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Protein Structure



Primary - sequence of amino acids
Secondary – folding into pleated
sheets or alpha helix
Tertiary – 3-D structure, completely
folded


Most proteins stop here
Quaternary – interaction of several
protein molecules

Hemoglobin
2-4 Chemical Reactions and Enzymes

Enzymes
 biological
catalysts

Speed up reactions
 Without them
reactions would
occur too slow for
life
 Lower the activation
energy
Enzymes

Enzymes provide a site where substrates can
be brought together = Active Site (tertiary)
 The fit is like a lock and key
Enzyme Regulation

Work best at a
particular pH


Affected by changes
in temperature


Digestion enzyme
Denaturization
Concentration
p. 51
Suggest an
explanation for the
change at 40 sec. in
the control.
How does the base
affect the enzyme?
How does the acid
effect the enzyme?