, -, 0) � behavior

cannont be synthesized by the body...must be aquired by food

Fully indepsensible amino acids

9 fully indespensible amino acids

� Histidine � Isoleucine � Leucine � Lysine � Methionine � Phenylalanine � Threonine � Tryptophan � Valine

5 Dispensable Amino Acids
�Synthesized by the human body

�Alanine �Aspartic acid �Cystine �Glutamic acid �Serine

Amino Acids that are essential in
the diet during certain stages of
development or in certain
nutritional or disease states

�Arginine �Cysteine �Tyrosine �Glutamine �Glycine �Proline

Sufficient amounts of the 9 EAAs to
maintain nitrogen balance

High Quality Protein

Balance of reactions in which proteins are broken down or destroyed and rebuilt

� Nitrogen Balance

Measure of how well food proteins can be converted into body proteins

� Biologic Value

Sustains optimal growth because have
all 9 IAAs present
� Animal sources (meat, fish, milk, eggs) � Soy

� Complete Proteins

�One or more IAAs missing in a food
�Supports life, but not normal growth
� Legumes, nuts, grains

� Low-Quality Proteins

single amino acid chanis are called


normal pH of the stomach


How Much Protein Do We Need?

�Depends on body size �For adults: 0.8g/kg body weight/day �Minimum: 10% of total calories �Maximum: 35% of total calories �Infants, children, pregnant women and athletes may need slightly more

Groups at risk for protein deficiency:

�Children of low socioeconomic rank �Chronically ill �Hospitalized patients �Elderly living alone or institutionalized

Even a single event of proteinenergy
malnutrition in the first
year of life can lead to

�delayed deciduous tooth eruption �delayed loss of primary teeth �increased number of caries

� Protein-energy malnutrition (PEM)

�World�s most widespread malnutrition �Includes both Marasmus & kwashiorkor �Adult PEM is often associated with longterm drug and/or alcohol abuse �a.k.a. Protein-Calorie Malnutrition (PCM)

? children
face starvation and suffer
the effects of severe
malnutrition and hunger

Over 500 million

�Chronic inadequate food intake
� Inadequate energy (calories), vitamin,
mineral, and protein intake
�Person is shriveled and lean all over

� Marasmus

�Swollen belly and skin rash are present
�Severe acute malnutrition
� Too little high-quality protein to support body
functions (IAA deficiency)
� Develops when a child is weaned from breast
milk to a low-nutrient diet

� Kwashiorkor

Too much protein may cause health risks for (3)

heartkidneybones (too much protein, body excretes Ca)

for vegitarians what should be monitored


What might you need to supplement for vegitarians

B12Vit D


�Dairy and plant foods �No meat, poultry, fish, eggs

�Lacto-ovo vegetarian

�No meat, poultry, fish


�Plants and eggs only �No meat, poultry, fish, dairy

�Vegan (strict)

�Only plant sources

� From protein energy malnutrition
� Depressed immune responses,
stress, infection
� Erythema
� Necrosis
� Cratered papilla


� Severe gangrenous process
� Starts as small gingival ulcer
� Becomes necrotic and spreads to
lips, cheeks, jaw tissues
� Lowered immune response

� Noma