Name ______________________________________
Table _____ Period _____ Score: _____/
Denaturation Tests
Understand denaturation of protein & its causes and effects.
Write inferences based on observations.
Denaturation
Organic
Solvent
Base
Acid
Ionic
Compound Agitation
Heat
Control
Denaturation is a change in the _______________ of a protein that does not break its covalent bonds, but does change the nature of the protein.
Note your observations as students perform each test. Note that proteins do not all react the same to denaturing agents.
Agent
Test
With 1 T. egg white
With milk
What do you observe about the untreated
egg and milk? Color, texture, etc.
Egg--Place the egg on a hot frying pan
and cook until solid.
Milk: Heat ¼ c. milk on the stove. Stir
constantly. Turn off at first sign of boil.
Egg--Place the egg in a bowl and beat 35 minutes.
Milk: Pour ¼ c. milk into a small bowl.
Beat 3-5 minutes
Egg: Put 1 T. egg white in a clear cup.
Stir in 1 t. salt. Keep adding salt until
you notice a change.
Milk: Do same test using 2 T. of milk
Egg: Put 1 T. egg white in a clear cup.
Stir in 1 t. lemon juice
Milk: Do same test using 2 T. of milk
Egg: Put 1 T. egg white in a clear cup.
Stir in 1 t. baking powder. Keep adding
baking powder ½ t. at a time until you
notice a change.
Milk: Do same test using 2 T. of milk
Egg: Put 1 T. egg white in a clear cup.
Stir in 1 t. rubbing alcohol. Keep adding
baking powder ½ t. at a time until you
notice a change.
Milk: Do same test using 2 T. of milk
Observations:
1. What are some of causes of
denaturation that you observed in
this experiment?
2. What are some effects you
observed that were caused by the
denaturation?
a.
b.
c.
d.
e.
a.
b.
c.
d.
3. Which nutrient does
denaturation happen to?
carbohydrate? protein? fat?
4. Name 4 foods that are high in
a. ____________________ b. ___________________ c. ___________________ d. ___________________
that nutrient.
4. Jello gels because it contains
protein in the gelatin. What do you
think might happen if you put very
acidic pineapple in your Jello?
5. If heat denatures protein, do you
think it is better to use low/medium
heats, or medium/high heats for
most proteins?
Write a paragraph about what denaturation of protein is, and some of its causes and effects.
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