How do the instructions end up all over our body? Preview CT-STEM

Completely Replicate DNA

EXPLORE THE BIOLOGY:

DNA (DeoxyriboNucleic Acid) is made of two strands which wind around each other in a double helix. When DNA is replicated, the DNA strands are separated and each serves as a template (i.e. the basis for a pattern) for a new double helix.

DNA-strand-length: 30 Speed: Normal

Enzyme labels: checked Substitutions: unchecked

Nucleo labels: unchecked Free-nucleosides: 50 Time-limit: None

NOTE: Even though you are moving the proteins in this simulated cell by hand, in a real cell the proteins move randomly. This model allows the movement of molecules using the mouse to observe the effects faster. You would see the same behavior in the model but at a very slow pace if you do not move the molecules by hand.

Questions

Please answer the questions below.

Question 2.1

Can DNA polymerase attach any nucleotide, anywhere on a DNA strand?

(Hint: Try out different bases at different locations; write what works and what doesn’t.)

Question 2.2

Which nucleotides (colors, labels) will pair together? (Turn NUCLEO-LABELS on)

Question 2.3

Why do you think only certain nucleotides will pair up, but others won’t?

Question 2.4

SAQ: As mentioned above, in this model you are dragging the enzymes to the place they're needed and you can drag the nucleotides to where they need to go. In an actual cell, there is not someone dragging things where they need to be. Think back to the original replication/transcription model you worked with (pictured below) and how the nucleotides got to the right place. Which model do you think is more accurate? Why?

Notes

These notes will appear on every page in this lesson so feel free to put anything here you'd like to keep track of.