Exam (elaborations) GIZMO Copy of M5 L1 Gizmo Lab Building DNA

Exam (elaborations) GIZMO Copy of M5 L1 Gizmo Lab Building DNA Prior Knowledge Questions (Do these BEFORE using the Gizmo.) DNA is an incredible molecule that forms the basis of life on Earth. DNA molecules contain instructions for building every living organism on Earth, from the tiniest bacterium to a massive blue whale. DNA also has the ability to replicate, or make copies of itself. This allows living things to grow and reproduce. Look at the DNA molecule shown at right. What does it look like? A double helix where two strands are twisting around each other. Based on this picture, how do you think a DNA molecule makes a copy of itself? (Hint: Look at the bottom two “rungs” of the ladder.) I would think the two rungs at the bottom of the ladder would connect to create a copy of the DNA molecule. Gizmo Warm-up The Building DNA Gizmo™ allows you to construct a DNA molecule and go through the process of DNA replication. Examine the components that make up a DNA molecule. What are the two DNA components shown in the Gizmo? A pentagonal sugar and a nitrogenous base. A nucleoside has two parts: a pentagonal sugar (deoxyribose) and a nitrogenous base (in color). When a nucleoside is joined to a phosphate, it is called a nucleotide. How many different nitrogenous bases do you see? 4 Note: The names of these nitrogenous bases are adenine (red), cytosine (yellow), guanine (blue), and thymine (green). Revised by NVLA: 06/10/2017 GIZMO Copy of M5 L1 Gizmo Lab Building DNA M5 L1: Gizmo Lab Building DNA Activity A: Build a DNA molecule Get the Gizmo ready: · If necessary, click Reset to start the building process. Question: What is the structure of DNA? Build: Follow the steps given in the Gizmo to construct a molecule of DNA. (Note: For simplicity, this DNA molecule is shown in two dimensions, without the twist.) Stop when the hint reads: “The DNA molecule is complete.” In the table below, list the sequence of nitrogenous bases on the left-hand side of the DNA molecule and the right-hand side. Left side Right side Take a picture: Click the camera () to take a snapshot of your DNA molecule. Right-click the image and select Copy Image. Paste the image into the space to the right Revised by NVLA: 06/10/2017 M5 L1: Gizmo Lab Building DNA Explain: Describe the structure of the DNA molecule you made. What makes up the sides of the DNA molecule? The sides of the DNA molecule’s are nucleotides. What makes up the “rungs” of the DNA molecule? adenine (A), cytosine (C), guanine (G) and thymine (T). Fill in: Write the name of the nitrogenous base that joins to each of the bases below: Adenine (A) joins to: (U) Cytosine (C) joins to: (G) Thymine (T) joins to: (A) Guanine (G) joins to: (C) Practice: The left side of a DNA molecule is shown. Insert a complementary right side of the molecule for each base. A G U A C U C G Challenge: This DNA strand consists of eight pairs of nitrogenous bases. How many different sequences of eight bases can you make? Explain how you found your answer. 65,536. This has been proven throughout time and practice. Revised by NVLA: 06/10/2017 M5 L1: Gizmo Lab Building DNA Activity B: DNA replication Get the Gizmo ready: · Be sure the hint reads: “The DNA molecule is complete.” If not, click Reset and build a new DNA molecule. Question: How does DNA make a copy of itself? Observe: An enzyme is a protein that facilitates certain cell processes. Click Release enzyme to release DNA helicase. What does this enzyme do to the DNA molecule? The DNA helicase unravels the DNA molecule more and more. Observe: Click Release enzyme to release DNA polymerase. Notice that two groups of Nucleotides appear on the right. What are the three parts of a nucleotide? nitrogenous base, a sugar, and a phosphate group. Drag one of the nucleotides to a corresponding nitrogenous base on one of the two strands. What is the role of DNA polymerase in this process? It’s the primary enzyme for replication, and its role is the polymerization of dNTP's or deoxyribonucleotides, and to proofread the new copies. Build: Complete the two molecules of DNA by dragging nucleotides to their corresponding locations. When you have finished, compare the two completed daughter DNA molecules. What do you notice about the two molecules? They’re very different in that they’ve got different bases and phenotypes. Take a picture: Click the camera to take a snapshot of the DNA molecules. Paste the image into the space to the right How do these molecules compare to the original? The molecules have different bases. Think and discuss: Why is DNA replication such an important process?