Student Exploration: building DNA

Vocabulary: dual helix, DNA, enzyme, mutation, nitrogenous base, nucleoside, nucleotide,replication

Prior knowledge Questions (Do these before using the Gizmo.)

DNA is an incredible molecule that forms the basis of life on Earth. DNA molecule containinstructions for building every life organism ~ above Earth, native the tiniest bacterium to a massiveblue whale. DNA additionally has the capacity to replicate, or make copies of itself. This permits livingthings come grow and reproduce.

You are watching: How do you think a dna molecule makes a copy of itself?

Look at the DNA molecule displayed at right. What does it look like?

A twin helix strand, and a spiral staircase.

This shape is called a dual helix.

Based top top this picture, exactly how do friend think a DNA molecule makes a copy that itself? (Hint: Look in ~ the bottom 2 “rungs” the the ladder.)

The DNA strands be separate the enzyme referred to as DNA polymerase i beg your pardon copieseach strand utilizing the base-pairing rule.

Gizmo Warm-upThe structure DNA Gizmo™ allows you to build a DNAmolecule and also go through the process of DNA replication.Examine the components that make up a DNA molecule.

What are the two DNA contents shown in the Gizmo?

Nucleosides and Phosphates

A nucleoside has two parts: a pentagonal sugar (deoxyribose) and a nitrogenous basic (in color). Once a nucleoside is joined to a phosphate, it is referred to as a nucleotide.

How countless different nitrogenous bases carry out you see? Four various nitrogenous bases

Note: The name of these nitrogenous bases space adenine (red), cytosine (yellow), guanine(blue), and thymine (green).

“Daughter DNA molecules”

Activity A:

Build a DNAmolecule

Get the Gizmo ready:

 If necessary, click Reset to begin the building


Question: What is the structure of DNA?

Build : monitor the steps given in the Gizmo to construct a molecule of DNA. (Note: because that simplicity, this DNA molecule is presented in 2 dimensions, there is no the twist.)

Stop once the note reads: “The DNA molecule iscomplete.” In the spaces at right, list the sequenceof nitrogenous bases on the left-hand side of theDNA molecule and also the right-hand side.

Take a photo : Click the camera ( ) in ~ upper right to take a snapshot of her DNA molecule. Open up a blank word-processing document, and select paste. Label this picture “Original DNA molecule.”

Left side ideal side









Explain : explain the framework of the DNA molecule friend made.

A. What renders up the political parties of the DNA molecule? Phosphates

B. What renders up the “rungs” of the DNA molecule? Nucleosides

Fill in : compose the surname of the nitrogenous base the joins to each of the bases below:

Adenine (A) joins to Thymine (T) Thymine (T) join to adenine (A)

Activity B:


Get the Gizmo ready:

 Be sure the note reads: “The DNA molecule is complete.”

If not, click Reset and build a brand-new DNA molecule.

Question: just how does DNA make a copy that itself?

Observe : one enzyme is a protein that facilitates specific cell processes. Click relax enzyme to relax DNA helicase. What go this enzyme do to the DNA molecule?

It splits increase the bases from your pairs

Observe : Click relax enzyme to relax DNA polymerase.

A. Notification that two groups of Nucleotides appear on the right. What space the 3 parts

of a nucleotide? Ribose sugar, a phosphate molecule, and also one of four nitrogenous

bases: adenine, guanine, cytosine or uracil.

B. Drag one of the nucleotides come a corresponding nitrogenous basic on one of the two

strands. What is the role of DNA polymerase in this process? The main role of

DNA polymerase is to make DNA from nucleotides, the structure blocks the DNA.

Build : finish the two molecules that DNA through dragging nucleotides to their equivalent locations. When you have finished, compare the two completed daughter DNA molecules.

What carry out you notice about the 2 molecules? lock both shows the DNA molecule strand

Take a photo : Click the camera to take a photo of the DNA molecules, and also paste the picture into her document. Brand this photo “Daughter DNA molecules.”

How carry out these molecules compare to the original?It mirrors the DNA molecule showing a complete DNA molecules because that the daughter cell

“Daughter DNA molecules”

Think and also discuss : Why is DNA replication such crucial process? since so countless molecules are involved in the process.

See more: The Eighteenth Amendment, &Quot;Prohibition,&Quot; Was Reversed By The _______ Amendment.

Extend your thinking : sometimes errors called mutations occur during DNA replication. What are several of the possible consequences of mutations?

A mutation is a permanent readjust in the succession of DNA. In order because that an observableeffect, mutations must occur in gene exons or regulation elements.