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Conceptual Lens of "models"
Conceptual Lens of "models"
Models are useful to simulate reality.
help to visualise to aid understanding
can be used to make predictions
Limitations of models:
simplification of reality; missing details
differences between models and reality
In this lesson, students built a physical model of DNA using candy. The goal of model building is to allow students to visualise the structure of DNA more easily; and hopefully will appeal to the kinaesthetic learners.
The subunit of DNA is called the nucleotide.
The subunit of DNA is called the nucleotide.
Each nucleotide consists of a phosphate group (gummy bear), deoxyribose sugar (marshmellow) and a nitrogenous base (gummy bear)
There are four kinds of nucleotides.
There are four kinds of nucleotides.
This is because there are four different kinds of nitrogenous bases. They are A (adenine), T (thymine), G (guanine) and C (cytosine).
Each differently coloured gummy bear represents a different nitrogenous base.
Nucleotides polymerise to form a polynucleotide.
The covalent bonds formed between the sugar and phosphate groups during polymerisation is known as the phosphodiester bond.
A DNA molecule consists of two polynucleotide strands wrapped around each other in a double helix.
The opposite polynucleotide strand formed is anti-parallel in orientation. The bases found on the opposite strand are complementary to the original strand.
The rules of base pairing are: A pairs with T, & C pairs with G
The following photos were kindly taken by my colleague who visited my classroom when I conducted an open classroom for DNA model making for my Sec 3 IP students.
If your thirst for knowledge on the structure of DNA is still not satisfied, head over to my Bedazzling Biology Factoid page under the topic of Molecular Genetics, where you can learn more about the history of the discovery of DNA.
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