Download Proteins - West Branch Schools

Proteins
 A protein is a compound made of small carbon
compounds called AMINO ACIDS
 There are 20 different kinds of AMINO ACIDS
Proteins continued…
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Proteins can have up to 4 levels of structure:
 1. The number of amino acids in a chain and
the order in which amino acids are joined
define the proteins primary structure.
 2. After an amino acid chain is formed, it
folds into a unique three-dimensional shape
 Helix and a Pleat
Proteins Continued…
3. Tertiary structure of many proteins is
globular, such as hemoglobin
 Denaturation is a process in which
proteins or nucleic acids lose the tertiary
structure and secondary structure
(unravel) Think of an egg!
 Change in temperature or pH can cause a
protein to unravel and change shape
 4. Some proteins form a 4th level of
structure(Quaternary) by combining with
other proteins.
Coloring Sheet…. Match the
letter to the picture with a
color
 Peptide Formation
 Primary Structure
 Helix
 Pleated Sheet
 Tertiary Structure
 Quaternary Structure
Proteins continued…
 A polypeptide is a chain of amino acids bonded
together by peptide bonds. Protein molecules consist
of one or more polypeptides.
 Protein function:
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Make up 15 percent of your total body mass
Muscles, Skin, and Hair are made of proteins
Help your cells communicate with one another
Speed up chemical reactions
Control cell growth
Activation Energy
The minimum amount of
energy needed for reactants to
form products in a chemical
reaction.
Enzymes
 Catalyst- is a substance that lowers the activation
energy needed to start a chemical reaction.
 It speeds up a reaction but does not increase how much
product is made
Enzymes- special proteins are the
biological catalysts that speed up the rate
of chemical reactions.
*Essential to life
Activation Energy
How do enzymes work?
 Enzyme has 2 parts (lock and Key)
 Substrate which is the reactant that binds to the enzyme
 Active Site specific location where the substrate binds
 The substrate and active site fit together like a puzzle piece
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EX. Hard Green apples ripen because of enzymes
Ex. Enzymes in a snakes venom break down membranes of
human blood cells