Problem Description:
The task is to arrange the given shapes to form a model of a DNA molecule. The provided shapes represent different components of DNA, and the goal is to correctly assemble them into a double helix structure.
Components Provided:
1.
Deoxyribose (Turquoise pentagons)
2.
Adenine (Green rectangles)
3.
Thymine (Red rectangles)
4.
Phosphate (Pink circles)
5.
Guanine (Orange rectangles)
6.
Cytosine (Yellow rectangles)
7.
Hydrogen bonds (Black lines)
Solution Approach:
To solve this problem, we need to understand the basic structure of DNA:
1.
DNA Structure: DNA is a double helix composed of two complementary strands held together by hydrogen bonds.
2.
Components:
-
Backbone: Composed of alternating phosphate groups and deoxyribose sugars.
-
Bases: Four types of nitrogenous bases—Adenine (A), Thymine (T), Guanine (G), and Cytosine (C). They pair specifically: A pairs with T, and G pairs with C.
-
Hydrogen Bonds: Connect the complementary base pairs.
Step-by-Step Solution:
#### 1.
Form the Backbone:
- Each strand of DNA has a backbone made up of alternating phosphate groups and deoxyribose sugars.
- Arrange the
pink circles (phosphates) and
turquoise pentagons (deoxyribose) in an alternating pattern to form the backbone of each strand.
#### 2.
Attach Bases to the Deoxyribose:
- Each deoxyribose sugar in the backbone attaches to one of the four nitrogenous bases.
- Place the
green rectangles (Adenine),
red rectangles (Thymine),
orange rectangles (Guanine), and
yellow rectangles (Cytosine) on top of the deoxyribose sugars.
#### 3.
Pair the Bases:
- Adenine (A) pairs with Thymine (T) using
two hydrogen bonds.
- Guanine (G) pairs with Cytosine (C) using
three hydrogen bonds.
- Use the
black lines (hydrogen bonds) to connect the complementary base pairs across the two strands.
#### 4.
Arrange the Strands:
- The two strands should run in opposite directions (antiparallel).
- Ensure that the bases are correctly paired and connected by hydrogen bonds.
Final Assembly:
1.
Backbone: Form two parallel backbones using alternating phosphates and deoxyribose sugars.
2.
Base Pairing: Attach the bases to the deoxyribose sugars and ensure they are paired correctly:
- Adenine (A) with Thymine (T)
- Guanine (G) with Cytosine (C)
3.
Hydrogen Bonds: Use the black lines to connect the complementary base pairs.
Example Arrangement:
-
Strand 1: Phosphate → Deoxyribose → Base (e.g., A, T, G, C)
-
Strand 2: Phosphate → Deoxyribose → Base (e.g., T, A, C, G)
- Pair the bases across the strands: A-T and G-C.
Final Answer:
The DNA model should have:
- Two antiparallel backbones formed by alternating phosphates and deoxyribose sugars.
- Correctly paired bases (A-T and G-C) connected by hydrogen bonds.
- The overall structure should resemble a double helix.
$$
\boxed{\text{See the explanation above for the step-by-step assembly.}}
$$
Parent Tip: Review the logic above to help your child master the concept of dna model worksheet.
