Monday, May 16, 2011

Race for the Double Helix


Throughout the past two days our biology class watched the movie “The Race for the Double Helix”. It is the story of how James Watson, Francis Crick, Rosalind Franklin and Maurice Wilkens came to discover the double helix in DNA.
After reading the 1953 article of what the scientists came about when they found the double helix, answered a lot of different questions. One of those questions would be the significance of the structure of the double helix. The significance would be that the structure has two helical chains coiled around the same axis. The two chains are related by a dyad perpendicular to the fibre axis. Both of the chains follow to the right of the helix and the phosphates that are on the outside. The structure overall is an open one and the water content was high and the two chains are held together by purine and pyrimidine basis. And they have a certain ration which is 1:1:6:6. This is significant because it was different than anything the scientists even thought of back in the early 1900s. And having Watson and Crick find this was truly an astounding scientific event.
The triple helix didn’t work because DNA actually only has two helix’s. The triple helix would’ve never worked due to the fact that they phosphates were arranged on the outside and the bases on the inside and they were linked together by the hydrogen bonds. And when they took X-rays of it they saw a salt and not a free acid. Without the free acid the structure would not hold together.
The novel feature of the Watson - Crick Model is that the structure had two helical chains each coiled around the same axis. Both of the chains follow right helices and maintain the same sequence. The phosphates are on the outside of the helix and the sugars near the base. And since the phosphates are on the outside the cations have easy access to them. And since the structure is an open one, the water content is high. The main thing, though, is that the two chains are held together by purine and pyrimidine bases.
The sequence of one side of DNA determines the other side because there are two sets of pairs. A – T and C – G. So if one side is ACGT then the other would be TGCA. They can only pair with each other, thus determining the other side’s DNA format.



DISCLAIMER – I found my information from

Friday, May 6, 2011

Watson.

http://ultimatemeaningoflife.com/galeries-crystallography-of-rosalind-franklin/
In an interview with James Watson, 74, he talked about the discovery of the structure of DNA. But it wasn't just him to discover the structure. It was also Francis Crick, Maurice Wilkens and...Rosalind Franklin? Now, I didn't know that she had helped discover the structure of DNA until I read this article. It kind of astonished me. But the real question is, why didn't I know? I mean she helped shape the structure of our future in DNA science and she isn't even acknowledged as one of the people that helped discover it's structure.


Now, listen here folks. This poor lady got jipped on a Nobel Prize that the other 3 guys got. Now, I don't think that is fair. If it wasn't for her they wouldn't of even discovered the double helix in the first place! I understand why people are making the claims that she was left out of the spot light, because she was! It is a horrible thing and the poor lady just did not get any credit.


I don't think that she got the credit that she deserves at all, why? Because when we think of the discovery of the double helix we don't think of Mrs. Franklin. And I think we should due to the fact she had greatly contributed it to, again, we wouldn't even know about it if it weren't for her.

 Yes this controversy has arose elsewhere. It happens everyday. One current example is Facebook. The two Winklevoss twins that had helped Mark Zuckerberg form the website but in turn didn't get any credit for helping him. It's just one example of many.

Scientists can prevent this type of controversy in the future by telling everyone who was involved and what they did. It's the only fair way to get the word out and to help everyone get the recognition that they should.














Now this is why she is called the Dark Lady of DNA. ;)

Tuesday, April 19, 2011

GATTACA


Have you ever seen the movie GATTACA? I actually had never even heard of it up until my bio teacher brought it up. Personally when she was describing it I thought it would be a nerdy sci-fi type of movie, which is a genre that I am not really into. BUT - To my surprise, when we watched the movie, it turned out to be really good! The story had a great plot and a wonderful theme. So, shout out to Mrs. S, for opening my eyes to such a wonderful movie! :)

But anyway, onto the questions about the movie. Here goes...


1. What are the advantages and disadvantages to having a society like that portrayed in GATTACA?
 
Three advantages of the GATTACA world are that you have the chance to give your child the best chance of living, and the best chance of leading a successful life. Another is that since the people have good genes they can operate things more successfully in their jobs. Lastly in the GATTACA world they can live a long time, and be healthy throughout that long life. Three disadvantages are that since there is a chance to have a “perfect” employee no one hires an invalid, even though they could still to as much hard work needed. Another negative aspect is that there are no surprises in life, you know when you are going to die and you know from what. You know if you are going to get a disease and what that disease might be. And lastly would be that there wouldn’t be much personality in the community of people. If they all were “perfect” then nothing would be interesting.


2.If you were able to exclude the eccentric, the different, the misfits, and the weak, what would happen to society?

To be honest, I think society would turn out to be much more boring than it is right now. I personally believe that the different, the misfits, and the eccentric make our world worth living. They are different because we have that choice to be. I would much rather be different than the same as everyone else. (I probably am a little eccentric now anyway. ;) I think that society would eventually collapse because they would have no one to look up to since they all are the same, and I think that life would be so much more less interesting if we only had "valids" in society.

3. What limits should be placed on genetic engineering? Should it be allowed at all? Should it be limited to the elimination of disease and physical imperfections? Why or why not?

I don't think that genetic engineering should be completely banished. I think it is a wonderful thing that we can now make cure someone from a disease before they even deal with it. I do think that it should have some restrictions though, why? Because if we didn't the world would have so many "perfect" people that we would have nothing to strive for. I think that it should only be allowed to cure serious diseases, because I know that no one would want their child to go through that. But that is the only thing that I think genetic engineering should be used for. I think it is kind of shallow to pick out your child's physical appearance, I think that a parent should be happy no matter what their child does look like. I also don't think that they should make any changes effecting the mental capability of the child. I believe that you still need to try hard to get where you are. I don't think that it  should just be given to you.

All in all I think that this was a great movie choice, and it really brought to attention what the negative aspects of genetic engineering are. We are actually coming really close to being able to change genetics like they did in GATTACA. So, I think that this movie is great to see how horrible (or wonderful) the genetic engineering can be.

Friday, March 4, 2011

Bacteria + High School Students = Gross.

Just yesterday in Bio class we did a disinfectant and antiseptic lab to see how it effected the bacteria on  normal everyday things that we touch and use. We all have heard of what disinfectants and antiseptics but to we really know what they are and what they are used for? This post is primarily based on what I did during the lab and what I found out about the bacteria lurking in our school.

First, let me explain what disinfectants and antiseptics are for those of you who don't know.
Both of these substances are agents that kill, or at least control the growth of bacteria.  Antiseptics are used on living tissue while disinfectants are used on non-living things such as floors, counter tops, dishes, stall doors, etc. Of course the disinfectant bleach worked the best because it has harsher chemicals, which is also the reason why we don't use it on living things because it would probably eat our skin or something.

On to the lab...
We started this lab off with some agar in a petri dish. We had to first swab our index finger with a clean cotton swab and we put that onto it's section on the agar. We did the same thing to the second and third section except we used alcohol on one and soap on the other. After we had swabbed some bacteria off or our skin we got to choose what we wanted our surface to be. I chose...drum roll please...the nasty stall door in the girls bathroom. I figured that after we girls get done with our business we have to open the door all before we wash our hands or anything. So I was curious as to see how much bacteria there actually was. I swabbed that with just a clean cotton swab, one drenched in alcohol, and one drenched in bleach. 

After we had done  with that we put our petri dish into an incubator for two days to let the bacteria grow. And what a delight it was to find out how dirty the stall door actually was.
It ended up being that my skin really wasn't that 'dirty', which could be because I am a cleanly person or our hands really just don't get very dirty. But I did have more bacteria on my hand when I didn't use the alcohol and soap. I had NOTHING on the finger I used alcohol in. I guess our doctors are pretty smart using that to clean our skin before shots. But the finger that I washed with antibacterial soap still had some bacterial growth, which kind of bothered me. But it's not like I will from now on wash my hands with alcohol. The soap did a pretty good job, I guess.

As for the stall door, there was A LOT of growth. It practically covered all of the section it was in. Not good. But what do we expect? People don't have a chance to wash their hands RIGHT after we go to the bathroom. Thank goodness we have sinks. The part of the door that I treated with alcohol had less bacteria, but still quite a bit and the part of the door that I swabbed with bleach only had one growth. Bleach is kind of awesome.



And I just thought I should insert this into my post. I later put the bacteria of the normal stall under a microscope and found that it was bacillus. Very interesting...

Friday, February 18, 2011

I've Got a Lava Lamp, Nananana.


video
     
     Just yesterday my biology class did a very interesting experimnent. We all made our own little lava lamp. The lava lamp was invented by Edward Craven Walker in 1963. A lava lamp is  defined as a display device with the creation of colored globs of oozing wax suspended in water (mixed with a cocktail of “secret ingredients”) and encased in an illuminated glass tube. Edward Craven Walker got the idea for this creation after walking into a pub. He spent the next 15 years perfecting the invention so that it could be mass-produced. The Astro Lamp, later called the Lava Lamp, was launched in 1963. This all happened just in time for the Hippie/Disco age of the Lava Lamp.
   
       In the lab we filled a water bottle 3/4ths of the way up with vegetable oil and we filled the rest of it with the ol' H2O. After that we put in some color with some food coloring to make it look more psychedelic. Then we added the Alka Seltzer tablets (You could of used salt too, but Erika and I decided to go with the tablets.) After we added a couple of those our lava lamp came to life! It started bubbling and looking just like a cheap lava lamp you by at a yard sale. It was AWESOME.
    
     The person that was across from us at the table, Chelsea, used the salt and it seemed like the salt didn't have as much affect on the lava lamp. That could be because she had to stir hers and it mixed up everything for a bit, but then again it could be because it didn't have the same chemical composition as the Alka Seltzer. All in all it was a successful experiment, and it was definitely enjoyable.
   
 
I answered the discussion questions in the video already, but I will go through them again through text.

video

Why does the oil "float" on water and not vice versa?
For an easy answer - The oil floats because it is less dense then the water. In other words it weighs less. For a more in depth answer -  Pure waters density is 1000kg/m³. Oil is usually around the 800kg/m³. Therefore the lighter less dense fluid floats to the top. Just like how a balloon filled with helium floats, the helium is less dense than the air.

Why doesn't the oil and water mix?
The oil and water doesn't mix because because oil is hydrophobic. If you don't know what that means look at the prefix and suffix. Hydro - Water, Phobic - Fear. Pretty much the oil is afraid of the water and doesn't mix. This is based on the oxygen molecules and how they interact with each other.

Why do you thin the food coloring didn't adhere to the oil?
I think that it didn't adhere to the oil because, well...the food coloring is hydrophilic (Water loving) and it mixed with the water instead. (Yessssss, I know this one was short, please forgive me. ;)

Discuss the creation of the "lava". What do you think is happening?
I think that the "lava" is created because the Alka Seltzer tablets react and oxidize the water making the food-colored water float through the oil making it look like a lava lamp.

Tuesday, February 8, 2011

Quorum Sensing, Bonnie Bassler, and Glowing Cats.

http://www.pbs.org/wgbh/nova/body/bassler-bacteria.html
     Bonnie Bassler, a graduate from Princeton University, is now a leading scientist in the discovery of bacteria, and the revolution of bacteria as well. Bassler was interviewed by NOVA about her recent research on a form of bacteria that has a blue glow to it. The bacteria is called Vibrio harveyi. She also talked about the astonishing science of quarom sensing, which is essentially what allows bacteria to be multi-cellular.


    In the article, Bassler talked about many things involving bacteria. Such as how much is actually around us and how most of the bacteria isn't even harmful. How there are ten times more bacteria in our bodies, than the cells that are in our bodies. She stated that "They protect us. And you can't even digest your food without the bacteria that are in your gut. They have enzymes and proteins that allow you to metabolize foods you eat.", essentially meaning that we need bacteria to function. And sure there are some that are bad, but there are also so many good forms. Our bodies are swarming with bacteria, and we don't even have the slightest idea what it would be like without it. We are stuck with bacteria, so we better get used to having it stick around.

http://www.pbs.org/wgbh/nova/body/
bassler-bacteria.html

       Also in the article there was talk about quarum sensing, which in other words, is how bacterium actually communicates with each other. Yes, bacteria doesn't seem like they would communicate with each other, i mean they don't even have a nucleus! But they send out chemicals, and that is how the bacteria ultimately communicates with each other. While bacteria is growing, each different cell releases a small amount of chemicals, auto-inducers. And with those more and more molecules begin to grow.

http://www.pbs.org/wgbh/nova
/body/bassler-bacteria.html

      The bacterium that started this whole thing was the glowing blue bacteria that I had previously said in this post, Vibrio harveyi. This is the bacteria that they look at to see how Quarom sensing actually works...
      I know what you are thinking, get back to the glowing bacteria. Well, it seems like it should be a rare thing, but actually in the ocean it is the norm to have a glow to anything, so they can naturally see. I was watching something on the Internet a few months ago, and actually they had animals (cats, rats, birds) eat food with some kind of bacterium like this one and the animals grew up to glow as well. It just goes to show you how astonishing this all is.

     But back to the Quarom Sensing, this bacteria is controlled by Quarom Sensing, which is why they glow. They send out the chemicals and in turn it brings a blue luminescence to the bacteria. This is also providing research for future bacteria and how Quarom Sensing will be intertwined with that as well.
     I personally think that this is an amazing thing to have, I can think of so many ways we could potentially use Quarom Sensing in our daily lives, and how actually we are already using it with out even knowing. It's a great thing to have scientists like Bonnie Bassler and her crew to figure out new things, and potentially change the world.


R. Gent

Thursday, December 2, 2010

Kwashiorkor!

http://main.nc.us/openstudio/tinamanley/Iraq/kwash.htm
1.       Kwashiorkor is  an acute form of childhood protein-energy malnutrition. It is severe malnutrition when children have a diet that is high in carbohydrates and low in protein. It usually affects children in impoverished countries because of the lack of recourses that they have; occasionally it effects the elderly as well. It is predominately found in impoverished countries that have been affected by drought, and countries that had political unrest.
2.       Protien is useful because it is one of the main classes of food that provide energy to our body. So, if we don’t have very much protein that enters our body, we are lacking on the energy that it provides.  And due to the lacking of energy, it could stunt growth, and lower resistance to disease. Without the protein that our body needs it could potentially lead to a disease called kwashiorkor.
3.       In popular low carb diets, like Atkins, we think that that we are going to lose weight and get healthier by cutting out most of the carbohydrates in our body. But that is not the case. In these low-carb high-protein diets they could cause you more harm than good. In recent studies it shows that these diets could contribute to cancer and heart disease. To healthily diet is to eat good sources of protein like tofu and almonds. Also eat good fats like olive oil and avocados.  Also make sure to look at the nutritional labels to know you are getting good protein. The main t thing is to moderate your diet.
Due to low carb diets such as the Atkins diet you are depleting your body from glycogen resulting in harm to your muscles and liver. It could cause you to get tired more often and just lose overall energy that you need to sustain a healthy life.  You lose muscle, and your skin will get saggy. Getting rid of your carbohydrates also results in a rise in insulin. Lack of carbs also could affect your mind as well. Overall we see that these diets are not good for you and you need to maintain your protein and carbohydrates so you can stay healthy and live an abundant life.
4.       In low carb, high protein diets there are many dangers. By adding more protein to a diet would cause severe stress to your body. Also, it would cause a buildup in ketones. Ketogenic diets can thrust your kidneys into overdrive in order to flush these ketones from your body. And while your body is getting rid of the ketones, it is also getting rid of a lot of water which could potentially put you at risk for dehydration. And due to the dehydration, it strains your kidneys. And you could end up feeling sick, and dizzy. So if you are planning on dieting, stay away from this diet. It could cause you more harm than good.

R. Gent