Symbolic Representation: Circles, Pentagons, and Rectangles
- A nucleotide is represented symbolically as: Circle (phosphate) → Pentagon (sugar) → Rectangle (base).
- This simple model highlights the structure and connectivity of DNA and RNA building blocks.
These shapes don’t represent exact molecular geometry, they're just used to show relationships between components.
How to Interpret and Draw a Nucleotide Diagram
- Start with the Sugar (Pentagon):
- Draw a pentagon in the center to represent the pentose sugar.
- The sugar forms the core connection point for both the phosphate group and the nitrogenous base.
- Add the Phosphate Group (Circle):
- Attach a circle to the sugar’s carbon 5 position (C5’), the upper left corner.
- This circle represents the phosphate group, which allows nucleotides to link together in chains.
- Add the Nitrogenous Base (Rectangle):
- Connect a rectangle to the sugar’s carbon 1 position (C1’), the upper right corner.
- This represents the nitrogenous base, which determines the nucleotide’s identity (A, T, C, G, or U).
- Failing to label the carbons on the pentose sugar.
- This can cause confusion about where the phosphate group (C5) and nitrogenous base (C1) are attached.
- Always label the sugar’s carbons clearly.
- What does the circle represent in a nucleotide diagram?
- What does the pentagon represent?
- What does the rectangle represent?
- Which sugar is found in DNA? Which is found in RNA?
- To which carbon on the sugar is the phosphate group attached?
- To which carbon is the nitrogenous base attached?
