Transcript Proteins - Northwest ISD Moodle

Proteins
Protein (enzyme) that
breaks down insulin
What makes something a protein?
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Made up of Carbon (C), Oxygen (O), Hydrogen
(H) and Nitrogen (N)
Large polymers (proteins) made up of many
monomers = AMINO ACIDS
What is an AMINO ACID?
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The building block of proteins
R = “side chain”; variable in each of the 20
amino acids; makes each monomer unique
The 20
Amino
Acids
How are proteins formed?
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PEPTIDE BOND = holds proteins together
Proteins are sometimes referred to as
polypeptides for this reason
Proteins
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Hundreds to thousands of amino
acids hook together to form
proteins
Only 20 different amino acids
(“letters”) combine in MANY
different ways to form a variety of
proteins (“words”)
FYI 
Largest protein = Connectin
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important in contraction of striated
muscle tissue
34,350 amino acids long
Smallest protein = TRP-Cage
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saliva of Gila monster
20 amino acids long
Functions of Proteins:
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Structural material – hair, skin, muscle,
cartilage, blood, organs, etc.
Chemical controllers – ENZYMES (molecules
that speed up the rates of chemical reactions)
How do proteins differ?
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a) Number of amino acids:
C-A-T
C-A-T-C-A-T
b) Type of amino acids:
C-A-T
D-O-G
c) Sequence of amino acids:
C-A-T
A-C-T
d) Shape of molecule:
C-A-T
C-A-T
C-A-T
Protein Structure
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Proteins are made
linearly (in a line),
but they bend and
fold to form complex,
3-D structures
**Study structures to
the right!!**
How do you test for proteins?
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Nitric Acid Test
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Positive test =
turns yellow
Negative test =
remains clear
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Biuret Test
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Positive test =
turns purple
Negative test =
remains blue
Review!
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What type of bond holds amino acids
together?
What makes a protein different from a
carbohydrate or lipid?
How many different amino acids are
there?
How can you test for proteins?