Data

Protein Tests

Question: Will the liquid in my Nepenthes digest insects?

Prediction: Plant extracts will contain enzymes that digest insect proteins (proteases).

Materials: buffer, freeze dried fly extract, nepenthes sanguinea liquid, Trypsin, Dispace

The experiment: We created five sample tubes, one filled with just insect extract (#1) , one filled with just plant extract (#2), one with insect and plant extract (#3, the experimental tube), one filled with insects and trypsin: an enzyme we already knew would digest proteins (#4, control protease). Another control sample: Dispace and insect extract, and one neutral sample with just buffer.

After centrifuging (mixing with a special machine) each sample tube, we incubated at 37˚ C (to simulate a tropical temperature, since the Nepenthes is a tropical plant) for one hour. Then we seperated the proteins by using electrophesis. Electrophesis coats each individual protein with a negative charge. So, when we put the proteins on the top of the gel, and an electric field, with the positive charge at the bottom, the proteins migrated towards the bottom (because negatives and positives attract). The gel acted as a molecular sieve, so the smaller proteins go through faster, and when the proteins are stained, each size of protein appears as a bar (see picture below). So, we could compare the bars made by the insects alone, and the bars made by the Nepenthes extract, and see where certain bands were digested.

Liquids added	#1	#2	#3	#4	#5
Buffer	None	500ml	none	none	1000 ml
insect extract	1000 ml	none	500ml	500ml	none
Nepenthes Extract	None	500	500 ml	none	none
Trypsin (protease control)	None	none	none	500ml	none
Dispace (protease control)	none	none	none	none	none

The Results

This is a picture of the bands created by the proteins.

These proteins where incubated for one hour.

Lane 1- insect extract

Lane 2- plant extract

Lane 3- insect extract + plant extract

Lane 4- insect extract and Trypsin

Lane 5- Dispace and insect extract

Lane 6- Buffer only (control Lane)

What We observed: -there are five protein bands in the insects only lane (#1)

-there is one strip in the buffer lane (6) we know to ignore this strip, it is contamination (probably dead skin)

-the first and third bands have been digested in lane 4 and 3 (that is: the control enzymes)

-notice that the third band (boxed in red) was particularly digested by the plant extract. (lane 3)

In conclusion, I have found that the enzymes are capable of digestion. In the future, I will try without a neutral Ph buffer, because the enzymes are Ph 1 (very acidic) therefore they might rely more on digesting with the acids.

The fruit fly experiment

Question: which plant is the most attractive and efficient?

Hypothesis: The butterwort will attract the most insects because it produces potent dew, and is very sticky.

                  Materials

-Transparent glass bowls
- Pinguicula Moranesis
- Drosera Capensis
- Nepenthes
- Dionaea
- Wingless fruit flies
                    Drosera Simulation
                         Styrofoam ball (base)
                         Toothpicks (stems)
                         Felt tack floor protectors (sticky head)
                    Butterwort
                         Styrofoam ball (base)
                         Velcro, sticky side (leaves)
                         Toothpick (flower stem)
                         Colored paper (flower)

Method

For this experiment, we took four carnivorous plants: a sundew, a Venus flytrap, a tropical pitcher, and a butterwort. We also used a simulation of a sundew and a butterwort. Each plant and plant model was placed in a transparent glass bowl covered in Saran Wrap. We released five to ten wingless fruit flies into each bowl. After that we observed the plants to see how many insects they could catch over a time period of five minutes.

Results

Plant Fruit Flies caught

Drosera C. 4

Dionaea 0

Pinguicula 1

Nepenthes 4

2

Fake Drosera

Fake Piguicula 0 (many attracted)

We left the flies in the bowls and observed them a few days later.
After spending six days in the humidity of the covered bowls, the plants were more active and the flypaper traps (sundew and butterwort) had more dew. It also allowed flies to hatch more frequently.

Conclusion

During this test, we found that the flies were most attracted to the Drosera and the Pinguicula. However, the sundew had the best trapping mechanisms. The pitcher plant caught four flies, but didn't attract that many. Our fake sundew caught two flies, and the fake butterwort attracted many, but didn't catch any, because it wasn't sticky enough. The Venus flytrap was unsuccessful in trapping any flies, probably due to the fact that they were too small too trigger the
hairs.

In conclusion, it seems that the plants that are the dewiest are the most attractive. The fruit flies went strait to the sundew, and it caught the most flies.