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Run your tongue over your teeth. If it's been a while since you last brushed, you may feel a filmy or fuzzy coating on your teeth. What's there is similar to the slimy coating you might feel if you stuck your finger down into a sink drain or that you might see coating the sides and bottom of a swimming pool that hasn't been kept clean. These are all examples of biofilms.
Biofilms are communities of microbes. They form when bacterial cells able to make large amounts of sticky, slimy substances called polysaccharides (polly-sack-uh-rides) attach themselves to a surface. The slimy coating they make holds the cells to the surface they've settled on and captures other bacteria who live and grow off the waste products produced by the first bacteria. Layers keep being added, creating a complex community.
In this activity, you'll explore whether biofilms can form on all possible surfaces and which they grow best on. You'll also learn something about how we can prevent biofilm formation.
When was the last time you washed your hands? Did you use soap? What have you done since you washed? Have you eaten, put your fingers in your mouth or touched someone else?
Observations in public restrooms have revealed that only about 68 percent of Americans wash up before leaving. Yet thorough hand washing is one of the best ways to prevent the spread of infections. There are millions of microbes on your hands. Most are naturally occurring and harmless. But some may be disease-causing germs. Hand washing with soap lifts off those microbes and rinses them away.
Maybe you’ve heard the term "biodegradable." It basically means something capable of being broken apart into simpler substances by natural biological processes.
But what are these biological processes that break some things down? Why do some things biodegrade more readily than others?
In this experiment, you’ll investigate the biodegrading process of commercial packing peanuts. Print out these pages and follow the directions to do this experiment at home. When you're done, come back to this page to test your newfound knowledge by answering the questions below. (No fair peeking at the answers before you've done the activity!)
As you know, we keep food in refrigerators so it will last longer. But still, sometimes you open a bag of bread or a jar of spaghetti sauce and what do you find? Mold!!
Ever wonder exactly what mold is? And how did it get there? And why sometimes it’s green and other times black or white? Did you know this stuff is alive and growing?
Think about the different places various kinds of plants and animal live. As you know, many, like penguins and cacti, can only live in certain places.
Now think about times you’ve dug a hole in the ground. Did you notice differences in the color of the soil layers? Did you wonder what causes those color differences?
Here's your chance to be an amateur microbiologist.
You don't have to have a scientific degree and wear a white lab coat to do these activities. All you have to do is be willing to muck around with dirt, paint, pondwater and other sometimes gooky stuff.
Most of the activities here use supplies you should be able to find easily in your home or a nearby store.