Download Proteins

Characteristics
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Found in foods like:
Meat
Dairy (cheese, yogurt)
Nuts
Eggs
Beans
Characteristics
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Proteins make up cells, skin, hair, fingernails,
hormones, enzymes and antibodies (fight
infection)
Energy source BUT we don’t want to rely on it
Contain C, H, O, and Nitrogen…Some contain
Sulfur
Body digests protein into small units: Amino
Acids
Why are proteins digested into
amino acids???
1. Proteins in food are digested into amino
acids
2. Amino acids are small enough to travel
through the cell membrane.
(what will your cells do with the amino
acids?)
3. Inside cells, Amino
acids
are put
together in
New
proteins
needed
for your body
order to build….
Proteins digested Amino acids
in food
Joined together
to build
Proteins
for the
body
Structure of an Amino Acid
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There are 20 types of amino acids
All amino acids contain:
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1 carboxyl group (COOH)
1 amino group (NH2)
1 variable group (also called side chain, or R)
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Different in each amino acid
Structure of an Amino Acid
Dehydration Synthesis/Hydrolysis
Group Key
Carboxyl
Amino
Variable
http://www2.nl.edu/jste/proteins.htm
1.
2.
3.
Peptide Bond
-Bond between 2 amino acids
Dipeptide
-2 amino acids bonded by a peptide bond
Polypeptide
-3 or more bonded amino acids
-Large polypeptide = Protein
A
group of amino acids held
together form a protein

A group of amino acids held together
form a protein
Kwashiorkor on the increase in Zimbabwe
In some countries, children who do not get enough
protein develop large stomachs. Why?