Did you know that we share 50% of our DNA with a banana? Bananas don’t have DNA that codes for eye colour and we probably don’t any genes that produce yellow peels. What we share is similar basic biochemistry, such things as DNA replication, cell metabolism, and regulation of cell growth, to name a few. One thing that you can do with banana DNA is easily extract it. We all know that cells are too small to see and that DNA is even smaller, BUT if you mash a whole a banana, you can produce enough DNA to make a small clump. That was one of the activities at Science Rendezvous this past Saturday.
Science Rendezvous is science outreach festival that occurs across Canada, a day when science hits the streets. This year it was May 7th. In Toronto, there were information booths, demonstrations, and activities by students from Ryerson (at Yonge Dundas Square) and students from U of T (St. George Street).
“There’s no place like GenHome” is a project by Ryerson students to break a Guinness World Record by building the longest DNA model. DNA, or deoxyribonucleic acid, is a double helix. Although it is a complex molecule, it can be broken down into components called nucleotides. Nucleotides consist three parts – deoxyribose which is a sugar molecule, phosphate, and an organic base. At the risk of being too simplistic (because the chemistry of DNA is way beyond the scope of this blog), the sugar and phosphate of the nucleotides form the backbone of the double helices. The organic bases are in the space between the two backbones and if they are ordered properly, the bases hold the double helix together.
A couple more things you need to know about DNA. First, there are four bases, adenine (A), thymine (T), cytosine (C), and guanine (G). And second, bases come in pairs and only certain pairs can exist if the double helix is to form properly. Adenine has to pair with thymine and cytosine has to pair with guanine, i.e. A with T and C with G and nothing else.
How would you build a DNA model? The Ryerson University students wanted to get people involved in the project and if you were at Science Rendezvous, you could have become part of their DNA model.
below: Bases need partners and so do you ! Find a partner and take a spin.
Are the two of you A & T or G & C?
below: Next, have your picture taken with your base letter.
A few moments later your picture is printed and ready to attach to the DNA model.
below: My partner for the activity adds his G (toe to toe with my C).
I don’t know how long the DNA model is at this point. I was hoping that there would be some information online but nothing has shown up yet.
Also, If you want to try extracting the DNA from a banana, the instructions are online at numerous sites including Scientific American. You will need a banana, water, salt, detergent, rubbing alcohol, and a coffee filter. Have fun!
*** a little breather after all that molecular biology ***
below: At Science Rendezvous they were walking together until she saw my camera and then she tried to get away. Hmmm…. Mr. Scientist Creature (mutant science rodent?!), maybe she was embarrassed? 🙂
as I walk Toronto 