Co
nc
ep
ts
Living things are made of many
simple and complex molecules.
Chemical reactions in living things are
necessary for survival.
W
o
r
d
s
t
o
k
n
o
w
matter - anything that fills space and has mass
atom - a very, very small particle that makes up all
matter
molecule - a small particle made of two or more
connected atoms
chemical reaction - an interaction of atoms or
molecules to form new elements or molecules
biochemistry - the study of chemical reactions
that occur within living things
protein - a complex molecule that may act as a
structural element or may assist biochemical
reactions; hair, nails, skin, meat are all proteins
amino acid - a small molecule that is a building block
of a protein; long chains of these make proteins
catalyst - a substance that helps chemical
reactions occur, but is not changed in the
reaction
enzyme - a protein that acts as a catalyst
sugar - simple biological molecule that provide
energy for living things
carbohydrate - a complex molecule made of many
sugars
DNA - DeoxyriboNucleic Acid; this complex molecule
carries genetic instructions for living things
acid - a compound that increases the number of
hydrogen ions (H+) in solution with water. All
acids have a pH below 7.
base - a compound that decreases the number of
hydrogen ions (H+) in solution with water. All
bases have a pH above 7.
pH - a scale that measures relative acidity and
basicity
indicator - a chemical that changes color with
changes in pH.
Use the
Words to Know
to complete the puzzle below.
Down
1. Cabbage juice, an _____, turns deep red in acidic
solutions.
2. A _____ helps a chemical reaction to occur but is
not changed during the reaction.
3. An enzyme is a special type of _____.
4. Pasta, crackers, popcorn, and bread are all
examples of a _____.
Across
5. _____ carries genetic instructions in all living
things.
6. _____ is the study of the chemical reactions of
living things.
7. Vinegar is an acid since its _____ is below 7
CheM LaB
Take-Home Activities
Biochemistry
This project funded by
© 2006 OMSI
Yeast Balloons
Egg Osmosis
Cabbage Juice Indicator
Can biochemistry blow up a balloon?
A four day eggsperience!
Test the pH of household products!
Materials:
Materials:
one small clear plastic soda bottle
warm water
one package active yeast
2 tablespoons sugar
one large balloon (8” or 9” size)
2 raw eggs in their shells
vinegar
corn syrup
water
two wide-mouthed jars, deep
enough to submerge the eggs
To do and notice:
1. Half fill the bottle with warm water.
• Why might hot or cold water not work?
2. Add the yeast and sugar to the
bottle.
3. Cap the bottle tightly and shake
it well.
4. Uncap the bottle and stretch
the neck of the balloon over the
bottle opening for a tight seal.
5. Sit back and watch. After about
20 minutes you should see the
balloon begin to inflate. This
process will continue over the
course of several hours.
• Why does the balloon inflate?
A closer look:
Yeast are tiny organisms that live well at warm
temperatures. The yeast will die in water that is too hot,
and will not be active in water that is too cold.
Yeast use sugar as food. In a biochemical
reaction called “fermentation,” the yeast breaks down
the sugar (C12H22O11) into ethyl alcohol (C2H5OH) and
carbon dioxide gas (CO2). The carbon dioxide gas creates
© 2006 OMSI
Materials:
CAUTION: Always wash
your hands thoroughly
with soap after handling
raw eggs, which are a
common source of
salmonella bacteria.
To do and notice:
Days 1-2
Put the eggs in a jar. Cover the eggs with
vinegar. Keep the eggs in vinegar for two
days. Look for changes on the surface of the
egg during the two days. As the egg shell
reacts with the vinegar, the reaction produces carbon
dioxide gas bubbles.
• What happens to the shells?
Day 3
Carefully remove each egg from the
vinegar. Rinse the eggs and the jars with
water. Gently feel the eggs.
Put one egg in each jar. Cover one egg
with water and cover the other egg with light corn syrup.
Let the eggs sit overnight.
Day 4
Observe both eggs (you can gently pick them up).
• What are the differences between them?
A closer look:
The membrane around the egg is like a very fine
mesh. Small molecules like gases and water can pass
through the membrane, but larger molecules like proteins or
sugars cannot. When water passes through the membrane,
this is called “osmosis.”
Corn syrup is a very concentrated solution of large
molecules. When the egg is in corn syrup, water from inside
the egg flows out to dilute the corn syrup. The egg shrivels.
In water, solution inside the egg is more concentrated than
the water outside. The water flows into the egg in an
attempt to dilute the white of the egg. This makes the egg
swell up to its full size.
large pot half full of water
water
½ head of RED cabbage
chopping knife or food processor
strainer
large bowl
spoon
plastic cups
baking soda
vinegar
To do and notice:
1. With an adult’s help, heat the pot of water until the
water is very hot.
2. With an adult’s help, chop the cabbage with a knife or
food processor.
3. Place the cabbage pieces in the pot and cover them
with the hot water. Let the cabbage pieces sit for 2
minutes in the hot water.
• What happens to the color of the water?
4. Place the strainer in the
bowl. Pour the cabbage
pieces and cabbage juice
through the strainer,
collecting the juice in the
bowl.
5. Use the spoon to put cabbage juice in some plastic
cups. Add a few drops of vinegar to one of the cups.
• What color is the mixture?
6. Add some baking soda to another of the cups.
• Is the color different?
7. Find other things to add to the cabbage juice.
Examples might include milk, lemon juice, soda water,
soap, antacids, and aspirin.
A closer look:
Red cabbage contains a chemical that changes its
shape depending on whether it is surrounded by an
acid or base. When its shape changes, so does its
color. The cabbage juice is purple in water (neutral), red
in vinegar (acid) and blue-green in baking soda (base).
Some other plants also have chemicals that
change color. Try this with flower petals, juices, or
berries.