Date _____
Part 1: An Edible Slime (Polymer)
Seaweed Lab
Name ___________________
The polymer that we will be making is formed by mixing two chemicals: sodium alginate and calcium chloride.
The alginate comes from brown seaweed (kelp). The alginate is a polymer because it is made from many units of
glucose (a type of sugar).
When we add dissolved calcium chloride to dissolved sodium alginate we get a new substance called calcium
alginate, which does not dissolve in water, thus forming an edible slime.
Procedure:
1. Dissolve __ spoonfuls of calcium chloride in the clear cup full of warm water.
2. Fill the other paper cup with warm water. Add a spoonfull of your favorite Kool-Aid mix and __ of a
spoonful of sodium alginate. Stir vigorously for at least 3 minutes until most of the sodium alginate is
dissolved in the water. The mixture should become very viscous.
3. Slowly pour the sodium alginate mixture into the calcium chloride to make a worm or add it one drop at a
time to make little spheres.
Part 2: Human Uses of Seaweed
There are 3 major groups of seaweed: brown, red and green algae. Alginate (used to make the slime earlier)
comes from brown algae. Carrageenan is a generic term to describe anything that has been extracted from red
algae. Finally, beta carotene is a common ingredient that comes from green algae.
Procedure:
Around the room you will find several product packages. Read the ingredients of each product to
determine what type of seaweed is in the product. Use the table below to organize the products based
on the seaweed they contain.
Brown Algae
(Alginate)
Red Algae
(Carrageenan)
Green Algae
(Beta Carotene)
What do these products have in
common?
What do these products have in
common?
What do these products have in
common?
Date _____
Seaweed Lab
Name ___________________
1. Looking at the data in the table above hypothesize about the role of each of the seaweeds in the products.
Alginate: Alginate was added to the products because it____________________________________________
_____________________________________________________________
_____________________________________________________
_____________________________________________________________
Carrageenan:
____________________________________________________
_____________________________________________________________
Beta Carotene:
2. Based on the products observed in this lab would you say that algae is essential for the survival of
humans? Explain your answer.
_____________________________________________________________
_____________________________________________________________
3. Is algae essential for the survival of animals living in most marine ecosystems. Explain.
_____________________________________________________________
_____________________________________________________________
4. Explain why algae are usually found growing in the shallow waters just off the coast.
_____________________________________________________________
_____________________________________________________________
5. Scientist always assumed that there could be no life at the bottom of the ocean because there is no
light for photosynthesis. Recently scientists were shocked to find life at the deepest part of the ocean
where it is pitch black. What are the primary producers in this deep sea ecosystem and how do they
get their energy without light?
_____________________________________________________________
_____________________________________________________________
Date _____
Seaweed Lab
Name ___________________
Carrageenan are used in stabilizing and gelling foods, cosmetics, pharmaceuticals, and industrial products.
Alginates make water-based products thicker, creamier, and more stable over extreme differences in
temperature, ph, and time. For example, alginates prevent ice crystals from forming in ice cream.
Beta Carotene, a natural pigment derived from green algae, is used as a yellow-orange food coloring and may
help prevent certain types of cancers.
Teacher Key:
!-carrageenan
@-alginate
#-beta carotene
Product Containing Algae ! @ #
Brownie mix ! @
Cheese (yellow and orange) #
Chocolate milk !
Coffee creamer ! #
Cottage cheese !
Egg substitute #
Evaporated milk !
Frozen foods and desserts @ #
Frozen yogurt !
Ice cream ! #
Infant formula !
Margarine #
Mayonnaise #
Multiple vitamins #
Pet food !
Pudding (cooked) !
Relishes ! @
Salad dressing @ #
Sauces and gravies ! @
Sour cream !
Toothpaste !
Whipped topping ! #
Whipping cream !
Yogurt !