Something Smelly in STEM (for Parents/Teachers)

Setup

• Find a partner that you can work well with. You will be sharing and helping each other out all day. This lab requires teamwork and focus so make sure whoever you are working with is good at both.

• Go to one of the 8 lab tables and sit across the table from one another

a.      Note: There is to be a maximum of 6 kids at each lab table

• Listen to the lecture on Olfaction and take notes!

Lab Section One: The nose knows

1. Create a grid in your notebook that looks something like this, make sure you leave enough space for your partner to write in the second column for you.

2. Between you and your partner, pick who will be blind folded first. No matter who goes first you both will get a turn to try this.
3. Have whoever is not being blind folded first take their partners lab notebook so they can write down the responses for whoever is being blindfolded first.
4. Whoever is being blindfolded, put on the blindfold and make sure you cannot see. This activity is meant to remove your senses of sight, taste, hearing and touch. It should help you focus on just smelling what your partner wafts in front of your nose.
5. Now the partner that is not blindfolded, grab from samples 1-8 at random. Once you have a sample open the lid and gently waft (move side to side) the sample under your blindfolded partners nose.
6. Write down what they think the smell is on the line that matches the number written on the lid.
7. Make sure to put the lid back on securely and set the container back in the basket. You will be
8. Repeat steps 5-8 until the blindfolded partner has smelled each one and the non-blindfolded partner has written down all their responses.
9. Now switch roles and repeat steps 3-8
10. When you are all done with repeating those steps, examine each container again without a blindfold and write down what you think each thing is in column 3
11. The answers to the very end of this section of the lab are with your teacher, once you finish this section ask your teacher to provide you with the answers to what each smell was.

Section Two: Taste verses Smell

1. Continue working with your partner for this section as well
2. For this section you will be looking at, dissecting, smelling and tasting a few different items contained in containers 9-12
3. You may work through these materials in any order you like. Start by creating a table in your lab notebook that looks like this:

4. Start by pulling one of the sample containers labeled 9, 10, 11, or 12.
5. Remove one piece of material from the sample container and place on your lab mat
6. Smell the sample, then begin your dissection
7. Using your butter knife gently remove the outer layer from the material you are studying and set it aside
8. If you see any seeds separate them from the flesh as well
9. Now you should have two to three parts of your sample. Smell each part separately and record what you smell
10. Next cut the flesh into at least two pieces (be careful some of the materials might make you cry) and taste the flesh
11. Record what it tastes like
12. Does it taste the same as it smells? Record you answer
    

Section Three: Difference in Smell

1. Continue working with your partner for this section as well
2. The samples that you will be working with will be with your teacher at the front of the class. To move onto this section, you will need to complete the previous two sections and bring up your results for your teacher to look at.
3. Your teacher will provide you with two oranges and a piece of scented wax
4. Gently peel your orange and set aside the fruit (you may eat it after you have cleaned up your lab space and are ready to go home for the day)
5. Examine the orange peel, smell the inside white part and the outside orange part
6. Do they smell the same?
7. Gently rub your fingers on the inside white part
8. Do you fingers now smell like orange?
9. Wipe your fingers off
10. Do they still smell like orange?
11. Gently rub your fingers on the outside orange part
12. Do your fingers smell like orange?
13. Wipe your fingers off
14. Do they still smell like orange?
• Note: your fingers should smell more strongly of orange from the outside of the orange, can you figure out why?
15. Now examine the scented wax
16. Gently rub your fingers on the scented wax
17. Do your fingers smell like the scented wax?
18. Wipe your fingers off
19. Do they still smell like scented wax?
• Note: your fingers should smell strongly of scented wax, can you figure out why?
20. What does the wax have in common with the orange peel?

Section One: Sample Information

• Strawberry – fresh, ripe strawberries. The stems have been cut off and provide very little scent to the strawberry smell, you should simply smell strawberries, but if you did not smell strawberries realize the smell can dimish the longer it has been cut or the container has been open
• Orange Extract on cotton ball – the orange extract may smell like lime or lemon, most of the smell from an orange comes from the oil in the skin of citrus fruits, the citrus fruits have many odorants that create similar smells
• Banana – This banana is in its peel. The peel provides its own scent to the banana and adjusts the smell slightly from the banana extract
• Mandarin Oranges – will smell very similar to the orange extract, but since they are out of the peel and have the white membrane around the kernels of flesh in the middle it may be very difficult to make out that scent. One thing to take from this is that a lot of smell comes from the peel of citrus fruit, when that is removed it becomes harder to identify the smell.
• Maple Extract on cotton ball – should smell very similar to real maple syrup but if you do not know the smell of maple syrup you would just smell a woody sweet smell
• Strawberry Extract on cotton ball – strawberry extract will smell different from fresh strawberries because it contains other fruit juices in order to maintain a strawberry flavor through the cooking process
• Maple Syrup – can have quite a woody smell, which makes a lot of sense since it is made from the sap from a tree. If you smelled wood or branches you would not be far off and should be
• Banana Extract on cotton ball – should smell very similar to the fresh banana, but may smell more like banana bread because the peel of a banana provides its own scent that changes what you smell verses the banana extract which comes from the banana flesh without the peel.

Section Two: Sample Information

• Bac Ha – very little taste or smell, but high in acid. Indian taro, is a 1.5–3 m tall herb with a large, fibrous, inedible corm, producing at its apex a whorl of large leaves. The leaf stalk is used as a vegetable in some areas in South East Asia and Japan. You were given the leaf stalk to dissect
• Onion – very stinky smell, but sweetish taste. The onion, also known as the bulb onion or common onion, is a vegetable that is the most widely cultivated species of the genus Allium. Its close relatives include the garlic, leek, chive, and Chinese onion. The synthase enzyme (exposed when cutting through the membranes of the onion) converts the amino acids sulfoxides of the onion into sulfenic acid. The unstable sulfenic acid rearranges itself into syn-ropanethial-S-oxide. Syn-propanethial-S-oxide gets into the air and comes in contact with our eyes. The lachrymal glands become irritated and produces the tears! 
• Extra sharp white cheddar – strong aroma, strong flavor. The cheddar-making process starts out like most other cheeses: milk is cultured, meaning starter bacteria is added to acidify the milk. When enough acid is developed, rennet is added and milk forms curds. After the curds form, the watery whey is drained out to leave behind more concentrated curds, then heated to about 100 degrees F to release even more whey and start to melt together. The curds are formed into big slabs that are piled together and flipped over many times, getting denser and releasing more whey. Finally, the pressed curds are passed through a mill to make small curds again before being pressed into molds to drain further and age.
• Burdock Root – Earthy smell, earthy taste. Arctium lappa, commonly called greater burdock, gobō, edible burdock, lappa, beggar's buttons, thorny burr, or happy major is a Eurasian species of plants in the sunflower family, cultivated in gardens for its root used as a vegetable.

Section Three: Sample Information

The wax and the orange peel both have oils contained inside them. Oils evaporate but far more slowly than water based odorants. This means that the smell from both will remain on your skin for longer than with the water based odorants found in the fruit or the inside white part of the skin.