MadSci Network: Botany |
The banana in the bag with a ripe banana will ripen fastest. A paper bag is enough to keep most of the ethylene there. This is because the molecular weight of ethylene is 14 - about the same as the average molecular weight of the molecules in the atmosphere. Since it isn't lighter, it doesn't float up, and since it is not denser, it doesn't sink to the floor. The only thing moving it is disturbances in the air, such as those caused by someone walking past. Since the disturbances don't pass through the bag, most of the ethylene stays put. So, the banana on the shelf will ripen slower, because the ethylene gets blown away from the banana. When a fruit approaches maturity, it begins to produce ethylene gas. This, as you know, causes the fruit to ripen. I don't know the processes that cause it to ripen, but I know it causes it to produce more ethylene. Have you heard the saying "One bad apple spoils the barrel."? If one apple in a barrel ripens, it gives off a lot of ethylene. This makes the other apples ripen faster. As most people have experienced, ripe fruits don't last too long. If they are all green, they last for a long time. Therefore, the banana in the bag with a ripe banana ripens fastest. The unripe banana in the bag will ripen sometime in between. This assumes that all of the unripe bananas are equally ripe to begin with. Some tips: If you do this experiment, and time and money allows, repeat it a few times, recording how you did it each time. You should take all the unripe bananas in one experiment from the same bunch. Different rows of bananas (top to bottom OR left to right) might be SLIGHTLY riper than the others. Take them off the bunch in an organized manner, and record how you did it each time. Maybe even label the bananas. To test which may be riper, you could take an unripe bunch, record how you took them off the bunch, and lablel each banana. Separate them, and put each in a bag by itsself. Then you may see in which order they ripen. There might not be a big difference, in which case it might not matter. If the difference is small, you can do the experiment with any bananas in the bunch. If there is a big difference, you would have to take them off the bunch in a specific pattern. Write down everything, but come up with a simple conclusion, just telling which of the three bananas ripens fastest, and the reason why you think it happened that way. This would be an awesome science fair project or school project. If a fruit is too immature, it never produces ethylene, and doesn't ripen. They might ripen if put in a bag with a ripe fruit. That would be an interesting experiment. Good luck!
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