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Malabar spinach can be used for this experiment. We recommend using green shades and leaves that are not too waxy on the surface as the waxy cuticle can make it difficult to extract the gasses from the leaf disks.

5

We recommend about 20 leaf disks per trial.

@@LabXchange oh our teacher told 5

While you could use red portions of the leaves to cut the leaf discs, it is not recommended as the chlorophyll composition may differ from the green parts of the leaf and therefore, this would introduce another extraneous variable into the experiment.

The structure of the large veins makes it much more challenging to extract gasses via the vacuum mechanism rather than the flatter parts of the leaf. As the plant photosynthesizes, the gas oxygen will be produced within the leaves which will cause the leaf disks to float. Therefore, we are able to visually measure photosynthesis as the amount of floating leaf disks per minute. If we did not extract the gases from the leaves through the use of a vacuum, we would not be able to track oxygen production as a measure of photosynthesis.

But why is it harder extract gasses in areas with large veins?

@@alexisyu8946 Large veins are structured to tunnel gasses and nutrients throughout the leaf and therefore are not as flat as the rest of the leaf. The structure of the large veins makes it much more challenging to extract gasses via the vacuum mechanism rather than the flatter parts of the leaf. Thus, leaf disks cut from veins will typically float. Remember that to visually measure photosynthesis we need to first sink the leaf disks by extracting gasses via the vacuum method and then use the amount of floating leaf disks per minute as a measure of photosynthesis.

So glad to hear it!

A vacuum is necessary to extract the gases from the leaves. As the plant photosynthesizes, the gas oxygen will be produced within the leaves which will cause the leaf disks to float. Therefore, we are able to visually measure photosynthesis as the amount of floating leaf disks per minute. If we did not extract the gases from the leaves through the use of a vacuum, we would not be able to track oxygen production as a measure of photosynthesis.

@LabXchange thankyou.

Yes, of course! Please note that our interface has changed, so please check our Help Center for the latest information about creating a class.

Yes, a leaf disk assay can be used to measure the effect temperature has on rate of photosynthesis!

Feel better soon! Glad you enjoyed the video.

If the vacuum doesn't work the first time, you can try again with the same leaves. However, after a few tries, the leaves would likely be damaged and we recommend starting with new disks. Adding soap is also an important step for breaking through the waxy cuticle of the plant in order to extract the oxygen.

Hi! This is a great question. The only reason the sodium potassium pump is not an antiporter is because transporters are a form of Passive Transport. Which means the do NOT use energy because they move down the concentration gradient, but the sodium potassium pump DOES use energy. It uses ATP so it is an active transport which makes it a primary active transport. I hope this helps and hope you do well on your test!

@@jaq6297 wait a minute, in this video she says antiporters use energy? How can it still be passive then?

@mustafakemal7320 Hi! Thank you for your question. You're right, I was unclear. I meant ATP energy which I only mentioned at the end of my comment, but when I referred to energy, I meant to say ATP energy. The sodium potassium pump goes against their concentration gradient, so they use up ATP energy since it requires more effort. I hope now it's more clear