PROTEINS
PROTEINS ARE FOUND IN…
Animal Sources:
Plant Sources:
PROTEIN
without proteins, life could not exist
proteins contribute to ________________ and __________________________
proteins help the body _______________________________
STRUCTURE OF PROTEINS
Proteins make up _________ of your body’s total weight
Proteins are in every cell and all tissues and organs
Proteins may be very small, but they are very complex
Proteins are made from chemical building blocks that are called ___________________,
which link together in many different arrangements
AMINO ACIDS
When amino acids chain together to make proteins, they take different ___________
…Shape determines function
long rope-like spirals…form tendons and ligaments
globular, folded shapes…carries chemical compounds
Hemoglobin—transports oxygen in the blood to all cells in your body
PROTEIN DIGESTION
After you eat a protein food, your body breaks the protein down into amino acids
Then, the amino acids can be reassembled as human body protein
protein digestion begins in the __________________
strong stomach acids change the shape of the proteins and stomach
enzymes break the protein down more
protein digestion continues in the small intestine until individual amino acids
become available
the amino acids can then be ______________________ into the bloodstream
upon reaching the cells, the amino acids are used to make proteins for specific
purposes
ESSENTIAL AMINO ACIDS
Your body makes many amino acids for itself.
Even in healthy people however, the body can’t make some amino acids or can’t make
them in _________________________________
The amino acids that your body needs but cannot provide are called ________________
AMINO ACIDS
You must get these essential amino acids from _____________
COMPLETE PROTEINS
Some protein foods contain all the essential amino acids.
Since foods from __________________ sources have them all, they are known as
COMPLETE PROTEINS
INCOMPLETE PROTEINS
Foods from ________________ sources lack at least one essential amino acid
Therefore plant proteins are called INCOMPLETE PROTEINS
The ONLY exception is __________________ which are a complete protein
Dry beans, peas, lentils, nuts, and seeds have nearly all the amino acids
Grains and many veggies are missing more of them
WHAT IF I DON’T EAT MEAT?
If you don’t eat foods from animal sources, you need to get all the essential amino acids
from incomplete proteins.
By choosing a ______________ of plant foods, especially grain products, dry beans and
peas, and nuts and seeds, vegetarians can get what they need….what is missing in one
plant food, you can get by eating another.
THE NEED FOR PROTEIN
growth and maintenance
enzymes
hormones
antibodies
fluid balance
GROWTH AND MAINTENANCE
In children and young adults, new cells are needed for growth
__________, eyes, skin, teeth, _______________, and bones are all made up of
proteins…the proteins you eat help keep all of these in good condition
Most proteins in a healthy body are constantly broken down and ________________
new skin cells from beneath the surface constantly replace old cells, the cells in
your intestinal tract live for only a few days needing regular replacement, people
who are ill need new cells to replace damaged ones
ENZYMES
__________________ reactions are constantly going on in the cells of your body.
Without the special proteins called enzymes, these reactions couldn’t take place at the
necessary rate
HORMONES
Hormones are chemical _________________ that help regulate conditions in the body
Some hormones in the body are made from amino acid
the thyroid hormone regulates body metabolism
insulin helps maintain the level of glucose in the blood
ANTIBODIES
Antibodies are proteins that ________________________…the body creates them
when a need arrises
proteins play a major role in fighting disease
if you get the flu…your body makes antibodies to fight it…if you get the same
strain of flu again, your body ‘remembers’ what to make and fights off the illness
more quickly
FLUID BALANCE
a cell’s life depends on having _____________ in the right amount…too much fluid
causes cells to rupture and too little stops their activity
cell’s cannot move fluid directly, so they they build proteins inside cells to
__________________ water, and they send proteins into the blood stream to maintain
fluid levels there
ONE MORE NEED…
Normally proteins provide very ____________ energy
but, if you don’t eat enough carbs and fats to meet your energy needs, your body will
use proteins for energy
However, this means that then the _______________________ of the proteins doesn’t
get done
HOW MUCH PROTEIN DO YOU NEED???
Teens should get ____ to ____% of their calories from proteins
Adults should get 10 to 35% of their calories from proteins
A larger person needs ____________ calories than a smaller person
During certain periods in life, a person’s need for proteins is higher
___________________________________ and nursing mothers need extra
protein to build new cells
infants, children, and _____________ need protein to help them grow
when people are ill or injured, proteins help rebuild damaged cells
EXCESS PROTEIN
protein is essential, but too much protein can be _____________________
excess amounts are broken down and stored by the body as ___________
if you eat huge amounts, your body must work overtime to break down the extra
protein and remove the byproducts
healthy people don’t need protein or amino acid _____________________
most people get plenty of protein by choosing a ______________________________
INADEQUATE PROTEIN
although getting enough protein is not typically a problem for people in developed
countries, it’s a serious problem in other parts of the world
Protein-energy malnutrition (PEM) is a leading form of malnutrition in the world…with
PEM they lose weight and don’t grow properly…some die of starvation
even in developed countries, PEM can affect people who have _______________
_______________ or drug addictions
PROTEIN FOOD CHOICES
Most Americans get the largest amount of their protein from _________________
sources
Health experts recommend however that people get more of their protein from
_____________ sources
plant sources generally have less __________ and usually cost less too