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?

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.

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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!

When a stop codon is encountered, the ribosome releases the finished polypeptide and its two subunits separate. These subunits can then be used to start the synthesis of another polypeptide on another mRNA molecule.

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