Welcome Guest Search | Active Topics |

Tag as favorite
Gene Chip
#1 Posted : Wednesday, June 24, 2020 5:25:18 AM
Rank: Advanced Member

Groups: Registered
Joined: 6/8/2020
Posts: 62

Thanks: 0 times
Was thanked: 0 time(s) in 0 post(s)

For question 94 on page 122 in EK Biology 1, why wouldn't the answer be yellow? Since you are combining beta cells from after a fast, when insulin would be downregualted, and beta cells from after eating, when insulin would be upregulated, wouldn't the overall detection of insulin be in the middle (yellow)?

Thank you
#2 Posted : Thursday, June 25, 2020 9:33:25 PM
Rank: Advanced Member

Groups: Registered
Joined: 6/24/2019
Posts: 250

Thanks: 0 times
Was thanked: 0 time(s) in 0 post(s)
Hey, this is definitely a tough question.

I would say that a good ideal would be to narrow this down to A and B (green and yellow), and getting yellow is not an unreasonable thing (I would say most people, myself included, would answer this on reflex).

In terms of why green:

For this array, it is true that we would get a variety of dots on our array, some green, some yellow and some red as there are multiple types of cell samples.

The key here is that they ask for the colour of the region of the chip containing probes for the insulin gene, which is upregulated in the second sample.

This region of the dot has the highest affinity to bind to green labelled insulin RNA, so if there is a lot of green labelled insulin in the sample, it will out compete any red mRNA, which will wash off that part of the chip, leaving the dot completely green. That is, although you have a mix of red and green, the binding affinity and amount of green mRNA is what will affect the colour of the dot.

Therefore, we see a gene chip more like default red, and as there is more mRNA of your gene, the red will get outcompeted. For example if insulin was not upregulated by eating, there might only be enough insulin to kick off 50% of the red mRNA, and you would wind up with yellow.

Please let me know if this is unclear, it's a bit of a more subtle argument.
Users browsing this topic
Tag as favorite
You cannot post new topics in this forum.
You cannot reply to topics in this forum.
You cannot delete your posts in this forum.
You cannot edit your posts in this forum.
You cannot create polls in this forum.
You cannot vote in polls in this forum.

Clean Slate theme by Jaben Cargman (Tiny Gecko)
Powered by YAF | YAF © 2003-2009, Yet Another Forum.NET
This page was generated in 0.092 seconds.