Year 10 Science (2014)

Date: Name: Partner:

Lolly DNAAim:

To investigate the structure of a DNA strand using lollies to represent each of the nucleotides.

Materials: 1 licorice strap Jellybabies, jellybeans, etc in four colours Toothpicks

Method:

1. Select 16 lollies 4 each of 4 different colours

2. Assign each base to a colour (blue = adenine, green = cytosine, etc)

3. Use the colours of the lollies to represent bases.

4. Connect pairs of bases with toothpicks using the base-pairing rule.

5. Split the licorice into 2 strands.

6. Connect all the pairs of lollies to the strand of licorice, using the ends of the toothpicks to connect them.

7. Take a photo of your ladder DNA.

8. Hold both ends of the licorice and twist to make a double helix.

9. Take a photo of you double helix DNA.

document.docx

Results:Create a coloured key that matches the coloured lollies used in class for the bases.

Key: Colour Base

Insert the 2 photos of the DNA ladder and double helix below in the table below.DNA Ladder DNA double helix

Discussion:

1. Write down the complementary strand you created in your DNA.

2. We sometimes refer to DNA as being a ladder shape that consists of rungs and backbone. Explain in details what the “rungs” and “backbone” actually are.

3. Explain what the base-pairing rule is.

4. Which type of chemical bond connects the bases to each other?

5. If there is a strand of DNA consisting of 9 bases, how many amino acids will be coded for?

6. What do amino acids create when they are chained together? Briefly explain their role in a living organism.

Conclusion: Write a short paragraph about what you learnt/consolidated in this practical.

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