Wednesday, August 4, 2010

Cheek Cell DNA Experiment


1/4 teaspoon
8 ounce measuring cup
a small bowl
Dixie cup
pre-form bottles (test tubes)
a stirrer (skewers)
liquid dish soap
rubbing alcohol

Concept: Your DNA is found in your bllod, cheek cells, skin, and other various parts of your body. The white stringy layer you captured is your own personal DNA. Each string is composed o thousands of DNA molecules all stuck together. There are about 50 trillion DNA cells in your boday. You collected the cells from your cheeks. the dish soap broke down the cells realeasing DNA into the mixture. The salt combined with the DNA, and the DNA clumped together where the water and alcohol layers met.

Procedure: Dissolve 1 tablespoon of salt in 1 cup of water to make a 6% solution of NaC1 (chemical formula for salt NaC1). Salt is made up of sodium and chloride. The Na stands formsodium and the C1 stands for chloried. This will now the called NaC1 solution. Dilute the dish soap by mixing 1 tablespoon of soap with 3 tablespoons of water in your small bowl. This will now be called the detergent solution. Swish 1 tespoon (no tablesppon) of plain water around in your mouth vigorously, for at least 30 seconds. Then, spit it out into the Dixie cup. This will now be called the spit water. Put 1/4 teaspoon of your NaC1 solution into the test tube. Pour your spit water from the Dixie cup into the test tube with the NaC1 solution. Add 1/4 teaspoon of detergent solution to the test tube and place lid on test tube. Gently turn the tube upside down several times. Avoid making any bubbles. Take off the lid and dribble about 1 teaspoon of the rubbing alcohol down the side of the tube into the mixute. Look for the alcohol to form a layer on top of the spit/water/NaC1/detergent mixture. Did a white stringy layer form? Good. Now try and grab it with your stirrer. The gunk you see is your DNA. It contains some proteins, but is mostly your DNA. Scientist have figured out a way to read DNA codes. They can extract DNA from a drop of blood.

Extension: Fingerprinting is also used for identification. Have students use ink to make their fingerprints on paper. Then have students examine their fingerprints and compare to others. What is similar? What is different? What are your fingerprint patterns (arch, tentarch, loop, double loop, pocked loop, whorl, mixed)?

Application to Real World: DNA or deoxyribonucleic acid is a component of the human body. It is the building block for an individual's entire genetic make up. DNA is the same in every cell. DNA is different in every person with the exception of identical twins. DNA can be used to identify a victim and at a crime scene to link or eliminate a suspect. Environmental factors such as heat, sunlight, moisture, bacteria, and mold effect DNA.

Tuesday, August 3, 2010

Dirt Worm Dessert


large box of Jello chocolate pudding
Cool Whip
gummy worms
measuring cups
large Zip Lock bag

Concept: To inquire the sense of taste into a delicious experiment. Have the students compare and contrast their dirt worm dessert to real dirt and worms.

Procedure: Mix a large box of chocolate pudding with 3 cups of milk. Stir until well mixed and let stand for 5 minutes to allow pudding to set. Add in a regular size container of frozen Cool Whip. Crush a row of Oreos in the large Zip Lock bag. Mix a 1/2 cup of the crushed Oreo's into the bowl with the pudding and Cool Whip mixture. Spoon your treat into clear plastic cups, sprinkling with crushed Oreos and then placing gummy worms on top. Bon Appetite!

Extension: Make other fun gross recipes. For a list of 32 fun gross recipes for kids visit:

Application to the Real World: Science can be fun and edible!

Lava Lamps


clear plastic cups
dixie cups
alka seltzer
food color

Concept: When Alka Selzer and water mix it casues a chemical reaction that makes a gas. The gas moves slower through the oil than the water (density) causing the lava lamp effect.

Procedure: Pre pour 1/4 of clear plastic cup with oil. Have students pour Dixie cup of water into oil. Have student observe how the oil and water react to one another (don't mix). Ask student whic one is heavier. The one on top (oil) or the one that sank (water) to the bottom. Add 4-5 drops of food coloring. Observe. Explain that the food coloring is coated in oil. Therefore, it stays suspended in the middle since ild and water don't mix, until is is coated with enough oild to make it heavy enough to sink. Let student drop in an Alk Selzter tablet. Observe from the side of the glass. Watch as the Alka Seltzer forms bubbles of gas that move slowly throug the water.

Extension: Use salt instead of Alka Seltzer. Try different temperatures of water. Use two different colors of food coloring to learn color mixing.

Application to the Real World: A real lava lamp works due to a process called convection. As the wax heats up, it expands, causing less density. This makes it less dense then its surronding liquid causing it to float. When the wax reaches the top of the lamp, away from its heat source, it cools down. This causes the wax to contract and become more dense than its surrounding liquid leading it to sink and the cycle then repeats.

Exploding Film Canisters


empty film canisters (clear containers with insert lids work best)
Alka Seltzer
googles (if available)
toliet paper

Concept: When the Alka Seltzer dissolves in the water it starts to form a gas (carbon dioxide). The gas bubbles keep building up and the pressure from the gas explodes the canister.

Procedure: Fill the film canister 1/2 way with water. Place a piece of toliet paper over canister and push in just enough to keep from getting wet, while forming a nest for the Alka Seltzer. Place the Alka Seltzer in the nest. Place the lid on canister and carefully tear away excess toliet paper. Turn film canister upside down and watch for explosion. Be careful to not lean over canister due to quick reaction time.

Extension: Use other ingredients to make the film canisters explode (lemon juice and baking soda, vinegar and baking soda). Try filling three different canister with three different ingredients. Measure which lid or rocket flies the highest.

Application to Real World: Carbon dioxide is a natural chemical substance (primarily in gas form). It is not toxic, unless in very high quantities. Carbon dioxide is a vital substance to life on Earth. Plant life needs carbon dioxide to function and give off oxygen. Without carbon dioxide, there'd be no plant life! However, carbon dioxide in the Earth's atmoshere is known as a "greenhouse gas." Greenhouse gases absorb heat radiated down by the sun and send the heat back down to the planet to maintain temperatures. The issue is that more carbon dioxide acting as a greenhouse gas in the atmoshere means more heat is trapped and sent back down to a planet unable to absorb or convert it all. This is what global warming is all about.