Protein structure and shape, denaturation and Enzymes for 9th graders.

1. PROTEIN SHAPE
PROTEIN STRUCTURE
AND
ENZYMES
Proteins Part II

2. Types of proteins
Essential, Nonessential, and
Conditional
Essential – must be consumed in the diet
Nonessential – can be synthesized in the body
Conditionally essential – cannot be synthesized due to illness or lack of
necessary precursors

3. Functional protein consists of one
or more polypeptides precisely
twisted, folded and coiled.
Denaturation is the
process in which a
protein unravels and
loses its normal
shape.
Changes in pH
and temperature

4. Bonds between amino acids (from monomers to
polymers)
chemical reaction: Dehydration
Reaction

5. Structure of the Protein Any
alteration
in the
structure
or
sequencin
g changes
the shape
and
function
of the
protein

6. Denaturing
Alteration of the
protein´s shape and
thus functions
through the use of
Heat
Acids
Bases
Salts
Mechanical agitation

7. Denaturing a Protein

8. ENZYMES
 Weaken chemical bonds.
 Molecules absorb energy.
 “start-up” energy is called
Activation energy.
 Heating up would cause
unnecessary reactions to occur at
once.
 Catalysts (compounds that speed up
reactions).
 Lowers the energetic requirement.

9. Lock and
key.
Specific
substrate
for the
enzyme.

10.  http://highered.mcgraw-hill.
com/sites/0072495855/student_view0/chapter2/animation__how_enzymes_w
ork.html

11. Quick Review
Proteins are chains of combination of amino acids
Amino acids contain carbon, hydrogen, oxygen, nitrogen, and sometimes
sulfur
Unique amino acids consist of a central carbon with a carboxyl group, a
hydrogen, a nitrogen-containing amine group, and a unique side chain
There are 20 side chains and 20 unique amino acids
9 essential amino acids
11 nonessential amino acids
At time these become conditionally essential
Amino acids link together with peptide bonds by condensation and break
apart by hydrolysis

12. Quick Review
Attractions and interactions between the side chains cause
the proteins to fold into precise three-dimensional shapes
Protein shape determines its function
Proteins are denatured and their shapes changed by
Heat
Acids
Bases
Salts
Mechanical agitation

13. Quick Review
Protein structure has 4 levels:
a)Primary structure
b)Secondary structure
c)Tertiary structure
d)Quaternary structure
 Denaturation is the Alteration of the protein´s shape and thus
functions through the use of
Heat
Acids
Bases
Salts
Mechanical agitation