Category Archives: Grade 12

DNA

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DNA Structure 

  1. Explain the structure of DNA – use the terms nucleotides, antiparallel strands, and complimentary base pairing.

DNA is a nucleic acid polymer.  The structure of it has a unique double helix ladder that forms a twist. The backbone of the DNA is composed of sugar, deoxyribose, and phosphate. Its rungs consist of two bases which are hydrogen-bonded to each other.  Those are adenine to thymine, and guanine to cytosine or simply A, T, C, and G.  The strands of DNA are always opposite on the other side from each other.  They complement each other that way creating one backbone which is opposite to its partnered backbone. 

     

  

  1. How does this activity help model the structure of DNA? What changes could we make to improve the accuracy of this model? Be detailed and constructive.

The activity given to us was a very good demonstration to show how DNA looks. Using the pipe cleaners was very efficient way to bend and form into the shapes we needed.  By the end of each class fingertips hurt because of the wire but, I think it is was the most efficient and simple way to demonstrate the model. 

The beads indicated A, C, G and T and fit the pipe cleaners perfectly, it was a difficult clean up but when the DNA model was finished it looked great.

DNA Replication

  1. When does DNA replication occur?                                                                      DNA replication occurs before cell division. 

2. Name and describe the 3 steps involved in DNA replication. Why does the process occur differently on the “leading” and “lagging” strands

  • Unwinding& unzipping: the two sides of the DNA split and do not bond anymore. The enzyme is the DNA helicase that makes them unwind. 
  • Complimentary base pairing: the back bones are used to make a new complimentary daughter strand. 
  • DNA polymerase:  enzyme that creates the process
  • Joining of adjacent nucleotides: the backbone has to have a continuous strand.

3. The model today wasn’t a great fit for the process we were exploring. What did you do to model the complimentary base pairing and joining of adjacent nucleotides steps of DNA replication. In what ways was this activity well suited to showing this process? In what ways was it inaccurate?

We had to attach white pipe cleaners that represented the nucleotides of half of the parent DNA to form a daughter DNA. The leading strand, had to be attached from the top to the bottom. When we did the lagging we did it from bottom to top. It was inaccurate because the DNA backbone isn’t one long strand of sugar phosphates like the blue pipe cleaner showed, it’s supposed to be the phosphates and sugars bonded together molecule by molecule as each nucleotide is paired. Even though some parts were not realistic, it was accurate because it gave us a good visual to show the same sequence DNA that was split to form same sequence daughter DNA.  Overall, the activity was interesting and really helped to remember the process of DNA replication. 

Protein synthesis: RNA Transcription 

  1. How is mRNA different than DNA?
  • mRNA carries DNA’s message while DNA doesn’t carry any RNA components
  • mRNA has 1 backbone that is short  while DNA has 2 backbones that are long

2. Describe the process of transcription.

  • Unwinding and Unzipping: DNA Helicase breaks the hydrogen bonds between the complimentary base pairs in the chain of nucleotides starting at the very top of the strand.
  • Complimentary Base Pairing: One of the strands is used as a model to create an mRNA strand.  This is where the instructions for building proteins can be found. The other strand cannot be read because the message would not be the same as the mRNA strand concluding a protein cannot be produced from it. The RNA Polymerase joins RNA nucleotides to the DNA strand through hydrogen bonds in order to create a backbone of adjacent nucleotides. 
  • Separating the mRNA from DNA: Once the transcription of the gene is has finished the mRNA separates itself from the DNA forming another double-helix shape.  The mRNA is then edited and leaves the nucleus to spread on the message from the DNA.

 

2. How did today’s activity do a good job of modelling the process of RNA transcription? In what ways was our model inaccurate?

 This model did a good job of demonstrating the process of RNA transcription because we were able to show the mRNA latching onto the DNA and pairing up with the nucleotides.  It was difficult to show how the mRNA only attached onto some parts of the DNA, also we couldn’t show when RNA left the nucleus to pass the message to the DNA. 

Protein Synthesis: Translation 

  1. Describe the process of translation: initiation, elongation, and termination.
  • Initiation: translation starts. mRNA binds to the small ribosomes subunit, then the 2 ribosome subunits bind together.  They begin to read the first codon which is at the “P” site while the second is at the “A” site. 
  • Elongation: ribosomes holds mRNA and allows complimentary tRNA to attach to binding site                                                                                                                                -mRNA has 3 letter code called “codon”

                   -tRNA has complimentary 3 letter code called “anticodon”

                   -each of the 64 possible codons is specific to one of the 20 amino acids

tRNA binds to the “P” site and another tRNA binds to an “A” site. Binding causes changes leading to amino acids letting go of tRNA and binds to neighbouring amino acids.
ribosome moves along mRNA to the 2nd tRNA which is at “P” site and the new tRNA binds to the mRNA codon at the “A” site.

  • Termination: The elongation cycle continues until mRNA reads a stop codon.  This is when the ribosome lets go of the mRNA, tRNA, and the polypeptide chain.

2. How did today’s activity do a good job of modelling the process of translation? In what ways was our model inaccurate?

This model was accurate to show that the ribosome travel along as well as the process of elongation. Moving the pieces were a bit difficult, and taping them took a bit of time but it was worth seeing the change happen in front of our eyes, making it much easier to understand the process. 

Winter Poem

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The Warm Winter

 

Winter slowly creeps into my soul and settles into my skin,

just like a bear cuddled up in his den, hidden during the cold winter season.

What is winter?

It is the covering of the summer’s canvas with white paint

 It is the joy of the bright sunrise on the horizon, magnifying the light on the white.

It is the warmth of a close friend when you are feeling cold.

Blog Log 4 – Love is not the Most Important Aspect in Life

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https://markmanson.net/love

I remember doing a project in the eleventh grade on love. I remember our question being, is love the most important factor in life? In our project my group and I stated that yes love is the most important factor in life whether it be love towards your family, an object or your significant other. This article states otherwise. It’s interesting to read another point of view on love when I think strongly that love is one of the most important factors in life. The article does make sense and I could see as to why the author would say that “love is not enough”. Obviously, love cannot be the only thing that matters in life but it is important. Love is not going to cure all things bad in life, but it is going to help. Love is supposed to make people realize what they’re fighting for and if it’s worth to fight for. Love has the power to change people for the better. If a person loves someone, they have the power to do so many things for each other and it keeps the people motivated. I’m not saying love is the answer to everything, but it does bring out another side to people. Other factors are needed in life than love, but in my opinion, love is one of the most important factors.

Blog log #3 – Trying to hard cancels out happiness

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https://markmanson.net/stop-trying-to-be-happy

After I read this article, I had a bit of an epiphany. I realized that so many people in todays world try so hard to be happy, but can’t because just like the author said happiness “is not something you obtain, but rather something you inhabit.”  I would have to completely agree with what the author says in his article. Happiness is so much more than pleasure from things. To be happy one should feel it at all times, people should feel it naturally rather than to have to buy it. When I say buy happiness, I mean buy objects, vacations and friends to make yourself feel happy. Once you can’t buy it anymore the happiness fades. It can be difficult to actually feel happiness, but it’s a matter of trying new things and living a life that isn’t pressuring. I could vouch for this article, whenever I am upset and force myself to be happy, it’s not real happiness. When I don’t think about happiness just go about a good day, I simply feel it. Many people should read this article, I feel as if people would also have a realization that happiness is not something you force upon yourself, but instead come naturally.

A South African Storm

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“Some believe it is only great power that can hold evil in check, but that is not what I have found. It is the small everyday deeds of ordinary folk that keep the darkness at bay. Small acts of kindness and love.” – Gandalf

” I’m not going to change anything. But I believe it matters in some infinitesimal way that people like the Venda women, and the dozens of people who may walk alongside me on any given day, know that I’m there.” – Alison Howard

People tend to assume that little changes mean almost no change. The thesis in the essay “South African Storm” by Alison Howard and the quote “Some believe it is only great power that can hold evil in check, but that is not what I have found. It is the small everyday deeds of ordinary folk that keep the darkness at bay. Small acts of kindness and love.” from Gandalf, both represent that starting off with little deeds can make a huge impact in the long run. Alison wants to end convectional racism by doing small deeds, she knows that she’s “not going to change anything.”  but she believes “it matters in some infinitesimal way”. She stands up to racism by being a part of their culture, “In black South African culture it is polite to greet every person you pass. That’s what they do, so I do it, too.”; she is doing “small acts of kindness and love”. Alison Howard wants to get rid of racism but she says “I’m not going to change anything” because she knows she can’t be the only one to change it, but she could make a difference by trying.

Happier Single or Taken?

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http://www.alive.com/lifestyle/happy-healthy-single/

This article I read was very amusing. I found it quite humouring reading the authors point of view on being single, because it was the complete opposite of me. It’s interesting reading about other peoples opinions because it opens your mind up a bit and make you more open about other opinions. The author used a few metaphors and similes describing how “wanting to get married was like getting bitten by a bug” he describes it as if he hadn’t been bitten by the bug and always wants to stay single. I have an uncle that lives in Poland that refuses to get married or let alone date, he loves being single and sticks to it. I believe that you have to choose whats right for you and what makes you happy. I know for a fact that I would want to get married when im older, whereas someone else dreads the thought of marriage. People want different things and this article made me realize that each person is different and want different things whether it pleases you or not.

Social Media. Positive or Negative Impact on Teenagers?

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https://childmind.org/article/how-using-social-media-affects-teenagers/

This article links to many kids these days, I could even say I relate to what the author says about teenagers. I’ve always been interested in all sorts of topics about social media because it plays such a big role in peoples lives today. Wherever you go, there are advertisements about it. I liked how the author made the reader connect to what they were writing about. The author uses a few literary devices, but one I noticed the most, was parallelism; The author uses it to make the reader notice what kids do online that affects them negatively. All kids sit on their phones texting, sharing, trolling, scrolling, you name it.”  I always wondered if it affected us in a good or bad way. The author managed to lure me into reading plenty more articles about technology today and how it affects us. I always wished I lived in a time where there was minimal technology, I imagine life to be more simple without it. I noticed that kids these days only care about their phones and the likes they receive per photo they post, instead of focusing on more important topics other than themselves. This article makes me realize how dependant we are on social media that if it were ever taken away, people wouldn’t know what to do with themselves.

What did I learn in the short story Miss Brill about the human condition?

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Throughout the short story Miss Brill, I realized that everyone perceives you differently than you think. Many people tend to judge other around them based on their looks, instead of getting to know the person and their story, how they became who they are. Miss Brill would go out every Sunday and sit on a bench to observe the people around her, it was a bit ironic though because when she was sitting there judging people based on their looks and what they would say when they walked past her, she was being judged unknowingly. Miss Brill didn’t realize she was being judged until one couple made a rude comment about her. People don’t realize how much of an effect it could make on someone if they have been judged, especially if they found out what they were thinking. I know the feeling of being judged for something thats not true. It hurts especially if people don’t know what has happened to them or know the complete story. I learned that if you don’t know a person, before you get any bad thoughts, get to know the person because they could end up being a great friend.