Hiya Chris, I just got around to listening to your Feb 9 show on my iPod. I have a problem with how you answered the caller who was wondering about how active transport occurs in plant root cells. Initially you misunderstood and discussed xylem and phloem, but even after the caller clarified his question you did not give a correct answer.

Plant cells do indeed set up an electro-chemical potential across their plasma membranes to drive uptake of nutrients against a concentration gradient (similar to animal cells). However, plant cells do NOT posess a sodium-postassium ATPase, which you described in detail while answering the question. In fact, plants use a plasma membrane proton ATPase as the primary pump which generates the elecrto-chemical potential.

Because on that particular show you were going to remove an article of clothing with each wrong answer, it would be appropriate if you posted a picture of yourself without a shirt on in the image gallery here on your website. If one such picture does not appear before the next show, I will be forced to exercise my photoshop skills.

Take it off baby! Show us that sexy pasty science-geek physique!



Sarah Swanson, Postdoc
Penn State Biology Dept.